diff options
Diffstat (limited to 'doc')
-rw-r--r-- | doc/src/guide/architecture.asciidoc (renamed from doc/src/guide/architecture.ezdoc) | 11 | ||||
-rw-r--r-- | doc/src/guide/book.asciidoc | 72 | ||||
-rw-r--r-- | doc/src/guide/broken_clients.asciidoc (renamed from doc/src/guide/broken_clients.ezdoc) | 17 | ||||
-rw-r--r-- | doc/src/guide/constraints.asciidoc (renamed from doc/src/guide/constraints.ezdoc) | 19 | ||||
-rw-r--r-- | doc/src/guide/cookies.asciidoc (renamed from doc/src/guide/cookies.ezdoc) | 49 | ||||
-rw-r--r-- | doc/src/guide/erlang_beginners.asciidoc (renamed from doc/src/guide/erlang_beginners.ezdoc) | 11 | ||||
-rw-r--r-- | doc/src/guide/erlang_web.asciidoc (renamed from doc/src/guide/erlang_web.ezdoc) | 13 | ||||
-rw-r--r-- | doc/src/guide/getting_started.asciidoc (renamed from doc/src/guide/getting_started.ezdoc) | 99 | ||||
-rw-r--r-- | doc/src/guide/handlers.asciidoc (renamed from doc/src/guide/handlers.ezdoc) | 44 | ||||
-rw-r--r-- | doc/src/guide/hooks.asciidoc (renamed from doc/src/guide/hooks.ezdoc) | 15 | ||||
-rw-r--r-- | doc/src/guide/index.ezdoc | 58 | ||||
-rw-r--r-- | doc/src/guide/introduction.asciidoc (renamed from doc/src/guide/introduction.ezdoc) | 13 | ||||
-rw-r--r-- | doc/src/guide/loop_handlers.asciidoc (renamed from doc/src/guide/loop_handlers.ezdoc) | 37 | ||||
-rw-r--r-- | doc/src/guide/middlewares.asciidoc (renamed from doc/src/guide/middlewares.ezdoc) | 11 | ||||
-rw-r--r-- | doc/src/guide/modern_web.asciidoc (renamed from doc/src/guide/modern_web.ezdoc) | 25 | ||||
-rw-r--r-- | doc/src/guide/multipart.asciidoc (renamed from doc/src/guide/multipart.ezdoc) | 33 | ||||
-rw-r--r-- | doc/src/guide/overview.asciidoc (renamed from doc/src/guide/overview.ezdoc) | 25 | ||||
-rw-r--r-- | doc/src/guide/req.asciidoc (renamed from doc/src/guide/req.ezdoc) | 98 | ||||
-rw-r--r-- | doc/src/guide/req_body.asciidoc (renamed from doc/src/guide/req_body.ezdoc) | 54 | ||||
-rw-r--r-- | doc/src/guide/resource_design.asciidoc (renamed from doc/src/guide/resource_design.ezdoc) | 27 | ||||
-rw-r--r-- | doc/src/guide/resp.asciidoc (renamed from doc/src/guide/resp.ezdoc) | 76 | ||||
-rw-r--r-- | doc/src/guide/rest_flowcharts.asciidoc (renamed from doc/src/guide/rest_flowcharts.ezdoc) | 31 | ||||
-rw-r--r-- | doc/src/guide/rest_handlers.asciidoc (renamed from doc/src/guide/rest_handlers.ezdoc) | 110 | ||||
-rw-r--r-- | doc/src/guide/rest_principles.asciidoc (renamed from doc/src/guide/rest_principles.ezdoc) | 15 | ||||
-rw-r--r-- | doc/src/guide/routing.asciidoc (renamed from doc/src/guide/routing.ezdoc) | 79 | ||||
-rw-r--r-- | doc/src/guide/static_files.asciidoc (renamed from doc/src/guide/static_files.ezdoc) | 57 | ||||
-rw-r--r-- | doc/src/guide/sub_protocols.asciidoc (renamed from doc/src/guide/sub_protocols.ezdoc) | 22 | ||||
-rw-r--r-- | doc/src/guide/ws_handlers.asciidoc (renamed from doc/src/guide/ws_handlers.ezdoc) | 54 | ||||
-rw-r--r-- | doc/src/guide/ws_protocol.asciidoc (renamed from doc/src/guide/ws_protocol.ezdoc) | 7 | ||||
-rw-r--r-- | doc/src/manual/cowboy.asciidoc | 98 | ||||
-rw-r--r-- | doc/src/manual/cowboy.ezdoc | 98 | ||||
-rw-r--r-- | doc/src/manual/cowboy_app.asciidoc (renamed from doc/src/manual/cowboy_app.ezdoc) | 10 | ||||
-rw-r--r-- | doc/src/manual/cowboy_handler.asciidoc (renamed from doc/src/manual/cowboy_handler.ezdoc) | 77 | ||||
-rw-r--r-- | doc/src/manual/cowboy_loop.asciidoc | 86 | ||||
-rw-r--r-- | doc/src/manual/cowboy_loop.ezdoc | 92 | ||||
-rw-r--r-- | doc/src/manual/cowboy_middleware.asciidoc (renamed from doc/src/manual/cowboy_middleware.ezdoc) | 31 | ||||
-rw-r--r-- | doc/src/manual/cowboy_protocol.asciidoc | 75 | ||||
-rw-r--r-- | doc/src/manual/cowboy_protocol.ezdoc | 75 | ||||
-rw-r--r-- | doc/src/manual/cowboy_req.asciidoc (renamed from doc/src/manual/cowboy_req.ezdoc) | 441 | ||||
-rw-r--r-- | doc/src/manual/cowboy_rest.asciidoc (renamed from doc/src/manual/cowboy_rest.ezdoc) | 321 | ||||
-rw-r--r-- | doc/src/manual/cowboy_router.asciidoc (renamed from doc/src/manual/cowboy_router.ezdoc) | 43 | ||||
-rw-r--r-- | doc/src/manual/cowboy_spdy.asciidoc | 42 | ||||
-rw-r--r-- | doc/src/manual/cowboy_spdy.ezdoc | 34 | ||||
-rw-r--r-- | doc/src/manual/cowboy_static.asciidoc | 41 | ||||
-rw-r--r-- | doc/src/manual/cowboy_static.ezdoc | 32 | ||||
-rw-r--r-- | doc/src/manual/cowboy_sub_protocol.asciidoc | 27 | ||||
-rw-r--r-- | doc/src/manual/cowboy_sub_protocol.ezdoc | 27 | ||||
-rw-r--r-- | doc/src/manual/cowboy_websocket.asciidoc (renamed from doc/src/manual/cowboy_websocket.ezdoc) | 136 | ||||
-rw-r--r-- | doc/src/manual/http_status_codes.asciidoc (renamed from doc/src/manual/http_status_codes.ezdoc) | 64 | ||||
-rw-r--r-- | doc/src/manual/index.ezdoc | 18 |
50 files changed, 1504 insertions, 1546 deletions
diff --git a/doc/src/guide/architecture.ezdoc b/doc/src/guide/architecture.asciidoc index 745505a..416ef36 100644 --- a/doc/src/guide/architecture.ezdoc +++ b/doc/src/guide/architecture.asciidoc @@ -1,11 +1,12 @@ -::: Architecture +[[architecture]] +== Architecture Cowboy is a lightweight HTTP server. It is built on top of Ranch. Please see the Ranch guide for more information. -:: One process per connection +=== One process per connection It uses only one process per connection. The process where your code runs is the process controlling the socket. Using one process @@ -20,7 +21,7 @@ up before terminating the handling of the current request. This may include cleaning up the process dictionary, timers, monitoring and more. -:: Binaries +=== Binaries It uses binaries. Binaries are more efficient than lists for representing strings because they take less memory space. Processing @@ -28,14 +29,14 @@ performance can vary depending on the operation. Binaries are known for generally getting a great boost if the code is compiled natively. Please see the HiPE documentation for more details. -:: Date header +=== Date header Because querying for the current date and time can be expensive, Cowboy generates one `Date` header value every second, shares it to all other processes, which then simply copy it in the response. This allows compliance with HTTP/1.1 with no actual performance loss. -:: Max connections +=== Max connections By default the maximum number of active connections is set to a generally accepted big enough number. This is meant to prevent having diff --git a/doc/src/guide/book.asciidoc b/doc/src/guide/book.asciidoc new file mode 100644 index 0000000..15aa42b --- /dev/null +++ b/doc/src/guide/book.asciidoc @@ -0,0 +1,72 @@ +// a2x: --dblatex-opts "-P latex.output.revhistory=0 -P doc.publisher.show=0 -P index.numbered=0" +// a2x: -d book --attribute tabsize=4 + += Cowboy User Guide + += Rationale + +include::modern_web.asciidoc[The modern Web] + +include::erlang_web.asciidoc[Erlang and the Web] + += Introduction + +include::introduction.asciidoc[Introduction] + +include::getting_started.asciidoc[Getting started] + +include::overview.asciidoc[Request overview] + +include::erlang_beginners.asciidoc[Erlang for beginners] + += Configuration + +include::routing.asciidoc[routing] + +include::constraints.asciidoc[Constraints] + +include::static_files.asciidoc[Static files] + += Request and response + +include::handlers.asciidoc[Handlers] + +include::loop_handlers.asciidoc[Loop handlers] + +include::req.asciidoc[The Req object] + +include::req_body.asciidoc[Reading the request body] + +include::resp.asciidoc[Sending a response] + +include::cookies.asciidoc[Using cookies] + +include::multipart.asciidoc[Multipart] + += REST + +include::rest_principles.asciidoc[REST principles] + +include::rest_handlers.asciidoc[Handling REST requests] + +include::rest_flowcharts.asciidoc[REST flowcharts] + +include::resource_design.asciidoc[Designing a resource handler] + += Websocket + +include::ws_protocol.asciidoc[The Websocket protocol] + +include::ws_handlers.asciidoc[Handling Websocket connections] + += Internals + +include::architecture.asciidoc[Architecture] + +include::broken_clients.asciidoc[Dealing with broken clients] + +include::middlewares.asciidoc[Middlewares] + +include::sub_protocols.asciidoc[Sub protocols] + +include::hooks.asciidoc[Hooks] diff --git a/doc/src/guide/broken_clients.ezdoc b/doc/src/guide/broken_clients.asciidoc index c508358..e91e9a2 100644 --- a/doc/src/guide/broken_clients.ezdoc +++ b/doc/src/guide/broken_clients.asciidoc @@ -1,4 +1,5 @@ -::: Dealing with broken clients +[[broken_clients]] +== Dealing with broken clients There exists a very large number of implementations for the HTTP protocol. Most widely used clients, like browsers, @@ -15,7 +16,7 @@ That means clients that ignore the HTTP standard completely may fail to understand Cowboy's responses. There are of course workarounds. This chapter aims to cover them. -:: Lowercase headers +=== Lowercase headers Cowboy converts all headers it receives to lowercase, and similarly sends back headers all in lowercase. Some broken @@ -24,19 +25,20 @@ HTTP clients have issues with that. A simple way to solve this is to create an `onresponse` hook that will format the header names with the expected case. -``` erlang +[source,erlang] +---- capitalize_hook(Status, Headers, Body, Req) -> Headers2 = [{cowboy_bstr:capitalize_token(N), V} || {N, V} <- Headers], cowboy_req:reply(Status, Headers2, Body, Req). -``` +---- Note that SPDY clients do not have that particular issue because the specification explicitly says all headers are lowercase, unlike HTTP which allows any case but treats them as case insensitive. -:: Camel-case headers +=== Camel-case headers Sometimes it is desirable to keep the actual case used by clients, for example when acting as a proxy between two broken @@ -44,7 +46,7 @@ implementations. There is no easy solution for this other than forking the project and editing the `cowboy_protocol` file directly. -:: Chunked transfer-encoding +=== Chunked transfer-encoding Sometimes an HTTP client advertises itself as HTTP/1.1 but does not support chunked transfer-encoding. This is invalid @@ -55,6 +57,5 @@ Req object response state to `waiting_stream`, Cowboy will understand that it must use the identity transfer-encoding when replying, just like if it was an HTTP/1.0 client. -``` erlang +[source,erlang] Req2 = cowboy_req:set(resp_state, waiting_stream). -``` diff --git a/doc/src/guide/constraints.ezdoc b/doc/src/guide/constraints.asciidoc index a05f489..0ae01d5 100644 --- a/doc/src/guide/constraints.ezdoc +++ b/doc/src/guide/constraints.asciidoc @@ -1,4 +1,5 @@ -::: Constraints +[[constraints]] +== Constraints Cowboy provides an optional constraints based validation feature when interacting with user input. @@ -16,7 +17,7 @@ Finally, constraints can be used to not only validate input, but also convert said input into proper Erlang terms, all in one step. -:: Structure +=== Structure Constraints are provided as a list of fields and for each field a list of constraints for that field can be provided. @@ -32,14 +33,16 @@ All constraints for a field will be used to match its value in the order they are given. If the value is modified by a constraint, the next constraint receives the updated value. -:: Built-in constraints +=== Built-in constraints -|| Constraint Description -| -| int Convert binary value to integer -| nonempty Ensures the binary value is non-empty +[cols="<,<",options="header"] +|=== +| Constraint | Description +| int | Convert binary value to integer. +| nonempty | Ensures the binary value is non-empty. +|=== -:: Custom constraint +=== Custom constraint In addition to the predefined constraints, Cowboy will accept a fun. This fun must accept one argument and return one of diff --git a/doc/src/guide/cookies.ezdoc b/doc/src/guide/cookies.asciidoc index e6d1aeb..6068db3 100644 --- a/doc/src/guide/cookies.ezdoc +++ b/doc/src/guide/cookies.asciidoc @@ -1,4 +1,5 @@ -::: Using cookies +[[cookies]] +== Using cookies Cookies are a mechanism allowing applications to maintain state on top of the stateless HTTP protocol. @@ -48,69 +49,73 @@ that run from HTTPS webpages. Finally, cookies can be restricted to HTTP and HTTPS requests, essentially disabling their access from client-side scripts. -:: Setting cookies +=== Setting cookies By default, cookies you set are defined for the session. -``` erlang +[source,erlang] SessionID = generate_session_id(), Req2 = cowboy_req:set_resp_cookie(<<"sessionid">>, SessionID, [], Req). -``` You can also make them expire at a specific point in the future. -``` erlang +[source,erlang] +---- SessionID = generate_session_id(), Req2 = cowboy_req:set_resp_cookie(<<"sessionid">>, SessionID, [ {max_age, 3600} ], Req). -``` +---- You can delete cookies that have already been set. The value is ignored. -``` erlang +[source,erlang] +---- Req2 = cowboy_req:set_resp_cookie(<<"sessionid">>, <<>>, [ {max_age, 0} ], Req). -``` +---- You can restrict them to a specific domain and path. For example, the following cookie will be set for the domain `my.example.org` and all its subdomains, but only on the path `/account` and all its subdirectories. -``` erlang +[source,erlang] +---- Req2 = cowboy_req:set_resp_cookie(<<"inaccount">>, <<"1">>, [ {domain, "my.example.org"}, {path, "/account"} ], Req). -``` +---- You can restrict the cookie to secure channels, typically HTTPS. -``` erlang +[source,erlang] +---- SessionID = generate_session_id(), Req2 = cowboy_req:set_resp_cookie(<<"sessionid">>, SessionID, [ {secure, true} ], Req). -``` +---- You can restrict the cookie to client-server communication only. Such a cookie will not be available to client-side scripts. -``` erlang +[source,erlang] +---- SessionID = generate_session_id(), Req2 = cowboy_req:set_resp_cookie(<<"sessionid">>, SessionID, [ {http_only, true} ], Req). -``` +---- Cookies may also be set client-side, for example using Javascript. -:: Reading cookies +=== Reading cookies As we said, the client sends cookies with every request. But unlike the server, the client only sends the cookie @@ -124,16 +129,14 @@ to the values or providing a default if they are missing. You can parse the cookies and then use standard library functions to access individual values. -``` erlang +[source,erlang] Cookies = cowboy_req:parse_cookies(Req), {_, Lang} = lists:keyfind(<<"lang">>, 1, Cookies). -``` You can match the cookies into a map. -``` erlang +[source,erlang] #{id := ID, lang := Lang} = cowboy_req:match_cookies([id, lang], Req). -``` You can use constraints to validate the values while matching them. The following snippet will crash if the `id` cookie is @@ -141,22 +144,20 @@ not an integer number or if the `lang` cookie is empty. Additionally the `id` cookie value will be converted to an integer term, saving you a conversion step. -``` erlang +[source,erlang] CookiesMap = cowboy_req:match_cookies([{id, int}, {lang, nonempty}], Req). -``` Note that if two cookies share the same name, then the map value will be a list of the two cookie values. -Read more about ^constraints^. +Read more about xref:constraints[constraints]. A default value can be provided. The default will be used if the `lang` cookie is not found. It will not be used if the cookie is found but has an empty value. -``` erlang +[source,erlang] #{lang := Lang} = cowboy_req:match_cookies([{lang, [], <<"en-US">>}], Req). -``` If no default is provided and the value is missing, the query string is deemed invalid and the process will crash. diff --git a/doc/src/guide/erlang_beginners.ezdoc b/doc/src/guide/erlang_beginners.asciidoc index 74d3470..b9a6c65 100644 --- a/doc/src/guide/erlang_beginners.ezdoc +++ b/doc/src/guide/erlang_beginners.asciidoc @@ -1,4 +1,5 @@ -::: Erlang for beginners +[[erlang_beginners]] +== Erlang for beginners Chances are you are interested in using Cowboy, but have no idea how to write an Erlang program. Fear not! This @@ -8,10 +9,10 @@ We recommend two books for beginners. You should read them both at some point, as they cover Erlang from two entirely different perspectives. -:: Learn You Some Erlang for Great Good! +=== Learn You Some Erlang for Great Good! The quickest way to get started with Erlang is by reading -a book with the funny name of ^"LYSE^http://learnyousomeerlang.com^, +a book with the funny name of http://learnyousomeerlang.com[LYSE], as we affectionately call it. It will get right into the syntax and quickly answer the questions @@ -22,12 +23,12 @@ You can read an early version of the book online for free, but you really should buy the much more refined paper and ebook versions. -:: Programming Erlang +=== Programming Erlang After writing some code, you will probably want to understand the very concepts that make Erlang what it is today. These are best explained by Joe Armstrong, the godfather of Erlang, -in his book ^"Programming Erlang^http://pragprog.com/book/jaerlang2/programming-erlang^. +in his book http://pragprog.com/book/jaerlang2/programming-erlang[Programming Erlang]. Instead of going into every single details of the language, Joe focuses on the central concepts behind Erlang, and shows diff --git a/doc/src/guide/erlang_web.ezdoc b/doc/src/guide/erlang_web.asciidoc index 42fcd34..91a9eca 100644 --- a/doc/src/guide/erlang_web.ezdoc +++ b/doc/src/guide/erlang_web.asciidoc @@ -1,6 +1,7 @@ -::: Erlang and the Web +[[erlang_web]] +== Erlang and the Web -:: The Web is concurrent +=== The Web is concurrent When you access a website there is little concurrency involved. A few connections are opened and requests @@ -53,7 +54,7 @@ will also connect to various applications on the Internet. Only Erlang is prepared to deal with what's coming. -:: The Web is soft real time +=== The Web is soft real time What does soft real time mean, you ask? It means we want the operations done as quickly as possible, and in the case of @@ -82,7 +83,7 @@ can guarantee stable low latency of operations. Erlang provides the guarantees that the soft real time Web requires. -:: The Web is asynchronous +=== The Web is asynchronous Long ago, the Web was synchronous because HTTP was synchronous. You fired a request, and then waited for a response. Not anymore. @@ -114,7 +115,7 @@ Erlang is by nature asynchronous and really good at it thanks to the great engineering that has been done in the VM over the years. It's only natural that it's so good at dealing with the asynchronous Web. -:: The Web is omnipresent +=== The Web is omnipresent The Web has taken a very important part of our lives. We're connected at all times, when we're on our phone, using our computer, @@ -167,7 +168,7 @@ down, or even a data center entirely. Fault tolerance and distribution are important today, and will be vital in the future of the Web. Erlang is ready. -:: Erlang is the ideal platform for the Web +=== Erlang is the ideal platform for the Web Erlang provides all the important features that the Web requires or will require in the near future. Erlang is a perfect match diff --git a/doc/src/guide/getting_started.ezdoc b/doc/src/guide/getting_started.asciidoc index deb7bf2..5d72f0a 100644 --- a/doc/src/guide/getting_started.ezdoc +++ b/doc/src/guide/getting_started.asciidoc @@ -1,4 +1,5 @@ -::: Getting started +[[getting_started]] +== Getting started Erlang is more than a language, it is also an operating system for your applications. Erlang developers rarely write standalone @@ -12,44 +13,40 @@ Cowboy, writing your first application and generating your first release. At the end of this chapter you should know everything you need to push your first Cowboy application to production. -:: Bootstrap +=== Bootstrap -We are going to use the ^"erlang.mk^https://github.com/ninenines/erlang.mk +We are going to use the https://github.com/ninenines/erlang.mk[Erlang.mk] build system. It also offers bootstrap features allowing us to quickly get started without having to deal with minute details. First, let's create the directory for our application. -``` bash +[source,bash] $ mkdir hello_erlang $ cd hello_erlang -``` -Then we need to download `erlang.mk`. Either use the following +Then we need to download Erlang.mk. Either use the following command or download it manually. -``` bash +[source,bash] $ wget https://raw.githubusercontent.com/ninenines/erlang.mk/master/erlang.mk -``` We can now bootstrap our application. Since we are going to generate a release, we will also bootstrap it at the same time. -``` bash +[source,bash] $ make -f erlang.mk bootstrap bootstrap-rel -``` This creates a Makefile, a base application, and the release files necessary for creating the release. We can already build and start this release. -``` bash -$ make -... -$ ./_rel/hello_erlang_release/bin/hello_erlang_release console +[source,bash] +---- +$ make run ... -``` +---- Entering the command `i().` will show the running processes, including one called `hello_erlang_sup`. This is the supervisor for our @@ -59,64 +56,34 @@ The release currently does nothing. In the rest of this chapter we will add Cowboy as a dependency and write a simple "Hello world!" handler. -:: Cowboy setup - -To add Cowboy as a dependency to your application, you need to modify -two files: the Makefile and the application resource file. +=== Cowboy setup -Modifying the Makefile allows the build system to know it needs to +Modifying the 'Makefile' allows the build system to know it needs to fetch and compile Cowboy. To do that we simply need to add one line to our Makefile to make it look like this: -``` Makefile +[source,make] PROJECT = hello_erlang DEPS = cowboy include erlang.mk -``` - -Modifying the application resource file, `src/hello_erlang.app.src`, -allows the build system to know it needs to include Cowboy in the -release and start it automatically. This is a different step because -some dependencies are only needed during development. - -We are simply going to add `cowboy` to the list of `applications`, -right after `stdlib`. Don't forget the comma separator. - -``` erlang -{application, hello_erlang, [ - {description, "Hello Erlang!"}, - {vsn, "0.1.0"}, - {modules, []}, - {registered, []}, - {applications, [ - kernel, - stdlib, - cowboy - ]}, - {mod, {hello_erlang_app, []}}, - {env, []} -]}. -``` - -You may want to set a description for the application while you -are editing the file. - -If you run `make` now and start the release, Cowboy will be included + +If you run `make run` now, Cowboy will be included in the release and started automatically. This is not enough however, as Cowboy doesn't do anything by default. We still need to tell Cowboy to listen for connections. -:: Listening for connections +=== Listening for connections We will do this when our application starts. It's a two step process. First we need to define and compile the dispatch list, a list of routes that Cowboy will use to map requests to handler modules. Then we tell Cowboy to listen for connections. -Open the `src/hello_erlang_app.erl` file and add the necessary +Open the 'src/hello_erlang_app.erl' file and add the necessary code to the `start/2` function to make it look like this: -``` erlang +[source,erlang] +---- start(_Type, _Args) -> Dispatch = cowboy_router:compile([ {'_', [{"/", hello_handler, []}]} @@ -125,19 +92,19 @@ start(_Type, _Args) -> [{env, [{dispatch, Dispatch}]}] ), hello_erlang_sup:start_link(). -``` +---- The dispatch list is explained in great details in the -^"Routing^routing^ chapter. For this tutorial we map the +xref:routing[Routing] chapter. For this tutorial we map the path `/` to the handler module `hello_handler`. This module doesn't exist yet, we still have to write it. -If you build the release, start it and open ^http://localhost:8080 -now, you will get an error because the module is missing. Any -other URL, like ^http://localhost:8080/test^, will result in a +If you build and start the release, then open http://localhost:8080 +in your browser, you will get an error because the module is missing. +Any other URL, like http://localhost:8080/test, will result in a 404 error. -:: Handling requests +=== Handling requests Cowboy features different kinds of handlers, including REST and Websocket handlers. For this tutorial we will use a plain @@ -145,25 +112,25 @@ HTTP handler. First, let's generate a handler from a template. -``` bash +[source,bash] $ make new t=cowboy_http n=hello_handler -``` -You can then open the `src/hello_handler.erl` file and modify +You can then open the 'src/hello_handler.erl' file and modify the `init/2` function like this to send a reply. -``` erlang +[source,erlang] +---- init(Req, Opts) -> Req2 = cowboy_req:reply(200, [{<<"content-type">>, <<"text/plain">>}], <<"Hello Erlang!">>, Req), {ok, Req2, Opts}. -``` +---- What the above code does is send a `200 OK` reply, with the `content-type` header set to `text/plain` and the response body set to `Hello Erlang!`. -If you build the release, start it and open ^http://localhost:8080 +If you run the release and open http://localhost:8080 in your browser, you should get a nice `Hello Erlang!` displayed! diff --git a/doc/src/guide/handlers.ezdoc b/doc/src/guide/handlers.asciidoc index 9336488..b6cefdd 100644 --- a/doc/src/guide/handlers.ezdoc +++ b/doc/src/guide/handlers.asciidoc @@ -1,22 +1,24 @@ -::: Handlers +[[handlers]] +== Handlers Handlers are Erlang modules that handle HTTP requests. -:: Plain HTTP handlers +=== Plain HTTP handlers The most basic handler in Cowboy implements the mandatory `init/2` callback, manipulates the request, optionally sends a response and then returns. -This callback receives the ^"Req object^req and the options -defined during the ^"router configuration^routing^. +This callback receives the xref:req[Req object] and the options +defined during the xref:routing[router configuration]. A handler that does nothing would look like this: -``` erlang +[source,erlang] +---- init(Req, _Opts) -> {ok, Req, #state{}}. -``` +---- Despite sending no reply, a `204 No Content` reply will be sent to the client, as Cowboy makes sure that a reply is @@ -24,13 +26,14 @@ sent for every request. We need to use the Req object for sending a reply. -``` erlang +[source,erlang] +---- init(Req, _Opts) -> Req2 = cowboy_req:reply(200, [ {<<"content-type">>, <<"text/plain">>} ], <<"Hello World!">>, Req), {ok, Req2, #state{}}. -``` +---- As you can see we return a 3-tuple. `ok` means that the handler ran successfully. The Req object is returned as @@ -43,7 +46,7 @@ in every subsequent callbacks to this handler. Plain HTTP handlers only have one additional callback, the optional `terminate/3`. -:: Other handlers +=== Other handlers The `init/2` callback can also be used to inform Cowboy that this is a different kind of handler and that Cowboy @@ -51,38 +54,41 @@ should switch to it. To do this you simply need to return the module name of the handler type you want to switch to. Cowboy comes with three handler types you can switch to: -^"cowboy_rest^rest_handlers^, ^"cowboy_websocket^ws_handlers^ -and ^"cowboy_loop^loop_handlers^. In addition to those you +xref:rest_handlers[cowboy_rest], xref:ws_handlers[cowboy_websocket] +and xref:loop_handlers[cowboy_loop]. In addition to those you can define your own handler types. Switching is simple. Instead of returning `ok`, you simply return the name of the handler type you want to use. The following snippet switches to a Websocket handler: -``` erlang +[source,erlang] +---- init(Req, _Opts) -> {cowboy_websocket, Req, #state{}}. -``` +---- You can also switch to your own custom handler type: -``` erlang +[source,erlang] +---- init(Req, _Opts) -> {my_handler_type, Req, #state{}}. -``` +---- How to implement a custom handler type is described in the -^"Sub protocols^sub_protocols chapter. +xref:sub_protocols[Sub protocols] chapter. -:: Cleaning up +=== Cleaning up All handlers coming with Cowboy allow the use of the optional `terminate/3` callback. -``` erlang +[source,erlang] +---- terminate(_Reason, Req, State) -> ok. -``` +---- This callback is strictly reserved for any required cleanup. You cannot send a response from this function. There is no diff --git a/doc/src/guide/hooks.ezdoc b/doc/src/guide/hooks.asciidoc index 1c19648..fc79f8a 100644 --- a/doc/src/guide/hooks.ezdoc +++ b/doc/src/guide/hooks.asciidoc @@ -1,9 +1,10 @@ -::: Hooks +[[hooks]] +== Hooks Hooks allow the user to customize Cowboy's behavior during specific operations. -:: Onresponse +=== Onresponse The `onresponse` hook is called right before sending the response to the socket. It can be used for the purposes of logging responses, @@ -16,7 +17,8 @@ explicitly provide all headers that are needed. You can specify the `onresponse` hook when creating the listener. -``` erlang +[source,erlang] +---- cowboy:start_http(my_http_listener, 100, [{port, 8080}], [ @@ -24,13 +26,14 @@ cowboy:start_http(my_http_listener, 100, {onresponse, fun ?MODULE:custom_404_hook/4} ] ). -``` +---- The following hook function will provide a custom body for 404 errors when it has not been provided before, and will let Cowboy proceed with the default response otherwise. -``` erlang +[source,erlang] +---- custom_404_hook(404, Headers, <<>>, Req) -> Body = <<"404 Not Found.">>, Headers2 = lists:keyreplace(<<"content-length">>, 1, Headers, @@ -38,6 +41,6 @@ custom_404_hook(404, Headers, <<>>, Req) -> cowboy_req:reply(404, Headers2, Body, Req); custom_404_hook(_, _, _, Req) -> Req. -``` +---- Again, make sure to always return the last request object obtained. diff --git a/doc/src/guide/index.ezdoc b/doc/src/guide/index.ezdoc deleted file mode 100644 index dbe75ff..0000000 --- a/doc/src/guide/index.ezdoc +++ /dev/null @@ -1,58 +0,0 @@ -::: Cowboy User Guide - -The Cowboy User Guide explores the modern Web and how to make -best use of Cowboy for writing powerful Web applications. - -:: Rationale - -* ^"The modern Web^modern_web -* ^"Erlang and the Web^erlang_web - -:: Introduction - -* ^"Introduction^introduction -* ^"Getting started^getting_started -* ^"Request overview^overview -* ^"Erlang for beginners^erlang_beginners - -:: Configuration - -* ^"Routing^routing -* ^"Constraints^constraints -* ^"Static files^static_files - -:: Request and response - -* ^"Handlers^handlers -* ^"The Req object^req -* ^"Reading the request body^req_body -* ^"Sending a response^resp -* ^"Using cookies^cookies -* ^"Multipart^multipart - -:: REST - -* ^"REST principles^rest_principles -* ^"Handling REST requests^rest_handlers -* ^"REST flowcharts^rest_flowcharts -* ^"Designing a resource handler^resource_design - -:: Websocket - -* ^"The Websocket protocol^ws_protocol -* ^"Handling Websocket connections^ws_handlers - -:: Push technology - -* ^"Loop handlers^loop_handlers - -:: Extensions - -* ^"Middlewares^middlewares -* ^"Sub protocols^sub_protocols -* ^"Hooks^hooks - -:: Internals - -* ^"Architecture^architecture -* ^"Dealing with broken clients^broken_clients diff --git a/doc/src/guide/introduction.ezdoc b/doc/src/guide/introduction.asciidoc index e1d2e60..0ffeb91 100644 --- a/doc/src/guide/introduction.ezdoc +++ b/doc/src/guide/introduction.asciidoc @@ -1,4 +1,5 @@ -::: Introduction +[[introduction]] +== Introduction Cowboy is a small, fast and modular HTTP server written in Erlang. @@ -14,14 +15,14 @@ Cowboy is clean Erlang code. It includes hundreds of tests and its code is fully compliant with the Dialyzer. It is also well documented and features both a Function Reference and a User Guide. -:: Prerequisites +=== Prerequisites Beginner Erlang knowledge is recommended for reading this guide. Knowledge of the HTTP protocol is recommended but not required, as it will be detailed throughout the guide. -:: Supported platforms +=== Supported platforms Cowboy is tested and supported on Linux. @@ -39,11 +40,11 @@ modifications but there is no guarantee that it will work as expected. Cowboy uses the maps data type which was introduced in Erlang 17.0. -:: Versioning +=== Versioning -Cowboy uses ^"Semantic Versioning 2.0.0^http://semver.org/^. +Cowboy uses http://semver.org/[Semantic Versioning 2.0.0]. -:: Conventions +=== Conventions In the HTTP protocol, the method name is case sensitive. All standard method names are uppercase. diff --git a/doc/src/guide/loop_handlers.ezdoc b/doc/src/guide/loop_handlers.asciidoc index 47893a9..58c4223 100644 --- a/doc/src/guide/loop_handlers.ezdoc +++ b/doc/src/guide/loop_handlers.asciidoc @@ -1,4 +1,5 @@ -::: Loop handlers +[[loop_handlers]] +== Loop handlers Loop handlers are a special kind of HTTP handlers used when the response can not be sent right away. The handler enters instead @@ -24,7 +25,7 @@ and feed these messages to the `info/3` callback. It also features the `init/2` and `terminate/3` callbacks which work the same as for plain HTTP handlers. -:: Initialization +=== Initialization The `init/2` function must return a `cowboy_loop` tuple to enable loop handler behavior. This tuple may optionally contain @@ -33,21 +34,23 @@ process enter hibernation until a message is received. This snippet enables the loop handler. -``` erlang +[source,erlang] +---- init(Req, _Opts) -> {cowboy_loop, Req, #state{}}. -``` +---- However it is largely recommended that you set a timeout value. The next example sets a timeout value of 30s and also makes the process hibernate. -``` erlang +[source,erlang] +---- init(Req, _Opts) -> {cowboy_loop, Req, #state{}, 30000, hibernate}. -``` +---- -:: Receive loop +=== Receive loop Once initialized, Cowboy will wait for messages to arrive in the process' mailbox. When a message arrives, Cowboy @@ -58,13 +61,14 @@ The following snippet sends a reply when it receives a `reply` message from another process, or waits for another message otherwise. -``` erlang +[source,erlang] +---- info({reply, Body}, Req, State) -> Req2 = cowboy_req:reply(200, [], Body, Req), {stop, Req2, State}; info(_Msg, Req, State) -> {ok, Req, State, hibernate}. -``` +---- Do note that the `reply` tuple here may be any message and is simply an example. @@ -81,7 +85,7 @@ This will instruct Cowboy to end the request. Otherwise an `ok` tuple should be returned. -:: Streaming loop +=== Streaming loop Another common case well suited for loop handlers is streaming data received in the form of Erlang messages. @@ -93,7 +97,8 @@ The following snippet does exactly that. As you can see a chunk is sent every time a `chunk` message is received, and the loop is stopped by sending an `eof` message. -``` erlang +[source,erlang] +---- init(Req, _Opts) -> Req2 = cowboy_req:chunked_reply(200, [], Req), {cowboy_loop, Req2, #state{}}. @@ -105,18 +110,18 @@ info({chunk, Chunk}, Req, State) -> {ok, Req, State}; info(_Msg, Req, State) -> {ok, Req, State}. -``` +---- -:: Cleaning up +==== Cleaning up It is recommended that you set the connection header to `close` when replying, as this process may be reused for a subsequent request. -Please refer to the ^"Handlers chapter^handlers +Please refer to the xref:handlers[Handlers chapter] for general instructions about cleaning up. -:: Timeout +=== Timeout By default Cowboy will not attempt to close the connection if there is no activity from the client. This is not always @@ -132,7 +137,7 @@ so there is a configurable limit for it. The default buffer size is of 5000 bytes, but it may be changed by setting the `loop_max_buffer` middleware environment value. -:: Hibernate +=== Hibernate To save memory, you may hibernate the process in between messages received. This is done by returning the atom diff --git a/doc/src/guide/middlewares.ezdoc b/doc/src/guide/middlewares.asciidoc index 8b047d7..e6be30d 100644 --- a/doc/src/guide/middlewares.ezdoc +++ b/doc/src/guide/middlewares.asciidoc @@ -1,4 +1,5 @@ -::: Middlewares +[[middlewares]] +== Middlewares Cowboy delegates the request processing to middleware components. By default, two middlewares are defined, for the routing and handling @@ -11,7 +12,7 @@ change the chain of middlewares as needed. Cowboy will execute all middlewares in the given order, unless one of them decides to stop processing. -:: Usage +=== Usage Middlewares only need to implement a single callback: `execute/2`. It is defined in the `cowboy_middleware` behavior. @@ -34,7 +35,7 @@ to send an error back to the socket, the process will just crash. It is up to the middleware to make sure that a reply is sent if something goes wrong. -:: Configuration +=== Configuration The middleware environment is defined as the `env` protocol option. In the previous chapters we saw it briefly when we needed to pass @@ -56,13 +57,13 @@ environment values to perform. You can update the environment by calling the `cowboy:set_env/3` convenience function, adding or replacing a value in the environment. -:: Routing middleware +=== Routing middleware The routing middleware requires the `dispatch` value. If routing succeeds, it will put the handler name and options in the `handler` and `handler_opts` values of the environment, respectively. -:: Handler middleware +=== Handler middleware The handler middleware requires the `handler` and `handler_opts` values. It puts the result of the request handling into `result`. diff --git a/doc/src/guide/modern_web.ezdoc b/doc/src/guide/modern_web.asciidoc index 1c2c342..7dc812b 100644 --- a/doc/src/guide/modern_web.ezdoc +++ b/doc/src/guide/modern_web.asciidoc @@ -1,4 +1,5 @@ -::: The modern Web +[[modern_web]] +== The modern Web Let's take a look at various technologies from the beginnings of the Web up to this day, and get a preview of what's @@ -8,7 +9,7 @@ Cowboy is compatible with all the technology cited in this chapter except of course HTTP/2.0 which has no implementation in the wild at the time of writing. -:: The prehistoric Web +=== The prehistoric Web HTTP was initially created to serve HTML pages and only had the GET method for retrieving them. This initial @@ -29,7 +30,7 @@ this. Most improvements done in recent years focused on reducing this load time and reducing the latency of the requests. -:: HTTP/1.1 +=== HTTP/1.1 HTTP/1.1 quickly followed and added a keep-alive mechanism to allow using the same connection for many requests, as @@ -47,7 +48,7 @@ clients to perform what is called as pipelining: sending many requests in a row, and then processing the responses which will be received in the same order as the requests. -:: REST +=== REST The design of HTTP/1.1 was influenced by the REST architectural style. REST, or REpresentational State Transfer, is a style of @@ -72,7 +73,7 @@ to implement RESTful systems. REST is most often used when designing web application APIs which are generally meant to be used by executable code directly. -:: XmlHttpRequest +=== XmlHttpRequest Also know as AJAX, this technology allows Javascript code running on a web page to perform asynchronous requests to the server. @@ -88,7 +89,7 @@ This is of course still requests initiated by the client, the server still had no way of pushing data to the client on its own, so new technology appeared to allow that. -:: Long-polling +=== Long-polling Polling was a technique used to overcome the fact that the server cannot push data directly to the client. Therefore the client had @@ -116,7 +117,7 @@ You probably guessed by now that long-polling is a hack, and like most hacks it can suffer from unforeseen issues, in this case it doesn't always play well with proxies. -:: HTML5 +=== HTML5 HTML5 is, of course, the HTML version after HTML4. But HTML5 emerged to solve a specific problem: dynamic web applications. @@ -140,7 +141,7 @@ events from the server. The solution went on to become HTML5. At the time of writing it is being standardized. -:: EventSource +=== EventSource EventSource, sometimes also called Server-Sent Events, is a technology allowing servers to push data to HTML5 applications. @@ -159,7 +160,7 @@ UTF-8 encoded text data. Binary data and text data encoded differently are not allowed by the protocol. A heavier but more generic approach can be found in Websocket. -:: Websocket +=== Websocket Websocket is a protocol built on top of HTTP/1.1 that provides a two-ways communication channel between the client and the @@ -179,7 +180,7 @@ A Websocket connection can be used to transfer any kind of data, small or big, text or binary. Because of this Websocket is sometimes used for communication between systems. -:: SPDY +=== SPDY SPDY is an attempt to reduce page loading time by opening a single connection per server, keeping it open for subsequent @@ -203,7 +204,7 @@ to a SPDY connection seamlessly if the protocol supports it. The protocol itself has a few shortcomings which are being fixed in HTTP/2.0. -:: HTTP/2.0 +=== HTTP/2.0 HTTP/2.0 is the long-awaited update to the HTTP/1.1 protocol. It is based on SPDY although a lot has been improved at the @@ -211,5 +212,3 @@ time of writing. HTTP/2.0 is an asynchronous two-ways communication channel between two endpoints. - -It is planned to be ready late 2014. diff --git a/doc/src/guide/multipart.ezdoc b/doc/src/guide/multipart.asciidoc index d0b2e40..20d53d5 100644 --- a/doc/src/guide/multipart.ezdoc +++ b/doc/src/guide/multipart.asciidoc @@ -1,4 +1,5 @@ -::: Multipart requests +[[multipart]] +== Multipart requests Multipart originates from MIME, an Internet standard that extends the format of emails. Multipart messages are a @@ -24,7 +25,7 @@ Req object directly. Cowboy defines two functions that allows you to get information about each part and read their contents. -:: Structure +=== Structure A multipart message is a list of parts. Parts may contain either a multipart message or a non-multipart @@ -32,7 +33,7 @@ content-type. This allows parts to be arranged in a tree structure, although this is a rare case as far as the Web is concerned. -:: Form-data +=== Form-data In the normal case, when a form is submitted, the browser will use the `application/x-www-form-urlencoded` @@ -55,7 +56,7 @@ of the files it sends this way, but you should not rely on it for determining the contents of the file. Proper investigation of the contents is recommended. -:: Checking the content-type +=== Checking the content-type While there is a variety of multipart messages, the most common on the Web is `multipart/form-data`. It's @@ -65,18 +66,20 @@ allows uploading files. You can quickly figure out if a multipart message has been sent by parsing the `content-type` header. -``` erlang +[source,erlang] +---- {<<"multipart">>, <<"form-data">>, _} = cowboy_req:parse_header(<<"content-type">>, Req). -``` +---- -:: Reading a multipart message +=== Reading a multipart message To read a message you have to iterate over all its parts. Then, for each part, you can inspect its headers and read its body. -``` erlang +[source,erlang] +---- multipart(Req) -> case cowboy_req:part(Req) of {ok, _Headers, Req2} -> @@ -85,7 +88,7 @@ multipart(Req) -> {done, Req2} -> Req2 end. -``` +---- Parts do not have a size limit. When a part body is too big, Cowboy will return what it read so far and @@ -100,7 +103,8 @@ is a file being uploaded. This can be used for example to allow large part bodies for files but crash when a normal field is too large. -``` erlang +[source,erlang] +---- multipart(Req) -> case cowboy_req:part(Req) of {ok, Headers, Req2} -> @@ -123,14 +127,14 @@ stream_file(Req) -> {more, _Body, Req2} -> stream_file(Req2) end. -``` +---- By default the body chunk Cowboy will return is limited to 8MB. This can of course be overriden. Both functions can take a second argument, the same list of options that will be passed to `cowboy_req:body/2` function. -:: Skipping unwanted parts +=== Skipping unwanted parts If you do not want to read a part's body, you can skip it. Skipping is easy. If you do not call the function to read @@ -140,7 +144,8 @@ you request the next part. The following snippet reads all part headers and skips all bodies: -``` erlang +[source,erlang] +---- multipart(Req) -> case cowboy_req:part(Req) of {ok, _Headers, Req2} -> @@ -148,7 +153,7 @@ multipart(Req) -> {done, Req2} -> Req2 end. -``` +---- Similarly, if you start reading the body and it ends up being too big, you can simply continue with the next part, diff --git a/doc/src/guide/overview.ezdoc b/doc/src/guide/overview.asciidoc index 725ae4e..b337e3d 100644 --- a/doc/src/guide/overview.ezdoc +++ b/doc/src/guide/overview.asciidoc @@ -1,10 +1,11 @@ -::: Request overview +[[overview]] +== Request overview This chapter explains the different steps a request goes through until a response is sent, along with details of the Cowboy implementation. -:: Request/response +=== Request/response As you already know, HTTP clients connect to the server and send a request for a resource; the server then sends a @@ -18,7 +19,7 @@ add like writing logs. Requests take the following route in Cowboy: -^"HTTP request/response flowchart^!http_req_resp.png +image::http_req_resp.png[HTTP request/response flowchart] This shows the default middlewares, but they may be configured differently in your setup. The dark green @@ -42,7 +43,7 @@ When a response is sent, you can optionally modify it or act upon it by enabling the `onresponse` hook. By default the response is sent directly to the client. -:: And then? +=== And then? Behavior depends on what protocol is in use. @@ -59,7 +60,7 @@ asynchronously on the same connection. Details on what this means for your application is described in this chapter. -:: Keep-alive (HTTP/1.1) +=== Keep-alive (HTTP/1.1) With HTTP/1.1, the connection may be left open for subsequent requests to come. This mechanism is called @@ -79,11 +80,12 @@ as the reply is sent. This snippet will force Cowboy to close the connection. -``` erlang +[source,erlang] +---- Req2 = cowboy_req:reply(200, [ {<<"connection">>, <<"close">>}, ], <<"Closing the socket in 3.. 2.. 1..">>, Req). -``` +---- Cowboy will only accept a certain number of new requests on the same connection. By default it will run up to 100 @@ -91,12 +93,13 @@ requests. This number can be changed by setting the `max_keepalive` configuration value when starting an HTTP listener. -``` erlang +[source,erlang] +---- cowboy:start_http(my_http_listener, 100, [{port, 8080}], [ {env, [{dispatch, Dispatch}]}, {max_keepalive, 5} ]). -``` +---- Cowboy implements the keep-alive mechanism by reusing the same process for all requests. This allows Cowboy @@ -106,7 +109,7 @@ But it also means you need to clean up if you do have code with side effects. The `terminate/3` function can be used for this purpose. -:: Pipelining (HTTP/1.1) +=== Pipelining (HTTP/1.1) While HTTP is designed as a sequential protocol, with the client sending a request and then waiting for the @@ -123,7 +126,7 @@ static files for example. This is handled automatically by the server. -:: Asynchronous requests (SPDY) +=== Asynchronous requests (SPDY) In SPDY, the client can send a request at any time. And the server can send a response at any time too. diff --git a/doc/src/guide/req.ezdoc b/doc/src/guide/req.asciidoc index add6166..09d442a 100644 --- a/doc/src/guide/req.ezdoc +++ b/doc/src/guide/req.asciidoc @@ -1,10 +1,11 @@ -::: The Req object +[[req]] +== The Req object The Req object is this variable that you will use to obtain information about a request, read the body of the request and send a response. -:: A special variable +=== A special variable While we call it an "object", it is not an object in the OOP sense of the term. In fact it is completely opaque @@ -27,7 +28,7 @@ For example, when streaming the request body, the function will return the body by chunks, one at a time, until there is none left. -:: Overview of the cowboy_req interface +=== Overview of the cowboy_req interface With the exception of functions manipulating the request body, all functions return a single value. Depending on @@ -44,7 +45,7 @@ This chapter covers the access functions mainly. Cookies, request body and response functions are covered in their own chapters. -:: Request +=== Request When a client performs a request, it first sends a few required values. They are sent differently depending on the protocol @@ -56,31 +57,28 @@ The method identifies the action. Standard methods include GET, HEAD, OPTIONS, PATCH, POST, PUT, DELETE. Method names are case sensitive. -``` erlang +[source,erlang] Method = cowboy_req:method(Req). -``` The host, port and path parts of the URL identify the resource being accessed. The host and port information may not be available if the client uses HTTP/1.0. -``` erlang +[source,erlang] Host = cowboy_req:host(Req), Port = cowboy_req:port(Req), Path = cowboy_req:path(Req). -``` The version used by the client can of course also be obtained. -``` erlang +[source,erlang] Version = cowboy_req:version(Req). -``` Do note however that clients claiming to implement one version of the protocol does not mean they implement it fully, or even properly. -:: Bindings +=== Bindings After routing the request, bindings are available. Bindings are these parts of the host or path that you chose to extract @@ -89,61 +87,53 @@ when defining the routes of your application. You can fetch a single binding. The value will be `undefined` if the binding doesn't exist. -``` erlang +[source,erlang] Binding = cowboy_req:binding(my_binding, Req). -``` If you need a different value when the binding doesn't exist, you can change the default. -``` erlang +[source,erlang] Binding = cowboy_req:binding(my_binding, Req, 42). -``` You can also obtain all bindings in one call. They will be returned as a list of key/value tuples. -``` erlang +[source,erlang] AllBindings = cowboy_req:bindings(Req). -``` If you used `...` at the beginning of the route's pattern for the host, you can retrieve the matched part of the host. The value will be `undefined` otherwise. -``` erlang +[source,erlang] HostInfo = cowboy_req:host_info(Req). -``` Similarly, if you used `...` at the end of the route's pattern for the path, you can retrieve the matched part, or get `undefined` otherwise. -``` erlang +[source,erlang] PathInfo = cowboy_req:path_info(Req). -``` -:: Query string +=== Query string The raw query string can be obtained directly. -``` erlang +[source,erlang] Qs = cowboy_req:qs(Req). -``` You can parse the query string and then use standard library functions to access individual values. -``` erlang +[source,erlang] QsVals = cowboy_req:parse_qs(Req), {_, Lang} = lists:keyfind(<<"lang">>, 1, QsVals). -``` You can match the query string into a map. -``` erlang +[source,erlang] #{id := ID, lang := Lang} = cowboy_req:match_qs([id, lang], Req). -``` You can use constraints to validate the values while matching them. The following snippet will crash if the `id` value is @@ -151,9 +141,8 @@ not an integer number or if the `lang` value is empty. Additionally the `id` value will be converted to an integer term, saving you a conversion step. -``` erlang +[source,erlang] QsMap = cowboy_req:match_qs([{id, int}, {lang, nonempty}], Req). -``` Note that in the case of duplicate query string keys, the map value will become a list of the different values. @@ -164,58 +153,50 @@ A default value can be provided. The default will be used if the `lang` key is not found. It will not be used if the key is found but has an empty value. -``` erlang +[source,erlang] #{lang := Lang} = cowboy_req:match_qs([{lang, [], <<"en-US">>}], Req). -``` If no default is provided and the value is missing, the query string is deemed invalid and the process will crash. -:: Request URL +=== Request URL You can reconstruct the full URL of the resource. -``` erlang +[source,erlang] URL = cowboy_req:url(Req). -``` You can also obtain only the base of the URL, excluding the path and query string. -``` erlang +[source,erlang] BaseURL = cowboy_req:host_url(Req). -``` -:: Headers +=== Headers Cowboy allows you to obtain the header values as string, or parsed into a more meaningful representation. This will get the string value of a header. -``` erlang +[source,erlang] HeaderVal = cowboy_req:header(<<"content-type">>, Req). -``` You can of course set a default in case the header is missing. -``` erlang -HeaderVal - = cowboy_req:header(<<"content-type">>, Req, <<"text/plain">>). -``` +[source,erlang] +HeaderVal = cowboy_req:header(<<"content-type">>, Req, <<"text/plain">>). And also obtain all headers. -``` erlang +[source,erlang] AllHeaders = cowboy_req:headers(Req). -``` To parse the previous header, simply call `parse_header/{2,3}` where you would call `header/{2,3}` otherwise. -``` erlang +[source,erlang] ParsedVal = cowboy_req:parse_header(<<"content-type">>, Req). -``` Cowboy will crash if it doesn't know how to parse the given header, or if the value is invalid. @@ -224,15 +205,16 @@ You can of course define a default value. Note that the default value you specify here is the parsed value you'd like to get by default. -``` erlang +[source,erlang] +---- ParsedVal = cowboy_req:parse_header(<<"content-type">>, Req, {<<"text">>, <<"plain">>, []}). -``` +---- The list of known headers and default values is defined in the manual. -:: Meta +=== Meta Cowboy will sometimes associate some meta information with the request. Built-in meta values are listed in the manual @@ -241,29 +223,25 @@ for their respective modules. This will get a meta value. The returned value will be `undefined` if it isn't defined. -``` erlang +[source,erlang] MetaVal = cowboy_req:meta(websocket_version, Req). -``` You can change the default value if needed. -``` erlang +[source,erlang] MetaVal = cowboy_req:meta(websocket_version, Req, 13). -``` You can also define your own meta values. The name must be an `atom()`. -``` erlang +[source,erlang] Req2 = cowboy_req:set_meta(the_answer, 42, Req). -``` -:: Peer +=== Peer You can obtain the peer address and port number. This is not necessarily the actual IP and port of the client, but rather the one of the machine that connected to the server. -``` erlang +[source,erlang] {IP, Port} = cowboy_req:peer(Req). -``` diff --git a/doc/src/guide/req_body.ezdoc b/doc/src/guide/req_body.asciidoc index 8864035..d2a43d2 100644 --- a/doc/src/guide/req_body.ezdoc +++ b/doc/src/guide/req_body.asciidoc @@ -1,4 +1,5 @@ -::: Reading the request body +[[req_body]] +== Reading the request body The Req object also allows you to read the request body. @@ -16,13 +17,12 @@ parse in a single call for form urlencoded formats or multipart. All of these except multipart are covered in this chapter. Multipart is covered later on in the guide. -:: Check for request body +=== Check for request body You can check whether a body was sent with the request. -``` erlang +[source,erlang] cowboy_req:has_body(Req). -``` It will return `true` if there is a request body, and `false` otherwise. @@ -31,14 +31,13 @@ Note that it is generally safe to assume that a body is sent for `POST`, `PUT` and `PATCH` requests, without having to explicitly check for it. -:: Request body length +=== Request body length You can obtain the body length if it was sent with the request. -``` erlang +[source,erlang] Length = cowboy_req:body_length(Req). -``` The value returned will be `undefined` if the length couldn't be figured out from the request headers. If @@ -46,26 +45,23 @@ there's a body but no length is given, this means that the chunked transfer-encoding was used. You can read chunked bodies by using the stream functions. -:: Reading the body +=== Reading the body You can read the whole body directly in one call. -``` erlang +[source,erlang] {ok, Body, Req2} = cowboy_req:body(Req). -``` By default, Cowboy will attempt to read up to a size of 8MB. You can override this limit as needed. -``` erlang +[source,erlang] {ok, Body, Req2} = cowboy_req:body(Req, [{length, 100000000}]). -``` You can also disable it. -``` erlang +[source,erlang] {ok, Body, Req2} = cowboy_req:body(Req, [{length, infinity}]). -``` It is recommended that you do not disable it for public facing websites. @@ -74,7 +70,7 @@ If the body is larger than the limit, then Cowboy will return a `more` tuple instead, allowing you to stream it if you would like to. -:: Streaming the body +=== Streaming the body You can stream the request body by chunks. @@ -82,7 +78,8 @@ Cowboy returns a `more` tuple when there is more body to be read, and an `ok` tuple for the last chunk. This allows you to loop over all chunks. -``` erlang +[source,erlang] +---- body_to_console(Req) -> case cowboy_req:body(Req) of {ok, Data, Req2} -> @@ -92,12 +89,12 @@ body_to_console(Req) -> io:format("~s", [Data]), body_to_console(Req2) end. -``` +---- You can of course set the `length` option to configure the size of chunks. -:: Rate of data transmission +=== Rate of data transmission You can control the rate of data transmission by setting options when calling body functions. This applies not only @@ -110,7 +107,7 @@ to be received from the socket at once, in bytes. The `read_timeout` option defines the time Cowboy waits before that amount is received, in milliseconds. -:: Transfer and content decoding +=== Transfer and content decoding Cowboy will by default decode the chunked transfer-encoding if any. It will not decode any content-encoding by default. @@ -122,28 +119,27 @@ ignored. The following example shows how to set both options. -``` erlang +[source,erlang] +---- {ok, Data, Req2} = cowboy_req:body(Req, [ {transfer_decode, fun transfer_decode/2, TransferState}, {content_decode, fun content_decode/1} ]). -``` +---- -:: Reading a form urlencoded body +=== Reading a form urlencoded body You can directly obtain a list of key/value pairs if the body was sent using the application/x-www-form-urlencoded content-type. -``` erlang +[source,erlang] {ok, KeyValues, Req2} = cowboy_req:body_qs(Req). -``` You can then retrieve an individual value from that list. -``` erlang +[source,erlang] {_, Lang} = lists:keyfind(lang, 1, KeyValues). -``` You should not attempt to match on the list as the order of the values is undefined. @@ -152,7 +148,5 @@ By default Cowboy will reject bodies with a size above 64KB when using this function. You can override this limit by setting the `length` option. -``` erlang -{ok, KeyValues, Req2} = cowboy_req:body_qs(Req, - [{length, 2000000}]). -``` +[source,erlang] +{ok, KeyValues, Req2} = cowboy_req:body_qs(Req, [{length, 2000000}]). diff --git a/doc/src/guide/resource_design.ezdoc b/doc/src/guide/resource_design.asciidoc index 67cb09b..a8a6648 100644 --- a/doc/src/guide/resource_design.ezdoc +++ b/doc/src/guide/resource_design.asciidoc @@ -1,10 +1,11 @@ -::: Designing a resource handler +[[resource_design]] +== Designing a resource handler This chapter aims to provide you with a list of questions you must answer in order to write a good resource handler. It is meant to be usable as a step by step guide. -:: The service +=== The service Can the service become unavailable, and when it does, can we detect it? For example database connectivity problems @@ -17,7 +18,7 @@ more than the standard OPTIONS, HEAD, GET, PUT, POST, PATCH and DELETE? Are we not using one of those at all? Implement the `known_methods` callback. -:: Type of resource handler +=== Type of resource handler Am I writing a handler for a collection of resources, or for a single resource? @@ -26,7 +27,7 @@ The semantics for each of these are quite different. You should not mix collection and single resource in the same handler. -:: Collection handler +=== Collection handler Skip this section if you are not doing a collection. @@ -70,7 +71,7 @@ operation is atomic. The PATCH operation may be used for such things as reordering; adding, modifying or deleting parts of the collection. -:: Single resource handler +=== Single resource handler Skip this section if you are doing a collection. @@ -98,7 +99,7 @@ operation is atomic. The PATCH operation may be used for adding, removing or modifying specific values in the resource. -:: The resource +=== The resource Following the above discussion, implement the `allowed_methods` callback. @@ -125,7 +126,7 @@ Is there any constraints on the length of the resource URI? For example the URI may be used as a key in storage and may have a limit in length. Implement `uri_too_long`. -:: Representations +=== Representations What media types do I provide? If text based, what charsets are provided? What languages do I provide? @@ -149,7 +150,7 @@ representation available? Send a list of available representations in the response body and implement the `multiple_choices` callback. -:: Redirections +=== Redirections Do I need to keep track of what resources were deleted? For example you may have a mechanism where moving a @@ -161,7 +162,7 @@ it is explicitly temporary, for example due to maintenance, implement the `moved_temporarily` callback. Otherwise, implement the `moved_permanently` callback. -:: The request +=== The request Do we need to perform extra checks to make sure the request is valid? Cowboy will do many checks when receiving the @@ -176,20 +177,20 @@ to accept? Implement `valid_entity_length`. Finally, take a look at the sections corresponding to the methods you are implementing. -:: OPTIONS method +=== OPTIONS method Cowboy by default will send back a list of allowed methods. Do I need to add more information to the response? Implement the `options` method. -:: GET and HEAD methods +=== GET and HEAD methods If you implement the methods GET and/or HEAD, you must implement one `ProvideResource` callback for each content-type returned by the `content_types_provided` callback. -:: PUT, POST and PATCH methods +=== PUT, POST and PATCH methods If you implement the methods PUT, POST and/or PATCH, you must implement the `content_types_accepted` callback, @@ -208,7 +209,7 @@ a resource? Do we want to make sure that two updates around the same time are not cancelling one another? Implement the `is_conflict` callback. -:: DELETE methods +=== DELETE methods If you implement the method DELETE, you must implement the `delete_resource` callback. diff --git a/doc/src/guide/resp.ezdoc b/doc/src/guide/resp.asciidoc index 009756a..1ffdfbd 100644 --- a/doc/src/guide/resp.ezdoc +++ b/doc/src/guide/resp.asciidoc @@ -1,4 +1,5 @@ -::: Sending a response +[[resp]] +== Sending a response The Req object also allows you to send a response. @@ -9,36 +10,37 @@ with its body streamed by chunks of arbitrary size. You can also set headers or the response body in advance and Cowboy will use them when you finally do reply. -:: Reply +=== Reply You can send a reply with no particular headers or body. Cowboy will make sure to send the mandatory headers with the response. -``` erlang +[source,erlang] Req2 = cowboy_req:reply(200, Req). -``` You can define headers to be sent with the response. Note that header names must be lowercase. Again, Cowboy will make sure to send the mandatory headers with the response. -``` erlang +[source,erlang] +---- Req2 = cowboy_req:reply(303, [ {<<"location">>, <<"http://ninenines.eu">>} ], Req). -``` +---- You can override headers that Cowboy would send otherwise. Any header set by the user will be used over the ones set by Cowboy. For example, you can advertise yourself as a different server. -``` erlang +[source,erlang] +---- Req2 = cowboy_req:reply(200, [ {<<"server">>, <<"yaws">>} ], Req). -``` +---- We also saw earlier how to force close the connection by overriding the connection header. @@ -48,34 +50,35 @@ will automatically set the content-length header if you do. We recommend that you set the content-type header so the client may know how to read the body. -``` erlang +[source,erlang] +---- Req2 = cowboy_req:reply(200, [ {<<"content-type">>, <<"text/plain">>} ], "Hello world!", Req). -``` +---- Here is the same example but sending HTML this time. -``` erlang +[source,erlang] +---- Req2 = cowboy_req:reply(200, [ {<<"content-type">>, <<"text/html">>} ], "<html><head>Hello world!</head><body><p>Hats off!</p></body></html>", Req). -``` +---- Note that the reply is sent immediately. -:: Chunked reply +=== Chunked reply You can also stream the response body. First, you need to initiate the reply by sending the response status code. Then you can send the body in chunks of arbitrary size. -``` erlang +[source,erlang] Req2 = cowboy_req:chunked_reply(200, Req), cowboy_req:chunk("Hello...", Req2), cowboy_req:chunk("chunked...", Req2), cowboy_req:chunk("world!!", Req2). -``` You should make sure to match on `ok` as an error may be returned. @@ -84,36 +87,35 @@ While it is possible to send a chunked response without a content-type header, it is still recommended. You can set this header or any other just like for normal replies. -``` erlang +[source,erlang] +---- Req2 = cowboy_req:chunked_reply(200, [ {<<"content-type">>, <<"text/html">>} ], Req), cowboy_req:chunk("<html><head>Hello world!</head>", Req2), cowboy_req:chunk("<body><p>Hats off!</p></body></html>", Req2). -``` +---- Note that the reply and each chunk following it are sent immediately. -:: Preset response headers +=== Preset response headers You can define response headers in advance. They will be merged into the headers given in the reply call. Headers in the reply call override preset response headers which override the default Cowboy headers. -``` erlang +[source,erlang] Req2 = cowboy_req:set_resp_header(<<"allow">>, "GET", Req). -``` You can check if a response header has already been set. This will only check the response headers that you set, and not the ones Cowboy will add when actually sending the reply. -``` erlang +[source,erlang] cowboy_req:has_resp_header(<<"allow">>, Req). -``` It will return `true` if the header is defined, and `false` otherwise. @@ -121,19 +123,17 @@ otherwise. Finally, you can also delete a preset response header if needed. If you do, it will not be sent. -``` erlang +[source,erlang] Req2 = cowboy_req:delete_resp_header(<<"allow">>, Req). -``` -:: Preset response body +=== Preset response body You can set the response body in advance. Note that this body will be ignored if you then choose to send a chunked reply, or if you send a reply with an explicit body. -``` erlang +[source,erlang] Req2 = cowboy_req:set_resp_body("Hello world!", Req). -``` You can also set a fun that will be called when it is time to send the body. There are three different ways of doing @@ -144,38 +144,41 @@ you should specify it, as it will help clients determine the remaining download time and allow them to inform the user. -``` erlang +[source,erlang] +---- F = fun (Socket, Transport) -> Transport:send(Socket, "Hello world!") end, Req2 = cowboy_req:set_resp_body_fun(12, F, Req). -``` +---- If you do not know the length of the body, you should use a chunked response body fun instead. -``` erlang +[source,erlang] +---- F = fun (SendChunk) -> Body = lists:duplicate(random:uniform(1024, $a)), SendChunk(Body) end, Req2 = cowboy_req:set_resp_body_fun(chunked, F, Req). -``` +---- Finally, you can also send data on the socket directly, without knowing the length in advance. Cowboy may be forced to close the connection at the end of the response though depending on the protocol capabilities. -``` erlang +[source,erlang] +---- F = fun (Socket, Transport) -> Body = lists:duplicate(random:uniform(1024, $a)), Transport:send(Socket, Body) end, Req2 = cowboy_req:set_resp_body_fun(F, Req). -``` +---- -:: Sending files +=== Sending files You can send files directly from disk without having to read them. Cowboy will use the `sendfile` syscall when @@ -186,12 +189,13 @@ than doing it from userland. Again, it is recommended to set the size of the file if it can be known in advance. -``` erlang +[source,erlang] +---- F = fun (Socket, Transport) -> Transport:sendfile(Socket, "priv/styles.css") end, Req2 = cowboy_req:set_resp_body_fun(FileSize, F, Req). -``` +---- Please see the Ranch guide for more information about sending files. diff --git a/doc/src/guide/rest_flowcharts.ezdoc b/doc/src/guide/rest_flowcharts.asciidoc index cee9cf0..b569782 100644 --- a/doc/src/guide/rest_flowcharts.ezdoc +++ b/doc/src/guide/rest_flowcharts.asciidoc @@ -1,4 +1,5 @@ -::: REST flowcharts +[[rest_flowcharts]] +== REST flowcharts This chapter will explain the REST handler state machine through a number of different diagrams. @@ -17,11 +18,11 @@ indicate a response. Other squares may be either a callback or a question answered by Cowboy itself. Green arrows tend to indicate the default behavior if the callback is undefined. -:: Start +=== Start All requests start from here. -^"REST starting flowchart^!rest_start.png +image::rest_start.png[REST starting flowchart] A series of callbacks are called in succession to perform a general checkup of the service, the request line and @@ -48,11 +49,11 @@ This diagram is immediately followed by either the "OPTIONS method" diagram when the request method is OPTIONS, or the "Content negotiation" diagram otherwise. -:: OPTIONS method +=== OPTIONS method This diagram only applies to OPTIONS requests. -^"REST OPTIONS method flowchart^!rest_options.png +image::rest_options.png[REST OPTIONS method flowchart] The `options` callback may be used to add information about the resource, such as media types or languages @@ -64,13 +65,13 @@ If the `options` callback is not defined, Cowboy will send a response containing the list of allowed methods by default. -:: Content negotiation +=== Content negotiation This diagram applies to all request methods other than OPTIONS. It is executed right after the "Start" diagram is completed. -^"REST content negotiation flowchart^!rest_conneg.png +image::rest_conneg.png[REST content negotiation flowchart] The purpose of these steps is to determine an appropriate representation to be sent back to the client. @@ -105,14 +106,14 @@ the "PUT, POST and PATCH methods" diagram, or the "DELETE method" diagram, depending on the method. -:: GET and HEAD methods +=== GET and HEAD methods This diagram only applies to GET and HEAD requests. For a description of the `cond` step, please see the "Conditional requests" diagram. -^"REST GET/HEAD methods flowchart^!rest_get_head.png +image::rest_get_head.png[REST GET/HEAD methods flowchart] When the resource exists, and the conditional steps succeed, the resource can be retrieved. @@ -134,14 +135,14 @@ The `moved_permanently` and `moved_temporarily` callbacks must return the new location of the resource if it was in fact moved. -:: PUT, POST and PATCH methods +=== PUT, POST and PATCH methods This diagram only applies to PUT, POST and PATCH requests. For a description of the `cond` step, please see the "Conditional requests" diagram. -^"REST PUT/POST/PATCH methods flowchart^!rest_put_post_patch.png +image::rest_put_post_patch.png[REST PUT/POST/PATCH methods flowchart] When the resource exists, first the conditional steps are executed. When that succeeds, and the method is PUT, @@ -188,14 +189,14 @@ on whether a resource has been created, rather than modified, and on the availability of a location header or a body in the response. -:: DELETE method +=== DELETE method This diagram only applies to DELETE requests. For a description of the `cond` step, please see the "Conditional requests" diagram. -^"REST DELETE method flowchart^!rest_delete.png +image::rest_delete.png[REST DELETE method flowchart] When the resource exists, and the conditional steps succeed, the resource can be deleted. @@ -227,13 +228,13 @@ The `moved_permanently` and `moved_temporarily` callbacks must return the new location of the resource if it was in fact moved. -:: Conditional requests +=== Conditional requests This diagram applies to all request methods other than OPTIONS. It is executed right after the `resource_exists` callback, when the resource exists. -^"REST conditional requests flowchart^!rest_cond.png +image::rest_cond.png[REST conditional requests flowchart] A request becomes conditional when it includes either of the if-match header; the if-unmodified-since header; the diff --git a/doc/src/guide/rest_handlers.ezdoc b/doc/src/guide/rest_handlers.asciidoc index e6bb092..6bff18d 100644 --- a/doc/src/guide/rest_handlers.ezdoc +++ b/doc/src/guide/rest_handlers.asciidoc @@ -1,4 +1,5 @@ -::: REST handlers +[[rest_handlers]] +== REST handlers REST is implemented in Cowboy as a sub protocol. The request is handled as a state machine with many optional callbacks @@ -6,16 +7,17 @@ describing the resource and modifying the machine's behavior. The REST handler is the recommended way to handle HTTP requests. -:: Initialization +=== Initialization First, the `init/2` callback is called. This callback is common to all handlers. To use REST for the current request, this function must return a `cowboy_rest` tuple. -``` erlang +[source,erlang] +---- init(Req, _Opts) -> {cowboy_rest, Req, #state{}}. -``` +---- Cowboy will then switch to the REST protocol and start executing the state machine. @@ -23,7 +25,7 @@ the state machine. After reaching the end of the flowchart, the `terminate/3` callback will be called if it is defined. -:: Methods +=== Methods The REST component has code for handling the following HTTP methods: HEAD, GET, POST, PATCH, PUT, DELETE and OPTIONS. @@ -31,7 +33,7 @@ HEAD, GET, POST, PATCH, PUT, DELETE and OPTIONS. Other methods can be accepted, however they have no specific callback defined for them at this time. -:: Callbacks +=== Callbacks All callbacks are optional. Some may become mandatory depending on what other defined callbacks return. The various flowcharts @@ -53,35 +55,37 @@ In the following table, "skip" means the callback is entirely skipped if it is undefined, moving directly to the next step. Similarly, "none" means there is no default value for this callback. -|| Callback name Default value -| -| allowed_methods `[<<"GET">>, <<"HEAD">>, <<"OPTIONS">>]` -| allow_missing_post `true` -| charsets_provided skip -| content_types_accepted none -| content_types_provided `[{{<<"text">>, <<"html">>, '*'}, to_html}] ` -| delete_completed `true` -| delete_resource `false` -| expires `undefined` -| forbidden `false` -| generate_etag `undefined` -| is_authorized `true` -| is_conflict `false` -| known_methods `[<<"GET">>, <<"HEAD">>, <<"POST">>, <<"PUT">>, <<"PATCH">>, <<"DELETE">>, <<"OPTIONS">>]` -| languages_provided skip -| last_modified `undefined` -| malformed_request `false` -| moved_permanently `false` -| moved_temporarily `false` -| multiple_choices `false` -| options `ok` -| previously_existed `false` -| resource_exists `true` -| service_available `true` -| uri_too_long `false` -| valid_content_headers `true` -| valid_entity_length `true` -| variances `[]` +[cols="<,^",options="header"] +|=== +| Callback name | Default value +| allowed_methods | `[<<"GET">>, <<"HEAD">>, <<"OPTIONS">>]` +| allow_missing_post | `true` +| charsets_provided | skip +| content_types_accepted | none +| content_types_provided | `$$[{{<<"text">>, <<"html">>, '*'}, to_html}]$$` +| delete_completed | `true` +| delete_resource | `false` +| expires | `undefined` +| forbidden | `false` +| generate_etag | `undefined` +| is_authorized | `true` +| is_conflict | `false` +| known_methods | `[<<"GET">>, <<"HEAD">>, <<"POST">>, <<"PUT">>, <<"PATCH">>, <<"DELETE">>, <<"OPTIONS">>]` +| languages_provided | skip +| last_modified | `undefined` +| malformed_request | `false` +| moved_permanently | `false` +| moved_temporarily | `false` +| multiple_choices | `false` +| options | `ok` +| previously_existed | `false` +| resource_exists | `true` +| service_available | `true` +| uri_too_long | `false` +| valid_content_headers | `true` +| valid_entity_length | `true` +| variances | `[]` +|=== As you can see, Cowboy tries to move on with the request whenever possible by using well thought out default values. @@ -94,32 +98,36 @@ each function. For example, `from_html` and `to_html` indicate in the first case that we're accepting a resource given as HTML, and in the second case that we send one as HTML. -:: Meta data +=== Meta data Cowboy will set informative meta values at various points of the execution. You can retrieve them using `cowboy_req:meta/{2,3}`. The values are defined in the following table. -|| Meta key Details -| -| media_type The content-type negotiated for the response entity. -| language The language negotiated for the response entity. -| charset The charset negotiated for the response entity. +[cols="<,<",options="header"] +|=== +| Meta key | Details +| media_type | The content-type negotiated for the response entity. +| language | The language negotiated for the response entity. +| charset | The charset negotiated for the response entity. +|=== They can be used to send a proper body with the response to a request that used a method other than HEAD or GET. -:: Response headers +=== Response headers Cowboy will set response headers automatically over the execution of the REST code. They are listed in the following table. -|| Header name Details -| -| content-language Language used in the response body -| content-type Media type and charset of the response body -| etag Etag of the resource -| expires Expiration date of the resource -| last-modified Last modification date for the resource -| location Relative or absolute URI to the requested resource -| vary List of headers that may change the representation of the resource +[cols="<,<",options="header"] +|=== +| Header name | Details +| content-language | Language used in the response body +| content-type | Media type and charset of the response body +| etag | Etag of the resource +| expires | Expiration date of the resource +| last-modified | Last modification date for the resource +| location | Relative or absolute URI to the requested resource +| vary | List of headers that may change the representation of the resource +|=== diff --git a/doc/src/guide/rest_principles.ezdoc b/doc/src/guide/rest_principles.asciidoc index 1d54594..6ae2063 100644 --- a/doc/src/guide/rest_principles.ezdoc +++ b/doc/src/guide/rest_principles.asciidoc @@ -1,4 +1,5 @@ -::: REST principles +[[rest_principles]] +== REST principles This chapter will attempt to define the concepts behind REST and explain what makes a service RESTful. @@ -10,11 +11,11 @@ and POST methods. That's highly misguided at best. We will first attempt to define REST and will look at what it means in the context of HTTP and the Web. For a more in-depth explanation of REST, you can read -^"Roy T. Fielding's dissertation^http://www.ics.uci.edu/~fielding/pubs/dissertation/top.htm +http://www.ics.uci.edu/~fielding/pubs/dissertation/top.htm[Roy T. Fielding's dissertation] as it does a great job explaining where it comes from and what it achieves. -:: REST architecture +=== REST architecture REST is a *client-server* architecture. The client and the server both have a different set of concerns. The server stores and/or @@ -54,7 +55,7 @@ to extend client functionality. This is optional however because the client may not be able to download or run this code, and so a REST component cannot rely on it being executed. -:: Resources and resource identifiers +=== Resources and resource identifiers A resource is an abstract concept. In a REST system, any information that can be named may be a resource. This includes documents, images, @@ -79,7 +80,7 @@ resources map to a set of one element, for example "user Joe". Collection of resources map to a set of 0 to N elements, for example "all users". -:: Resource representations +=== Resource representations The representation of a resource is a sequence of bytes associated with metadata. @@ -111,7 +112,7 @@ type. Some media types are intended for direct rendering to the user, while others are intended for automated processing. The media type is a key component of the REST architecture. -:: Self-descriptive messages +=== Self-descriptive messages Messages must be self-descriptive. That means that the data format of a representation must always come with its media @@ -132,7 +133,7 @@ This means that you can create your own media types, like specifications for it and that both endpoints agree about it then the constraint is respected. -:: Hypermedia as the engine of application state +=== Hypermedia as the engine of application state The last constraint is generally where services that claim to be RESTful fail. Interactions with a server must be diff --git a/doc/src/guide/routing.ezdoc b/doc/src/guide/routing.asciidoc index 2482c12..6ac2ebd 100644 --- a/doc/src/guide/routing.ezdoc +++ b/doc/src/guide/routing.asciidoc @@ -1,4 +1,5 @@ -::: Routing +[[routing]] +== Routing Cowboy does nothing by default. @@ -14,42 +15,38 @@ and then try to find a matching path. Routes need to be compiled before they can be used by Cowboy. -:: Structure +=== Structure The general structure for the routes is defined as follow. -``` erlang +[source,erlang] Routes = [Host1, Host2, ... HostN]. -``` Each host contains matching rules for the host along with optional constraints, and a list of routes for the path component. -``` erlang +[source,erlang] Host1 = {HostMatch, PathsList}. Host2 = {HostMatch, Constraints, PathsList}. -``` The list of routes for the path component is defined similar to the list of hosts. -``` erlang +[source,erlang] PathsList = [Path1, Path2, ... PathN]. -``` Finally, each path contains matching rules for the path along with optional constraints, and gives us the handler module to be used along with options that will be given to it on initialization. -``` erlang +[source,erlang] Path1 = {PathMatch, Handler, Opts}. Path2 = {PathMatch, Constraints, Handler, Opts}. -``` Continue reading to learn more about the match syntax and the optional constraints. -:: Match syntax +=== Match syntax The match syntax is used to associate host names and paths with their respective handlers. @@ -64,30 +61,29 @@ Excluding special values that we will explain at the end of this section, the simplest match value is a host or a path. It can be given as either a `string()` or a `binary()`. -``` erlang +[source,erlang] +---- PathMatch1 = "/". PathMatch2 = "/path/to/resource". HostMatch1 = "cowboy.example.org". -``` +---- As you can see, all paths defined this way must start with a slash character. Note that these two paths are identical as far as routing is concerned. -``` erlang +[source,erlang] PathMatch2 = "/path/to/resource". PathMatch3 = "/path/to/resource/". -``` Hosts with and without a trailing dot are equivalent for routing. Similarly, hosts with and without a leading dot are also equivalent. -``` erlang +[source,erlang] HostMatch1 = "cowboy.example.org". HostMatch2 = "cowboy.example.org.". HostMatch3 = ".cowboy.example.org". -``` It is possible to extract segments of the host and path and to store the values in the `Req` object for later use. We call these kind of @@ -97,10 +93,9 @@ The syntax for bindings is very simple. A segment that begins with the `:` character means that what follows until the end of the segment is the name of the binding in which the segment value will be stored. -``` erlang +[source,erlang] PathMatch = "/hats/:name/prices". HostMatch = ":subdomain.example.org". -``` If these two end up matching when routing, you will end up with two bindings defined, `subdomain` and `name`, each containing the @@ -116,23 +111,20 @@ variable in Erlang. Any match against the `_` binding will succeed but the data will be discarded. This is especially useful for matching against many domain names in one go. -``` erlang +[source,erlang] HostMatch = "ninenines.:_". -``` Similarly, it is possible to have optional segments. Anything between brackets is optional. -``` erlang +[source,erlang] PathMatch = "/hats/[page/:number]". HostMatch = "[www.]ninenines.eu". -``` You can also have imbricated optional segments. -``` erlang +[source,erlang] PathMatch = "/hats/[page/[:number]]". -``` You can retrieve the rest of the host or path using `[...]`. In the case of hosts it will match anything before, in the case @@ -142,51 +134,45 @@ zero, one or many segments. You can then find the segments using `cowboy_req:host_info/1` and `cowboy_req:path_info/1` respectively. They will be represented as a list of segments. -``` erlang +[source,erlang] PathMatch = "/hats/[...]". HostMatch = "[...]ninenines.eu". -``` If a binding appears twice in the routing rules, then the match will succeed only if they share the same value. This copies the Erlang pattern matching behavior. -``` erlang +[source,erlang] PathMatch = "/hats/:name/:name". -``` This is also true when an optional segment is present. In this case the two values must be identical only if the segment is available. -``` erlang +[source,erlang] PathMatch = "/hats/:name/[:name]". -``` If a binding is defined in both the host and path, then they must also share the same value. -``` erlang +[source,erlang] PathMatch = "/:user/[...]". HostMatch = ":user.github.com". -``` Finally, there are two special match values that can be used. The first is the atom `'_'` which will match any host or path. -``` erlang +[source,erlang] PathMatch = '_'. HostMatch = '_'. -``` The second is the special host match `"*"` which will match the wildcard path, generally used alongside the `OPTIONS` method. -``` erlang +[source,erlang] HostMatch = "*". -``` -:: Constraints +=== Constraints After the matching has completed, the resulting bindings can be tested against a set of constraints. Constraints are only tested when the @@ -200,9 +186,9 @@ one or more constraints. While the router accepts the same format, it will skip fields with no constraints and will also ignore default values, if any. -Read more about ^constraints^. +Read more about xref:constraints[constraints]. -:: Compilation +=== Compilation The structure defined in this chapter needs to be compiled before it is passed to Cowboy. This allows Cowboy to efficiently lookup the correct @@ -210,7 +196,8 @@ handler to run instead of having to parse the routes repeatedly. This can be done with a simple call to `cowboy_router:compile/1`. -``` erlang +[source,erlang] +---- Dispatch = cowboy_router:compile([ %% {HostMatch, list({PathMatch, Handler, Opts})} {'_', [{'_', my_handler, []}]} @@ -220,20 +207,18 @@ cowboy:start_http(my_http_listener, 100, [{port, 8080}], [{env, [{dispatch, Dispatch}]}] ). -``` +---- Note that this function will return `{error, badarg}` if the structure given is incorrect. -:: Live update +=== Live update You can use the `cowboy:set_env/3` function for updating the dispatch list used by routing. This will apply to all new connections accepted by the listener. -``` erlang -cowboy:set_env(my_http_listener, dispatch, - cowboy_router:compile(Dispatch)). -``` +[source,erlang] +cowboy:set_env(my_http_listener, dispatch, cowboy_router:compile(Dispatch)). Note that you need to compile the routes before updating. diff --git a/doc/src/guide/static_files.ezdoc b/doc/src/guide/static_files.asciidoc index 5a289d0..39197a8 100644 --- a/doc/src/guide/static_files.ezdoc +++ b/doc/src/guide/static_files.asciidoc @@ -1,4 +1,5 @@ -::: Static files +[[static_files]] +== Static files Cowboy comes with a special handler built as a REST handler and designed specifically for serving static files. It is @@ -20,30 +21,28 @@ client-side caching. To use the static file handler, simply add routes for it with the appropriate options. -:: Serve one file +=== Serve one file You can use the static handler to serve one specific file from an application's private directory. This is particularly -useful to serve an `index.html` file when the client requests +useful to serve an 'index.html' file when the client requests the `/` path, for example. The path configured is relative to the given application's private directory. -The following rule will serve the file `static/index.html` +The following rule will serve the file 'static/index.html' from the application `my_app`'s priv directory whenever the path `/` is accessed. -``` erlang +[source,erlang] {"/", cowboy_static, {priv_file, my_app, "static/index.html"}} -``` You can also specify the absolute path to a file, or the path to the file relative to the current directory. -``` erlang +[source,erlang] {"/", cowboy_static, {file, "/var/www/index.html"}} -``` -:: Serve all files from a directory +=== Serve all files from a directory You can also use the static handler to serve all files that can be found in the configured directory. The handler will @@ -59,18 +58,16 @@ The following rule will serve any file found in the application `my_app`'s priv directory inside the `static/assets` folder whenever the requested path begins with `/assets/`. -``` erlang +[source,erlang] {"/assets/[...]", cowboy_static, {priv_dir, my_app, "static/assets"}} -``` You can also specify the absolute path to the directory or set it relative to the current directory. -``` erlang +[source,erlang] {"/assets/[...]", cowboy_static, {dir, "/var/www/assets"}} -``` -:: Customize the mimetype detection +=== Customize the mimetype detection By default, Cowboy will attempt to recognize the mimetype of your static files by looking at the extension. @@ -91,10 +88,11 @@ To use the default function, you should not have to configure anything, as it is the default. If you insist, though, the following will do the job. -``` erlang +[source,erlang] +---- {"/assets/[...]", cowboy_static, {priv_dir, my_app, "static/assets", [{mimetypes, cow_mimetypes, web}]}} -``` +---- As you can see, there is an optional field that may contain a list of less used options, like mimetypes or etag. All option @@ -103,19 +101,21 @@ types have this optional field. To use the function that will detect almost any mimetype, the following configuration will do. -``` erlang +[source,erlang] +---- {"/assets/[...]", cowboy_static, {priv_dir, my_app, "static/assets", [{mimetypes, cow_mimetypes, all}]}} -``` +---- You probably noticed the pattern by now. The configuration expects a module and a function name, so you can use any of your own functions instead. -``` erlang +[source,erlang] +---- {"/assets/[...]", cowboy_static, {priv_dir, my_app, "static/assets", [{mimetypes, Module, Function}]}} -``` +---- The function that performs the mimetype detection receives a single argument that is the path to the file on disk. It @@ -133,12 +133,13 @@ Finally, the mimetype can be hard-coded for all files. This is especially useful in combination with the `file` and `priv_file` options as it avoids needless computation. -``` erlang +[source,erlang] +---- {"/", cowboy_static, {priv_file, my_app, "static/index.html", [{mimetypes, {<<"text">>, <<"html">>, []}}]}} -``` +---- -:: Generate an etag +=== Generate an etag By default, the static handler will generate an etag header value based on the size and modified time. This solution @@ -149,10 +150,11 @@ different etag on each server. You can however change the way the etag is calculated. -``` erlang +[source,erlang] +---- {"/assets/[...]", cowboy_static, {priv_dir, my_app, "static/assets", [{etag, Module, Function}]}} -``` +---- This function will receive three arguments: the path to the file on disk, the size of the file and the last modification @@ -162,7 +164,8 @@ all your servers. You can also completely disable etag handling. -``` erlang +[source,erlang] +---- {"/assets/[...]", cowboy_static, {priv_dir, my_app, "static/assets", [{etag, false}]}} -``` +---- diff --git a/doc/src/guide/sub_protocols.ezdoc b/doc/src/guide/sub_protocols.asciidoc index 54e57aa..63fd52b 100644 --- a/doc/src/guide/sub_protocols.ezdoc +++ b/doc/src/guide/sub_protocols.asciidoc @@ -1,4 +1,5 @@ -::: Sub protocols +[[sub_protocols]] +== Sub protocols Sub protocols are used for creating new types of handlers that provide extra functionality in a reusable way. Cowboy uses this @@ -7,16 +8,17 @@ mechanism to provide its loop, REST and Websocket handlers. This chapter will explain how to create your own sub protocols and handler types. -:: Usage +=== Usage To switch to a sub protocol, the `init/2` callback must return the name of the sub protocol module. Everything past this point is handled by the sub protocol. -``` erlang +[source,erlang] +---- init(Req, _Opts) -> {cowboy_websocket, Req, #state{}}. -``` +---- The return value may also have a `Timeout` value and/or the atom `hibernate`. These options are useful for long living @@ -27,15 +29,16 @@ The following snippet switches to the `my_protocol` sub protocol, sets the timeout value to 5 seconds and enables hibernation: -``` erlang +[source,erlang] +---- init(Req, _Opts) -> {my_protocol, Req, #state{}, 5000, hibernate}. -``` +---- If a sub protocol does not make use of these options, it should crash if it receives anything other than the default values. -:: Upgrade +=== Upgrade After the `init/2` function returns, Cowboy will then call the `upgrade/6` function. This is the only callback defined by the @@ -51,10 +54,11 @@ The upgrade callback receives the Req object, the middleware environment, the handler and its options, and the aforementioned timeout and hibernate values. -``` erlang +[source,erlang] +---- upgrade(Req, Env, Handler, HandlerOpts, Timeout, Hibernate) -> %% Sub protocol code here. -``` +---- This callback is expected to behave like a middleware and to return an updated environment and Req object. diff --git a/doc/src/guide/ws_handlers.ezdoc b/doc/src/guide/ws_handlers.asciidoc index a0cfc29..9ddddf4 100644 --- a/doc/src/guide/ws_handlers.ezdoc +++ b/doc/src/guide/ws_handlers.asciidoc @@ -1,4 +1,5 @@ -::: Handling Websocket connections +[[ws_handlers]] +== Handling Websocket connections A special handler is required for handling Websocket connections. Websocket handlers allow you to initialize the connection, @@ -9,16 +10,17 @@ Websocket handlers essentially act as a bridge between the client and the Erlang system. They will typically do little more than socket communication and decoding/encoding of frames. -:: Initialization +=== Initialization First, the `init/2` callback is called. This callback is common to all handlers. To establish a Websocket connection, this function must return a `ws` tuple. -``` erlang +[source,erlang] +---- init(Req, _Opts) -> {cowboy_websocket, Req, #state{}}. -``` +---- Upon receiving this tuple, Cowboy will switch to the code that handles Websocket connections and perform the handshake @@ -30,7 +32,8 @@ handler *must* select one of these subprotocol and send it back to the client, otherwise the client might decide to close the connection, assuming no correct subprotocol was found. -``` erlang +[source,erlang] +---- init(Req, _Opts) -> case cowboy_req:parse_header(<<"sec-websocket-protocol">>, Req) of undefined -> @@ -45,7 +48,7 @@ init(Req, _Opts) -> {stop, Req, undefined} end end. -``` +---- It is not recommended to wait too long inside the `init/2` function. Any extra initialization may be done after returning by @@ -57,7 +60,8 @@ It is also very easy to ensure that this message arrives before any message from other processes by sending it before registering or enabling timers. -``` erlang +[source,erlang] +---- init(Req, _Opts) -> self() ! post_init, %% Register process here... @@ -66,9 +70,9 @@ init(Req, _Opts) -> websocket_info(post_init, Req, State) -> %% Perform post_init initialization here... {ok, Req, State}. -``` +---- -:: Handling frames from the client +=== Handling frames from the client Cowboy will call `websocket_handle/3` whenever a text, binary, ping or pong frame arrives from the client. Note that in the @@ -81,14 +85,15 @@ or just continue without sending anything. The following snippet echoes back any text frame received and ignores all others. -``` erlang +[source,erlang] +---- websocket_handle(Frame = {text, _}, Req, State) -> {reply, Frame, Req, State}; websocket_handle(_Frame, Req, State) -> {ok, Req, State}. -``` +---- -:: Handling Erlang messages +=== Handling Erlang messages Cowboy will call `websocket_info/3` whenever an Erlang message arrives. @@ -99,14 +104,15 @@ or just continue without sending anything. The following snippet forwards any `log` message to the socket and ignores all others. -``` erlang +[source,erlang] +---- websocket_info({log, Text}, Req, State) -> {reply, {text, Text}, Req, State}; websocket_info(_Info, Req, State) -> {ok, Req, State}. -``` +---- -:: Sending frames to the socket +=== Sending frames to the socket Cowboy allows sending either a single frame or a list of frames to the socket, in which case the frames are sent @@ -116,7 +122,8 @@ pong or close frames. The following example sends three frames using a single `reply` tuple. -``` erlang +[source,erlang] +---- websocket_info(hello_world, Req, State) -> {reply, [ {text, "Hello"}, @@ -124,7 +131,7 @@ websocket_info(hello_world, Req, State) -> {binary, <<0:8000>>} ], Req, State}; %% More websocket_info/3 clauses here... -``` +---- Note that the payload for text and binary frames is of type `iodata()`, meaning it can be either a `binary()` or an @@ -137,7 +144,7 @@ be received will not be processed. Also note that when replying a list of frames that includes close, any frame found after the close frame will not be sent. -:: Ping and timeout +=== Ping and timeout The biggest performance improvement you can do when dealing with a huge number of Websocket connections is to reduce the @@ -160,15 +167,16 @@ leave the process alive forever. A good timeout value is 60 seconds. -``` erlang +[source,erlang] +---- init(Req, _Opts) -> {cowboy_websocket, Req, #state{}, 60000}. -``` +---- This value cannot be changed once it is set. It defaults to `infinity`. -:: Hibernate +=== Hibernate Most tuples returned from handler callbacks can include an extra value `hibernate`. After doing any necessary operations @@ -180,9 +188,9 @@ handle much traffic. It is a good idea to hibernate all connections by default and investigate only when you start noticing increased CPU usage. -:: Supporting older browsers +=== Supporting older browsers Unfortunately Websocket is a relatively recent technology, which means that not all browsers support it. A library like -^"Bullet^https://github.com/extend/bullet^ can be used to +https://github.com/ninenines/bullet[Bullet] can be used to emulate Websocket connections on older browsers. diff --git a/doc/src/guide/ws_protocol.ezdoc b/doc/src/guide/ws_protocol.asciidoc index d283ae3..67b2cdf 100644 --- a/doc/src/guide/ws_protocol.ezdoc +++ b/doc/src/guide/ws_protocol.asciidoc @@ -1,9 +1,10 @@ -::: The Websocket protocol +[[ws_protocol]] +== The Websocket protocol This chapter explains what Websocket is and why it is a vital component of soft realtime Web applications. -:: Description +=== Description Websocket is an extension to HTTP that emulates plain TCP connections between the client, typically a Web browser, @@ -22,7 +23,7 @@ and all drafts that were previously implemented by browsers, excluding the initial flawed draft sometimes known as "version 0". -:: Implementation +=== Implementation Cowboy implements Websocket as a protocol upgrade. Once the upgrade is performed from the `init/2` callback, Cowboy diff --git a/doc/src/manual/cowboy.asciidoc b/doc/src/manual/cowboy.asciidoc new file mode 100644 index 0000000..cd83b3d --- /dev/null +++ b/doc/src/manual/cowboy.asciidoc @@ -0,0 +1,98 @@ += cowboy(3) + +== Name + +cowboy - HTTP server + +== Description + +The `cowboy` module provides convenience functions for +manipulating Ranch listeners. + +== Types + +=== fields() = [Field] + +[source,erlang] +---- +Field = atom() + | {atom(), cowboy_constraints:constraint() | [cowboy_constraints:constraint()]} + | {atom(), cowboy_constraints:constraint() | [cowboy_constraints:constraint()], any()}] +---- + +Fields for match operations. Constraint(s) and default value are optional. + +=== http_headers() = [{binary(), iodata()}] + +HTTP headers as a list of key/values. + +=== http_status() = non_neg_integer() | binary() + +HTTP status. + +A binary status can be used to set a custom message. + +=== http_version() = \'HTTP/1.1' | \'HTTP/1.0' + +HTTP version. + +=== `onresponse_fun() = fun((http_status(), http_headers(), iodata(), cowboy_req:req()) -> cowboy_req:req())` + +Fun called immediately before sending the response. + +It can perform any operation on the Req object, including +reading the request body or replying. If a reply is sent, it +overrides the reply initially sent. The callback will not be +called again for the new reply. + +== Exports + +=== start_http(Ref, NbAcceptors, TransOpts, ProtoOpts) -> {ok, pid()} + +Ref = ranch:ref():: Listener name. +NbAcceptors = non_neg_integer():: Number of acceptor processes. +TransOpts = ranch_tcp:opts():: TCP transport options. +ProtoOpts = cowboy_protocol:opts():: HTTP protocol options. + +Start listening for HTTP connections. Returns the pid for this +listener's supervisor. + +=== start_https(Ref, NbAcceptors, TransOpts, ProtoOpts) -> {ok, pid()} + +Ref = ranch:ref():: Listener name. +NbAcceptors = non_neg_integer():: Number of acceptor processes. +TransOpts = ranch_ssl:opts():: SSL transport options. +ProtoOpts = cowboy_protocol:opts():: HTTP protocol options. + +Start listening for HTTPS connections. Returns the pid for this +listener's supervisor. + +=== start_spdy(Ref, NbAcceptors, TransOpts, ProtoOpts) -> {ok, pid()} + +Ref = ranch:ref():: Listener name. +NbAcceptors = non_neg_integer():: Number of acceptor processes. +TransOpts = ranch_ssl:opts():: SSL transport options. +ProtoOpts = cowboy_spdy:opts():: SPDY protocol options. + +Start listening for SPDY connections. Returns the pid for this +listener's supervisor. + +=== stop_listener(Ref) -> ok | {error, not_found} + +Ref = ranch:ref():: Listener name. + +Stop a previously started listener. + +=== set_env(Ref, Name, Value) -> ok + +Ref = ranch:ref():: Listener name. +Name = atom():: Name of environment value. +Value = any():: Environment value. + +Set or update an environment value for an already running listener. +This will take effect on all subsequent connections. + +== See also + +The http://ninenines.eu/docs/en/ranch/HEAD/guide[Ranch guide] +provides detailed information about how listeners work. diff --git a/doc/src/manual/cowboy.ezdoc b/doc/src/manual/cowboy.ezdoc deleted file mode 100644 index c26ed37..0000000 --- a/doc/src/manual/cowboy.ezdoc +++ /dev/null @@ -1,98 +0,0 @@ -::: cowboy - -The `cowboy` module provides convenience functions for -manipulating Ranch listeners. - -:: Types - -: fields() = [atom() - | {atom(), cowboy_constraints:constraint() | [cowboy_constraints:constraint()]} - | {atom(), cowboy_constraints:constraint() | [cowboy_constraints:constraint()], any()}] - -Fields for match operations. Constraint(s) and default value are optional. - -: http_headers() = [{binary(), iodata()}] - -HTTP headers as a list of key/values. - -: http_status() = non_neg_integer() | binary() - -HTTP status. - -A binary status can be used to set a custom message. - -: http_version() = 'HTTP/1.1' | 'HTTP/1.0' - -HTTP version. - -: onresponse_fun() = fun((http_status(), http_headers(), - iodata(), cowboy_req:req()) -> cowboy_req:req()) - -Fun called immediately before sending the response. - -It can perform any operation on the Req object, including -reading the request body or replying. If a reply is sent, it -overrides the reply initially sent. The callback will not be -called again for the new reply. - -:: Exports - -: start_http(Ref, NbAcceptors, TransOpts, ProtoOpts) -> {ok, pid()} - -Types: - -* Ref = ranch:ref() -* NbAcceptors = non_neg_integer() -* TransOpts = ranch_tcp:opts() -* ProtoOpts = cowboy_protocol:opts() - -Start listening for HTTP connections. Returns the pid for this -listener's supervisor. - -: start_https(Ref, NbAcceptors, TransOpts, ProtoOpts) -> {ok, pid()} - -Types: - -* Ref = ranch:ref() -* NbAcceptors = non_neg_integer() -* TransOpts = ranch_ssl:opts() -* ProtoOpts = cowboy_protocol:opts() - -Start listening for HTTPS connections. Returns the pid for this -listener's supervisor. - -: start_spdy(Ref, NbAcceptors, TransOpts, ProtoOpts) -> {ok, pid()} - -Types: - -* Ref = ranch:ref() -* NbAcceptors = non_neg_integer() -* TransOpts = ranch_ssl:opts() -* ProtoOpts = cowboy_spdy:opts() - -Start listening for SPDY connections. Returns the pid for this -listener's supervisor. - -: stop_listener(Ref) -> ok | {error, not_found} - -Types: - -* Ref = ranch:ref() - -Stop a previously started listener. - -: set_env(Ref, Name, Value) -> ok - -Types: - -* Ref = ranch:ref() -* Name = atom() -* Value = any() - -Set or update an environment value for an already running listener. -This will take effect on all subsequent connections. - -:: See also - -The ^"Ranch guide^http://ninenines.eu/docs/en/ranch/HEAD/guide -provides detailed information about how listeners work. diff --git a/doc/src/manual/cowboy_app.ezdoc b/doc/src/manual/cowboy_app.asciidoc index 2e2b877..2213bd1 100644 --- a/doc/src/manual/cowboy_app.ezdoc +++ b/doc/src/manual/cowboy_app.asciidoc @@ -1,8 +1,10 @@ -::: The Cowboy Application += cowboy(7) -Small, fast, modular HTTP server. +== Name -:: Dependencies +cowboy - Small, fast, modular HTTP server. + +== Dependencies The `cowboy` application uses the Erlang applications `ranch` for listening and accepting TCP connections, `crypto` for @@ -17,7 +19,7 @@ The `cowboy` application also uses the Erlang applications `asn1`, `public_key` and `ssl` when listening for HTTPS connections. These are started automatically if they weren't before. -:: Environment +== Environment The `cowboy` application does not define any application environment configuration parameters. diff --git a/doc/src/manual/cowboy_handler.ezdoc b/doc/src/manual/cowboy_handler.asciidoc index 81615c2..fbbe761 100644 --- a/doc/src/manual/cowboy_handler.ezdoc +++ b/doc/src/manual/cowboy_handler.asciidoc @@ -1,4 +1,10 @@ -::: cowboy_handler += cowboy_handler(3) + +== Name + +cowboy_handler - handler middleware and behaviour + +== Description The `cowboy_handler` middleware executes the handler passed through the environment values `handler` and `handler_opts`, @@ -8,51 +14,42 @@ handled and received a response. Environment input: -* handler = module() -* handler_opts = any() +handler = module():: Handler to be executed. +handler_opts = any():: Options to be passed to the handler. Environment output: -* result = ok +result = ok:: Result of the request. This module also defines the `cowboy_handler` behaviour that defines the basic interface for handlers. All Cowboy handlers implement at least the `init/2` callback, and may implement the `terminate/3` callback optionally. -:: Terminate reasons +== Terminate reasons The following values may be received as the terminate reason in the optional `terminate/3` callback. Different handler types may define additional terminate reasons. -: normal - -The connection was closed normally. +normal:: + The connection was closed normally. -: {crash, Class, Reason} +{crash, Class, Reason}:: + A crash occurred in the handler. `Class` and `Reason` can be + used to obtain more information about the crash. The function + `erlang:get_stacktrace/0` can also be called to obtain the + stacktrace of the process when the crash occurred. -A crash occurred in the handler. `Class` and `Reason` can be -used to obtain more information about the crash. The function -`erlang:get_stacktrace/0` can also be called to obtain the -stacktrace of the process when the crash occurred. +== Callbacks -:: Callbacks +=== init(Req, Opts) -> {ok, Req, State} | {Module, Req, State} | {Module, Req, State, hibernate | Timeout} | {Module, Req, State, Timeout, hibernate} -: init(Req, Opts) - -> {ok, Req, State} - | {Module, Req, State} - | {Module, Req, State, hibernate} - | {Module, Req, State, Timeout} - | {Module, Req, State, Timeout, hibernate} - -Types: - -* Req = cowboy_req:req() -* Opts = any() -* State = any() -* Module = module() -* Timeout = timeout() +Req = cowboy_req:req():: The Req object. +Opts = any():: Handler options. +State = any():: Handler state. +Module = module():: Module of the sub-protocol to use. +Timeout = timeout():: Timeout passed to the sub-protocol, when applicable. Process the request. @@ -68,13 +65,11 @@ A crash in this callback will result in `terminate/3` being called if it is defined, with the `State` argument set to the value of `Opts` originally given to the `init/2` callback. -: terminate(Reason, Req, State) -> ok +=== terminate(Reason, Req, State) -> ok -Types: - -* Reason = any() -* Req = cowboy_req:req() -* State = any() +Reason = any():: Reason for termination. +Req = cowboy_req:req():: The Req object. +State = any():: Handler state. Perform any necessary cleanup of the state. @@ -88,16 +83,14 @@ A crash in this callback or an invalid return value will result in the closing of the connection and the termination of the process. -:: Exports - -: terminate(Reason, Req, State, Handler) -> ok +== Exports -Types: +=== terminate(Reason, Req, State, Handler) -> ok -* Reason = any() -* Req = cowboy_req:req() -* State = any() -* Handler = module() +Reason = any():: Reason for termination. +Req = cowboy_req:req():: The Req object. +State = any():: Handler state. +Handler = module():: Handler module. Call the optional `terminate/3` callback if it exists. diff --git a/doc/src/manual/cowboy_loop.asciidoc b/doc/src/manual/cowboy_loop.asciidoc new file mode 100644 index 0000000..eb17b15 --- /dev/null +++ b/doc/src/manual/cowboy_loop.asciidoc @@ -0,0 +1,86 @@ += cowboy_loop(3) + +== Name + +cowboy_loop - loop handlers + +== Description + +The `cowboy_loop` module implements a handler interface for +long running HTTP connections. It is the recommended interface +for long polling and server-sent events, amongst others. + +This module is a sub protocol that defines three callbacks to +be implemented by handlers. The `init/2` and `terminate/3` +callbacks are common to all handler types and are documented +in the manual for the link:cowboy_handler.asciidoc[cowboy_handler] module. + +The `info/3` callback is specific to loop handlers and will be +called as many times as necessary until a reply is sent. + +It is highly recommended to return a timeout value from the +`init/2` callback to ensure that the process is terminated +when no data has been received during that timespan. The +default timeout is `infinity`, which should only be used if +you have alternate means of ending inactive connections. + +== Terminate reasons + +The following values may be received as the terminate reason +in the optional `terminate/3` callback. + +normal:: + The connection was closed normally before switching to the + loop sub protocol. This typically happens if an `ok` tuple is + returned from the `init/2` callback. + +stop:: + The handler requested to close the connection by returning + a `stop` tuple. + +timeout:: + The connection has been closed due to inactivity. The timeout + value can be configured from `init/2`. The response sent when + this happens is a `204 No Content`. + +{crash, Class, Reason}:: + A crash occurred in the handler. `Class` and `Reason` can be + used to obtain more information about the crash. The function + `erlang:get_stacktrace/0` can also be called to obtain the + stacktrace of the process when the crash occurred. + +{error, overflow}:: + The connection is being closed and the process terminated + because the buffer Cowboy uses to keep data sent by the + client has reached its maximum. The buffer size can be + configured through the environment value `loop_max_buffer` + and defaults to 5000 bytes. + + + If the long running request comes with a body it is recommended + to process this body before switching to the loop sub protocol. + +{error, closed}:: + The socket has been closed brutally without a close frame being + received first. + +{error, Reason}:: + A socket error ocurred. + +== Callbacks + +=== info(Info, Req, State) -> {ok, Req, State} | {ok, Req, State, hibernate} | {stop, Req, State} + +Info = any():: Message received by the process. +Req = cowboy_req:req():: The Req object. +State = any():: Handler state. + +Handle the Erlang message received. + +This function will be called every time an Erlang message +has been received. The message can be any Erlang term. + +The `stop` return value can be used to stop the receive loop, +typically because a response has been sent. + +The `hibernate` option will hibernate the process until +it receives another message. diff --git a/doc/src/manual/cowboy_loop.ezdoc b/doc/src/manual/cowboy_loop.ezdoc deleted file mode 100644 index 79b96f9..0000000 --- a/doc/src/manual/cowboy_loop.ezdoc +++ /dev/null @@ -1,92 +0,0 @@ -::: cowboy_loop - -The `cowboy_loop` module implements a handler interface for -long running HTTP connections. It is the recommended interface -for long polling and server-sent events, amongst others. - -This module is a sub protocol that defines three callbacks to -be implemented by handlers. The `init/2` and `terminate/3` -callbacks are common to all handler types and are documented -in the manual for the ^cowboy_handler module. - -The `info/3` callback is specific to loop handlers and will be -called as many times as necessary until a reply is sent. - -It is highly recommended to return a timeout value from the -`init/2` callback to ensure that the process is terminated -when no data has been received during that timespan. The -default timeout is `infinity`, which should only be used if -you have alternate means of ending inactive connections. - -:: Terminate reasons - -The following values may be received as the terminate reason -in the optional `terminate/3` callback. - -: normal - -The connection was closed normally before switching to the -loop sub protocol. This typically happens if an `ok` tuple is -returned from the `init/2` callback. - -: stop - -The handler requested to close the connection by returning -a `stop` tuple. - -: timeout - -The connection has been closed due to inactivity. The timeout -value can be configured from `init/2`. The response sent when -this happens is a `204 No Content`. - -: {crash, Class, Reason} - -A crash occurred in the handler. `Class` and `Reason` can be -used to obtain more information about the crash. The function -`erlang:get_stacktrace/0` can also be called to obtain the -stacktrace of the process when the crash occurred. - -: {error, overflow} - -The connection is being closed and the process terminated -because the buffer Cowboy uses to keep data sent by the -client has reached its maximum. The buffer size can be -configured through the environment value `loop_max_buffer` -and defaults to 5000 bytes. - -If the long running request comes with a body it is recommended -to process this body before switching to the loop sub protocol. - -: {error, closed} - -The socket has been closed brutally without a close frame being -received first. - -: {error, Reason} - -A socket error ocurred. - -:: Callbacks - -: info(Info, Req, State) - -> {ok, Req, State} - | {ok, Req, State, hibernate} - | {stop, Req, State} - -Types: - -* Info = any() -* Req = cowboy_req:req() -* State = any() - -Handle the Erlang message received. - -This function will be called every time an Erlang message -has been received. The message can be any Erlang term. - -The `stop` return value can be used to stop the receive loop, -typically because a response has been sent. - -The `hibernate` option will hibernate the process until -it receives another message. diff --git a/doc/src/manual/cowboy_middleware.ezdoc b/doc/src/manual/cowboy_middleware.asciidoc index dacaf6c..87cd5d2 100644 --- a/doc/src/manual/cowboy_middleware.ezdoc +++ b/doc/src/manual/cowboy_middleware.asciidoc @@ -1,4 +1,10 @@ -::: cowboy_middleware += cowboy_middleware(3) + +== Name + +cowboy_middleware - behaviour for middlewares + +== Description The `cowboy_middleware` behaviour defines the interface used by Cowboy middleware modules. @@ -6,9 +12,9 @@ by Cowboy middleware modules. Middlewares process the request sequentially in the order they are configured. -:: Types +== Types -: env() = [{atom(), any()}] +=== env() = [{atom(), any()}] The environment variable. @@ -16,20 +22,15 @@ One is created for every request. It is passed to each middleware module executed and subsequently returned, optionally with its contents modified. -:: Callbacks - -: execute(Req, Env) - -> {ok, Req, Env} - | {suspend, Module, Function, Args} - | {stop, Req} +== Callbacks -Types: +=== execute(Req, Env) -> {ok, Req, Env} | {suspend, Module, Function, Args} | {stop, Req} -* Req = cowboy_req:req() -* Env = env() -* Module = module() -* Function = atom() -* Args = [any()] +Req = cowboy_req:req():: The Req object. +Env = env():: The request environment. +Module = module():: MFA to call when resuming the process. +Function = atom():: MFA to call when resuming the process. +Args = [any()]:: MFA to call when resuming the process. Execute the middleware. diff --git a/doc/src/manual/cowboy_protocol.asciidoc b/doc/src/manual/cowboy_protocol.asciidoc new file mode 100644 index 0000000..e1e7501 --- /dev/null +++ b/doc/src/manual/cowboy_protocol.asciidoc @@ -0,0 +1,75 @@ += cowboy_protocol(3) + +== Name + +cowboy_protocol - HTTP protocol + +== Description + +The `cowboy_protocol` module implements HTTP/1.1 and HTTP/1.0 +as a Ranch protocol. + +== Types + +=== opts() = [Option] + +[source,erlang] +---- +Option = {compress, boolean()} + | {env, cowboy_middleware:env()} + | {max_empty_lines, non_neg_integer()} + | {max_header_name_length, non_neg_integer()} + | {max_header_value_length, non_neg_integer()} + | {max_headers, non_neg_integer()} + | {max_keepalive, non_neg_integer()} + | {max_request_line_length, non_neg_integer()} + | {middlewares, [module()]} + | {onresponse, cowboy:onresponse_fun()} + | {timeout, timeout()} +---- + +Configuration for the HTTP protocol handler. + +This configuration is passed to Cowboy when starting listeners +using `cowboy:start_http/4` or `cowboy:start_https/4` functions. + +It can be updated without restarting listeners using the +Ranch functions `ranch:get_protocol_options/1` and +`ranch:set_protocol_options/2`. + +=== Option descriptions + +The default value is given next to the option name. + +compress (false):: + When enabled, Cowboy will attempt to compress the response body. + +env ([{listener, Ref}]):: + Initial middleware environment. + +max_empty_lines (5):: + Maximum number of empty lines before a request. + +max_header_name_length (64):: + Maximum length of header names. + +max_header_value_length (4096):: + Maximum length of header values. + +max_headers (100):: + Maximum number of headers allowed per request. + +max_keepalive (100):: + Maximum number of requests allowed per connection. + +max_request_line_length (4096):: + Maximum length of the request line. + +middlewares ([cowboy_router, cowboy_handler]):: + List of middlewares to execute for every requests. + +onresponse (undefined):: + Fun called every time a response is sent. + +timeout (5000):: + Time in ms with no requests before Cowboy closes the connection. diff --git a/doc/src/manual/cowboy_protocol.ezdoc b/doc/src/manual/cowboy_protocol.ezdoc deleted file mode 100644 index 1d65a5c..0000000 --- a/doc/src/manual/cowboy_protocol.ezdoc +++ /dev/null @@ -1,75 +0,0 @@ -::: cowboy_protocol - -The `cowboy_protocol` module implements HTTP/1.1 and HTTP/1.0 -as a Ranch protocol. - -:: Types - -: opts() = [{compress, boolean()} - | {env, cowboy_middleware:env()} - | {max_empty_lines, non_neg_integer()} - | {max_header_name_length, non_neg_integer()} - | {max_header_value_length, non_neg_integer()} - | {max_headers, non_neg_integer()} - | {max_keepalive, non_neg_integer()} - | {max_request_line_length, non_neg_integer()} - | {middlewares, [module()]} - | {onresponse, cowboy:onresponse_fun()} - | {timeout, timeout()}] - -Configuration for the HTTP protocol handler. - -This configuration is passed to Cowboy when starting listeners -using `cowboy:start_http/4` or `cowboy:start_https/4` functions. - -It can be updated without restarting listeners using the -Ranch functions `ranch:get_protocol_options/1` and -`ranch:set_protocol_options/2`. - -:: Option descriptions - -The default value is given next to the option name. - -: compress (false) - -When enabled, Cowboy will attempt to compress the response body. - -: env ([{listener, Ref}]) - -Initial middleware environment. - -: max_empty_lines (5) - -Maximum number of empty lines before a request. - -: max_header_name_length (64) - -Maximum length of header names. - -: max_header_value_length (4096) - -Maximum length of header values. - -: max_headers (100) - -Maximum number of headers allowed per request. - -: max_keepalive (100) - -Maximum number of requests allowed per connection. - -: max_request_line_length (4096) - -Maximum length of the request line. - -: middlewares ([cowboy_router, cowboy_handler]) - -List of middlewares to execute for every requests. - -: onresponse (undefined) - -Fun called every time a response is sent. - -: timeout (5000) - -Time in ms with no requests before Cowboy closes the connection. diff --git a/doc/src/manual/cowboy_req.ezdoc b/doc/src/manual/cowboy_req.asciidoc index 9b73886..558592b 100644 --- a/doc/src/manual/cowboy_req.ezdoc +++ b/doc/src/manual/cowboy_req.asciidoc @@ -1,4 +1,10 @@ -::: cowboy_req += cowboy_req(3) + +== Name + +cowboy_req - HTTP request and response + +== Description The `cowboy_req` module provides functions to access, manipulate and respond to requests. @@ -24,41 +30,54 @@ It is highly discouraged to pass the Req object to another process. Doing so and calling `cowboy_req` functions from it leads to undefined behavior. -:: Types +== Types + +=== body_opts() = [Option] -: body_opts() = [{continue, boolean()} +[source,erlang] +---- +Option = {continue, boolean()} | {length, non_neg_integer()} | {read_length, non_neg_integer()} | {read_timeout, timeout()} | {transfer_decode, transfer_decode_fun(), any()} - | {content_decode, content_decode_fun()}] + | {content_decode, content_decode_fun()} +---- Request body reading options. -: cookie_opts() = [{max_age, non_neg_integer()} - | {domain, binary()} | {path, binary()} - | {secure, boolean()} | {http_only, boolean()}] +=== cookie_opts() = [Option] + +[source,erlang] +---- +Option = {max_age, non_neg_integer()} + | {domain, binary()} + | {path, binary()} + | {secure, boolean()} + | {http_only, boolean()} +---- Cookie options. -: req() - opaque to the user +=== req() - opaque to the user The Req object. All functions in this module receive a `Req` as argument, -and most of them return a new object labelled `Req2` in +and some of them return a new object labelled `Req2` in the function descriptions below. -:: Request related exports +== Request related exports + +=== binding(Name, Req) -> binding(Name, Req, undefined) -: binding(Name, Req) -> binding(Name, Req, undefined) -: binding(Name, Req, Default) -> Value +Alias of `cowboy_req:binding/3`. -Types: +=== binding(Name, Req, Default) -> Value -* Name = atom() -* Default = any() -* Value = any() | Default +Name = atom():: Binding name. +Default = any():: Default value. +Value = any() | Default:: Binding value. Return the value for the given binding. @@ -66,12 +85,10 @@ By default the value is a binary, however constraints may change the type of this value (for example automatically converting numbers to integer). -: bindings(Req) -> [{Name, Value}] - -Types: +=== bindings(Req) -> [{Name, Value}] -* Name = atom() -* Value = any() +Name = atom():: Binding name. +Value = any():: Binding value. Return all bindings. @@ -79,61 +96,52 @@ By default the value is a binary, however constraints may change the type of this value (for example automatically converting numbers to integer). -: header(Name, Req) -> header(Name, Req, undefined) -: header(Name, Req, Default) -> Value +=== header(Name, Req) -> header(Name, Req, undefined) -Types: +Alias of `cowboy_req:header/3`. -* Name = binary() -* Default = any() -* Value = binary() | Default +=== header(Name, Req, Default) -> Value + +Name = binary():: Request header name. +Default = any():: Default value. +Value = binary() | Default:: Request header value. Return the value for the given header. While header names are case insensitive, this function expects the name to be a lowercase binary. -: headers(Req) -> Headers - -Types: +=== headers(Req) -> Headers -* Headers = cowboy:http_headers() +Headers = cowboy:http_headers():: Request headers. Return all headers. -: host(Req) -> Host +=== host(Req) -> Host -Types: - -* Host = binary() +Host = binary():: Requested host. Return the requested host. -: host_info(Req) -> HostInfo - -Types: +=== host_info(Req) -> HostInfo -* HostInfo = cowboy_router:tokens() | undefined +HostInfo = cowboy_router:tokens() | undefined:: Extra tokens for the host. Return the extra tokens from matching against `...` during routing. -: host_url(Req) -> HostURL +=== host_url(Req) -> HostURL -Types: - -* HostURL = binary() | undefined +HostURL = binary() | undefined:: Requested URL, without the path component. Return the requested URL excluding the path component. This function will always return `undefined` until the `cowboy_router` middleware has been executed. -: match_cookies(Fields, Req) -> Map - -Types: +=== match_cookies(Fields, Req) -> Map -* Fields = cowboy:fields() -* Map = map() +Fields = cowboy:fields():: Cookie fields match rules. +Map = map():: Cookie fields matched. Match cookies against the given fields. @@ -153,12 +161,10 @@ be converted through the use of constraints, making this function able to extract, validate and convert values all in one step. -: match_qs(Fields, Req) -> Map - -Types: +=== match_qs(Fields, Req) -> Map -* Fields = cowboy:fields() -* Map = map() +Fields = cowboy:fields():: Query string fields match rules. +Map = map():: Query string fields matched. Match the query string against the given fields. @@ -177,86 +183,88 @@ returned map will be that atom. The value may be converted through the use of constraints, making this function able to extract, validate and convert values all in one step. -: meta(Name, Req) -> meta(Name, Req, undefined) -: meta(Name, Req, Default) -> Value +=== meta(Name, Req) -> meta(Name, Req, undefined) -Types: +Alias for `cowboy_req:meta/3`. -* Name = atom() -* Default = any() -* Value = any() +=== meta(Name, Req, Default) -> Value -Return metadata about the request. +Name = atom():: Metadata name. +Default = any():: Default value. +Value = any():: Metadata value. -: method(Req) -> Method +Return metadata about the request. -Types: +=== method(Req) -> Method -* Method = binary() +Method = binary():: Request method. Return the method. Methods are case sensitive. Standard methods are always uppercase. -: parse_cookies(Req) -> [{Name, Value}] +=== parse_cookies(Req) -> [{Name, Value}] -Types: - -* Name = binary() -* Value = binary() +Name = binary():: Cookie name. +Value = binary():: Cookie value. Parse and return all cookies. Cookie names are case sensitive. -: parse_header(Name, Req) -> see below -: parse_header(Name, Req, Default) -> ParsedValue | Default +=== parse_header(Name, Req) -> see below + +Alias of `cowboy_req:parse_header/3`. + +The `parse_header/2` function will call `parser_header/3` with a +different default value depending on the header being parsed. The +following table summarizes the default values used. + +[cols="<,^",options="header"] +|=== +| Header name | Header value +| content-length | `0` +| cookie | `[]` +| transfer-encoding | `[<<"identity">>]` +| Any other header | `undefined` +|=== -Types: +=== parse_header(Name, Req, Default) -> ParsedValue | Default -* Name = binary() -* Default = any() -* ParsedValue - see below +Name = binary():: Request header name. +Default = any():: Default value. +ParsedValue - see below:: Parsed request header value. Parse the given header. While header names are case insensitive, this function expects the name to be a lowercase binary. -The `parse_header/2` function will call `parser_header/3` with a -different default value depending on the header being parsed. The -following table summarizes the default values used. - -|| Header name Default value -| -| content-length `0` -| cookie `[]` -| transfer-encoding `[<<"identity">>]` -| Any other header `undefined` - The parsed value differs depending on the header being parsed. The following table summarizes the different types returned. -|| Header name Type -| -| accept `[{{Type, SubType, Params}, Quality, AcceptExt}]` -| accept-charset `[{Charset, Quality}]` -| accept-encoding `[{Encoding, Quality}]` -| accept-language `[{LanguageTag, Quality}]` -| authorization `{AuthType, Credentials}` -| content-length `non_neg_integer()` -| content-type `{Type, SubType, ContentTypeParams}` -| cookie `[{binary(), binary()}]` -| expect `[Expect | {Expect, ExpectValue, Params}]` -| if-match `'*' | [{weak | strong, OpaqueTag}]` -| if-modified-since `calendar:datetime()` -| if-none-match `'*' | [{weak | strong, OpaqueTag}]` -| if-unmodified-since `calendar:datetime()` -| range `{Unit, [Range]}` -| sec-websocket-protocol `[binary()]` -| transfer-encoding `[binary()]` -| upgrade `[binary()]` -| x-forwarded-for `[binary()]` +[cols="<,^",options="header"] +|=== +| Header name | Type of parsed header value +| accept | `[{{Type, SubType, Params}, Quality, AcceptExt}]` +| accept-charset | `[{Charset, Quality}]` +| accept-encoding | `[{Encoding, Quality}]` +| accept-language | `[{LanguageTag, Quality}]` +| authorization | `{AuthType, Credentials}` +| content-length | `non_neg_integer()` +| content-type | `{Type, SubType, ContentTypeParams}` +| cookie | `[{binary(), binary()}]` +| expect | `[Expect \| {Expect, ExpectValue, Params}]` +| if-match | `'*' \| [{weak \| strong, OpaqueTag}]` +| if-modified-since | `calendar:datetime()` +| if-none-match | `'*' \| [{weak \| strong, OpaqueTag}]` +| if-unmodified-since | `calendar:datetime()` +| range | `{Unit, [Range]}` +| sec-websocket-protocol | `[binary()]` +| transfer-encoding | `[binary()]` +| upgrade | `[binary()]` +| x-forwarded-for | `[binary()]` +|=== Types for the above table: @@ -292,12 +300,10 @@ The range header value `Range` can take three forms: An `undefined` tuple will be returned if Cowboy doesn't know how to parse the requested header. -: parse_qs(Req) -> [{Name, Value}] +=== parse_qs(Req) -> [{Name, Value}] -Types: - -* Name = binary() -* Value = binary() | true +Name = binary():: Query string field name. +Value = binary() | true:: Query string field value. Return the request's query string as a list of tuples. @@ -306,35 +312,27 @@ Keys with no value are different from keys with an empty value in that they do not have a `=` indicating the presence of a value. -: path(Req) -> Path - -Types: +=== path(Req) -> Path -* Path = binary() +Path = binary():: Requested path. Return the requested path. -: path_info(Req) -> PathInfo +=== path_info(Req) -> PathInfo -Types: - -* PathInfo = cowboy_router:tokens() | undefined +PathInfo = cowboy_router:tokens() | undefined:: Extra tokens for the path. Return the extra tokens from matching against `...` during routing. -: peer(Req) -> Peer - -Types: +=== peer(Req) -> Peer -* Peer = {inet:ip_address(), inet:port_number()} +Peer = {inet:ip_address(), inet:port_number()}:: Peer IP address and port number. Return the client's IP address and port number. -: port(Req) -> Port +=== port(Req) -> Port -Types: - -* Port = inet:port_number() +Port = inet:port_number():: Requested port number. Return the request's port. @@ -342,54 +340,46 @@ The port returned by this function is obtained by parsing the host header. It may be different than the actual port the client used to connect to the Cowboy server. -: qs(Req) -> QueryString - -Types: +=== qs(Req) -> QueryString -* QueryString = binary() +QueryString = binary():: Unprocessed query string. Return the request's query string. -: set_meta(Name, Value, Req) -> Req2 - -Types: +=== set_meta(Name, Value, Req) -> Req2 -* Name = atom() -* Value = any() +Name = atom():: Metadata name. +Value = any():: Metadata value. Set metadata about the request. An existing value will be overwritten. -: url(Req) -> URL +=== url(Req) -> URL -Types: - -* URL = binary() | undefined +URL = binary() | undefined:: Requested URL. Return the requested URL. This function will always return `undefined` until the `cowboy_router` middleware has been executed. -: version(Req) -> Version - -Types: +=== version(Req) -> Version -* Version = cowboy:http_version() +Version = cowboy:http_version():: Client's advertised HTTP version. Return the HTTP version used for this request. -:: Request body related exports +== Request body related exports -: body(Req) -> body(Req, []) -: body(Req, Opts) -> {ok, Data, Req2} | {more, Data, Req2} +=== body(Req) -> body(Req, []) -Types: +Alias of `cowboy_req:body/2`. -* Opts = [body_opt()] -* Data = binary() -* Reason = atom() +=== body(Req, Opts) -> {ok, Data, Req2} | {more, Data, Req2} + +Opts = [body_opt()]:: Request body reading options. +Data = binary():: Data read from the body. Read the request body. @@ -422,11 +412,9 @@ the content-length header if it wasn't already there. This function can only be called once. Cowboy will not cache the result of this call. -: body_length(Req) -> Length - -Types: +=== body_length(Req) -> Length -* Length = non_neg_integer() | undefined +Length = non_neg_integer() | undefined:: Length of the request body. Return the length of the request body. @@ -434,16 +422,15 @@ The length will only be returned if the request does not use any transfer-encoding and if the content-length header is present. -: body_qs(Req) -> body_qs(Req, - [{length, 64000}, {read_length, 64000}, {read_timeout, 5000}]) -: body_qs(Req, Opts) -> {ok, [{Name, Value}], Req2} | {badlength, Req2} +=== body_qs(Req) -> body_qs(Req, [{length, 64000}, {read_length, 64000}, {read_timeout, 5000}]) -Types: +Alias of `cowboy_req:body_qs/2`. -* Opts = [body_opt()] -* Name = binary() -* Value = binary() | true -* Reason = chunked | badlength | atom() +=== body_qs(Req, Opts) -> {ok, [{Name, Value}], Req2} | {badlength, Req2} + +Opts = [body_opt()]:: Request body reading options. +Name = binary():: Field name. +Value = binary() | true:: Field value. Return the request body as a list of tuples. @@ -459,18 +446,18 @@ body is larger then a `badlength` tuple is returned. This function can only be called once. Cowboy will not cache the result of this call. -: has_body(Req) -> boolean() +=== has_body(Req) -> boolean() Return whether the request has a body. -: part(Req) -> part(Req, - [{length, 64000}, {read_length, 64000}, {read_timeout, 5000}]) -: part(Req, Opts) -> {ok, Headers, Req2} | {done, Req2} +=== part(Req) -> part(Req, [{length, 64000}, {read_length, 64000}, {read_timeout, 5000}]) + +Alias of `cowboy_req:part/2`. -Types: +=== part(Req, Opts) -> {ok, Headers, Req2} | {done, Req2} -* Opts = [body_opt()] -* Headers = cow_multipart:headers() +Opts = [body_opt()]:: Request body reading options. +Headers = cow_multipart:headers():: Part's headers. Read the headers for the next part of the multipart message. @@ -496,13 +483,14 @@ of 64KB with a timeout of 5s. This is tailored for reading part headers, not for skipping the previous part's body. You might want to consider skipping large parts manually. -: part_body(Req) -> part_body(Req, []) -: part_body(Req, Opts) -> {ok, Data, Req2} | {more, Data, Req2} +=== part_body(Req) -> part_body(Req, []) + +Alias of `cowboy_req:part_body/2`. -Types: +=== part_body(Req, Opts) -> {ok, Data, Req2} | {more, Data, Req2} -* Opts = [body_opt()] -* Data = binary() +Opts = [body_opt()]:: Request body reading options. +Data = binary():: Part's body. Read the body of the current part of the multipart message. @@ -520,14 +508,11 @@ returned inside an `ok` tuple. Note that once the body has been read, fully or partially, it cannot be read again. -:: Response related exports +== Response related exports -: chunk(Data, Req) -> ok +=== chunk(Data, Req) -> ok -Types: - -* Data = iodata() -* Reason = atom() +Data = iodata():: Chunk data to be sent. Send a chunk of data. @@ -540,13 +525,14 @@ If the request uses HTTP/1.0, the data is sent directly without wrapping it in an HTTP/1.1 chunk, providing compatibility with older clients. -: chunked_reply(StatusCode, Req) -> chunked_reply(StatusCode, [], Req) -: chunked_reply(StatusCode, Headers, Req) -> Req2 +=== chunked_reply(StatusCode, Req) -> chunked_reply(StatusCode, [], Req) + +Alias of `cowboy_req:chunked_reply/3`. -Types: +=== chunked_reply(StatusCode, Headers, Req) -> Req2 -* StatusCode = cowboy:http_status() -* Headers = cowboy:http_headers() +StatusCode = cowboy:http_status():: Response status code. +Headers = cowboy:http_headers():: Response headers. Send a response using chunked transfer-encoding. @@ -564,11 +550,7 @@ compatibility with older clients. This function can only be called once, with the exception of overriding the response in the `onresponse` hook. -: continue(Req) -> ok - -Types: - -* Reason = atom() +=== continue(Req) -> ok Send a 100 Continue intermediate reply. @@ -581,44 +563,44 @@ you may want to do it manually by disabling this behavior with the `continue` body option and then calling this function. -: delete_resp_header(Name, Req) -> Req2 +=== delete_resp_header(Name, Req) -> Req2 -Types: - -* Name = binary() +Name = binary():: Response header name. Delete the given response header. While header names are case insensitive, this function expects the name to be a lowercase binary. -: has_resp_body(Req) -> boolean() +=== has_resp_body(Req) -> boolean() Return whether a response body has been set. This function will return false if a response body has been set with a length of 0. -: has_resp_header(Name, Req) -> boolean() - -Types: +=== has_resp_header(Name, Req) -> boolean() -* Name = binary() +Name = binary():: Response header name. Return whether the given response header has been set. While header names are case insensitive, this function expects the name to be a lowercase binary. -: reply(StatusCode, Req) -> reply(StatusCode, [], Req) -: reply(StatusCode, Headers, Req) - see below -: reply(StatusCode, Headers, Body, Req) -> Req2 +=== reply(StatusCode, Req) -> reply(StatusCode, [], Req) + +Alias of `cowboy_req:reply/3`. -Types: +=== reply(StatusCode, Headers, Req) - see below -* StatusCode = cowboy:http_status() -* Headers = cowboy:http_headers() -* Body = iodata() +Alias of `cowboy_req:reply/4`, with caveats. + +=== reply(StatusCode, Headers, Body, Req) -> Req2 + +StatusCode = cowboy:http_status():: Response status code. +Headers = cowboy:http_headers():: Response headers. +Body = iodata():: Response body. Send a response. @@ -639,26 +621,25 @@ returns. This function can only be called once, with the exception of overriding the response in the `onresponse` hook. -: set_resp_body(Body, Req) -> Req2 +=== set_resp_body(Body, Req) -> Req2 -Types: - -* Body = iodata() +Body = iodata():: Response body. Set a response body. This body will not be sent if `chunked_reply/{2,3}` or `reply/4` is used, as they override it. -: set_resp_body_fun(Fun, Req) -> Req2 -: set_resp_body_fun(Length, Fun, Req) -> Req2 +=== set_resp_body_fun(Fun, Req) -> Req2 + +Alias of `cowboy_req:set_resp_body_fun/3`. -Types: +=== set_resp_body_fun(Length, Fun, Req) -> Req2 -* Fun = fun((Socket, Transport) -> ok) -* Socket = inet:socket() -* Transport = module() -* Length = non_neg_integer() +Fun = fun((Socket, Transport) -> ok):: Fun that will send the response body. +Socket = inet:socket():: Socket for this connection. +Transport = module():: Transport module for this socket. +Length = non_neg_integer():: Length of the response body. Set a fun for sending the response body. @@ -673,12 +654,10 @@ using the `reply/2` or `reply/3` function. The fun will receive the Ranch `Socket` and `Transport` as arguments. Only send and sendfile operations are supported. -: set_resp_body_fun(chunked, Fun, Req) -> Req2 +=== set_resp_body_fun(chunked, Fun, Req) -> Req2 -Types: - -* Fun = fun((ChunkFun) -> ok) -* ChunkFun = fun((iodata()) -> ok) +Fun = fun((ChunkFun) -> ok):: Fun that will send the response body. +ChunkFun = fun((iodata()) -> ok):: Fun to call for every chunk to be sent. Set a fun for sending the response body using chunked transfer-encoding. @@ -690,24 +669,20 @@ be used to send chunks in a similar way to the `chunk/2` function, except the fun only takes one argument, the data to be sent in the chunk. -: set_resp_cookie(Name, Value, Opts, Req) -> Req2 - -Types: +=== set_resp_cookie(Name, Value, Opts, Req) -> Req2 -* Name = iodata() -* Value = iodata() -* Opts = cookie_opts() +Name = iodata():: Cookie name. +Value = iodata():: Cookie value. +Opts = cookie_opts():: Cookie options. Set a cookie in the response. Cookie names are case sensitive. -: set_resp_header(Name, Value, Req) -> Req2 - -Types: +=== set_resp_header(Name, Value, Req) -> Req2 -* Name = binary() -* Value = iodata() +Name = binary():: Response header name. +Value = iodata():: Response header value. Set a response header. diff --git a/doc/src/manual/cowboy_rest.ezdoc b/doc/src/manual/cowboy_rest.asciidoc index 35131c7..6380d41 100644 --- a/doc/src/manual/cowboy_rest.ezdoc +++ b/doc/src/manual/cowboy_rest.asciidoc @@ -1,4 +1,10 @@ -::: cowboy_rest += cowboy_rest(3) + +== Name + +cowboy_rest - REST handlers + +== Description The `cowboy_rest` module implements REST semantics on top of the HTTP protocol. @@ -6,66 +12,53 @@ the HTTP protocol. This module is a sub protocol that defines many callbacks be implemented by handlers. The `init/2` and `terminate/3` callbacks are common to all handler types and are documented -in the manual for the ^cowboy_handler module. +in the manual for the link:cowboy_handler.asciidoc[cowboy_handler] module. All other callbacks are optional, though some may become required depending on the return value of previous callbacks. -:: Meta values - -: charset - -Type: binary() - -Negotiated charset. - -This value may not be defined if no charset was negotiated. - -: language +== Meta values -Type: binary() +charset = binary():: + Negotiated charset. + + + This value may not be defined if no charset was negotiated. -Negotiated language. +language = binary():: + Negotiated language. + + + This value may not be defined if no language was negotiated. -This value may not be defined if no language was negotiated. +media_type = {binary(), binary(), '*' | [{binary(), binary()}]}:: + Negotiated media-type. + + + The media-type is the content-type, excluding the charset. + + + This value is always defined after the call to + `content_types_provided/2`. -: media_type - -Type: {binary(), binary(), '*' | [{binary(), binary()}]} - -Negotiated media-type. - -The media-type is the content-type, excluding the charset. - -This value is always defined after the call to -`content_types_provided/2`. - -:: Terminate reasons +== Terminate reasons The following values may be received as the terminate reason in the optional `terminate/3` callback. -: normal - -The connection was closed normally. - -: {crash, Class, Reason} - -A crash occurred in the handler. `Class` and `Reason` can be -used to obtain more information about the crash. The function -`erlang:get_stacktrace/0` can also be called to obtain the -stacktrace of the process when the crash occurred. +normal:: + The connection was closed normally. -:: Callbacks +{crash, Class, Reason}:: + A crash occurred in the handler. `Class` and `Reason` can be + used to obtain more information about the crash. The function + `erlang:get_stacktrace/0` can also be called to obtain the + stacktrace of the process when the crash occurred. -: Callback(Req, State) -> {Value, Req, State} | {stop, Req, State} +== Callbacks -Types: +=== Callback(Req, State) -> {Value, Req, State} | {stop, Req, State} -* Callback - one of the REST callbacks described below -* Req = cowboy_req:req() -* State = any() -* Value - see the REST callbacks description below +Callback:: One of the REST callbacks described below. +Req = cowboy_req:req():: The Req object. +State = any():: Handler state. +Value:: See the REST callbacks description below. Please see the REST callbacks description below for details on the `Value` type, the default value if the callback is @@ -76,23 +69,23 @@ The `stop` tuple can be returned to stop REST processing. It is up to the resource code to send a reply before that, otherwise a `204 No Content` will be sent. -:: REST callbacks description +== REST callbacks description -: allowed_methods +=== allowed_methods -* Methods: all -* Value type: [binary()] -* Default value: [<<"GET">>, <<"HEAD">>, <<"OPTIONS">>] +Methods:: all +Value type:: [binary()] +Default value:: `[<<"GET">>, <<"HEAD">>, <<"OPTIONS">>]` Return the list of allowed methods. Methods are case sensitive. Standard methods are always uppercase. -: allow_missing_post +=== allow_missing_post -* Methods: POST -* Value type: boolean() -* Default value: true +Methods:: POST +Value type:: boolean() +Default value:: true Return whether POST is allowed when the resource doesn't exist. @@ -100,11 +93,11 @@ Returning `true` here means that a new resource will be created. The URL to the created resource should also be returned from the `AcceptResource` callback. -: charsets_provided +=== charsets_provided -* Methods: GET, HEAD, POST, PUT, PATCH, DELETE -* Value type: [binary()] -* Skip to the next step if undefined +Methods:: GET, HEAD, POST, PUT, PATCH, DELETE +Value type:: [binary()] +Default behavior:: Skip to the next step if undefined. Return the list of charsets the resource provides. @@ -120,14 +113,14 @@ value `charset`. While charsets are case insensitive, this callback is expected to return them as lowercase binary. -: content_types_accepted +=== content_types_accepted -* Methods: POST, PUT, PATCH -* No default +Methods:: POST, PUT, PATCH +Value type:: [{binary() | {Type, SubType, Params}, AcceptResource}] +Default behavior:: Crash if undefined. -Types: +With types: -* Value = [{binary() | {Type, SubType, Params}, AcceptResource}] * Type = SubType = binary() * Params = '*' | [{binary(), binary()}] * AcceptResource = atom() @@ -155,8 +148,8 @@ different list for each methods. The `AcceptResource` value is the name of the callback that will be called if the content-type matches. It is defined as follow. -* Value type: true | {true, URL} | false -* No default +Value type:: true | {true, URL} | false +Default behavior:: Crash if undefined. Process the request body. @@ -174,14 +167,14 @@ and language can be retrieved using the `cowboy_req:meta/{2,3}` functions. The respective keys are `media_type`, `charset` and `language`. The body can be set using `cowboy_req:set_resp_body/2`. -: content_types_provided +=== content_types_provided -* Methods: GET, HEAD, POST, PUT, PATCH, DELETE -* Default value: [{{<<"text">>, <<"html">>, '*'}, to_html}] +Methods:: GET, HEAD, POST, PUT, PATCH, DELETE +Value type:: [{binary() | {Type, SubType, Params}, ProvideResource}] +Default value:: `[{{<<"text">>, <<"html">>, '*'}, to_html}]` -Types: +With types: -* Value = [{binary() | {Type, SubType, Params}, ProvideResource}] * Type = SubType = binary() * Params = '*' | [{binary(), binary()}] * ProvideResource = atom() @@ -205,9 +198,9 @@ be called if the content-type matches. It will only be called when a representation of the resource needs to be returned. It is defined as follow. -* Methods: GET, HEAD -* Value type: iodata() | {stream, Fun} | {stream, Len, Fun} | {chunked, ChunkedFun} -* No default +Methods:: GET, HEAD +Value type:: iodata() | {stream, Fun} | {stream, Len, Fun} | {chunked, ChunkedFun} +Default behavior:: Crash if undefined. Return the response body. @@ -220,11 +213,11 @@ The call to this callback happens a good time after the call to `content_types_provided/2`, when it is time to start rendering the response body. -: delete_completed +=== delete_completed -* Methods: DELETE -* Value type: boolean() -* Default value: true +Methods:: DELETE +Value type:: boolean() +Default value:: true Return whether the delete action has been completed. @@ -235,11 +228,11 @@ including from any internal cache. When this function returns `false`, a `202 Accepted` response will be sent instead of a `200 OK` or `204 No Content`. -: delete_resource +=== delete_resource -* Methods: DELETE -* Value type: boolean() -* Default value: false +Methods:: DELETE +Value type:: boolean() +Default value:: false Delete the resource. @@ -247,21 +240,21 @@ The value returned indicates if the action was successful, regardless of whether the resource is immediately deleted from the system. -: expires +=== expires -* Methods: GET, HEAD -* Value type: calendar:datetime() | binary() | undefined -* Default value: undefined +Methods:: GET, HEAD +Value type:: calendar:datetime() | binary() | undefined +Default value:: undefined Return the date of expiration of the resource. This date will be sent as the value of the expires header. -: forbidden +=== forbidden -* Methods: all -* Value type: boolean() -* Default value: false +Methods:: all +Value type:: boolean() +Default value:: false Return whether access to the resource is forbidden. @@ -270,11 +263,11 @@ function returns `true`. This status code means that access is forbidden regardless of authentication, and that the request shouldn't be repeated. -: generate_etag +=== generate_etag -* Methods: GET, HEAD, POST, PUT, PATCH, DELETE -* Value type: binary() | {weak | strong, binary()} -* Default value: undefined +Methods:: GET, HEAD, POST, PUT, PATCH, DELETE +Value type:: binary() | {weak | strong, binary()} +Default value:: undefined Return the entity tag of the resource. @@ -284,13 +277,13 @@ If a binary is returned, then the value will be parsed to the tuple form automatically. The value must be in the same format as the etag header, including quotes. -: is_authorized +=== is_authorized -* Methods: all -* Value type: true | {false, AuthHeader} -* Default value: true +Methods:: all +Value type:: true | {false, AuthHeader} +Default value:: true -Types: +With types: * AuthHead = iodata() @@ -304,22 +297,22 @@ If the authentication fails, the value returned will be sent as the value for the www-authenticate header in the `401 Unauthorized` response. -: is_conflict +=== is_conflict -* Methods: PUT -* Value type: boolean() -* Default value: false +Methods:: PUT +Value type:: boolean() +Default value:: false Return whether the put action results in a conflict. A `409 Conflict` response will be sent if this function returns `true`. -: known_methods +=== known_methods -* Methods: all -* Value type: [binary()] -* Default value: [<<"GET">>, <<"HEAD">>, <<"POST">>, <<"PUT">>, <<"PATCH">>, <<"DELETE">>, <<"OPTIONS">>] +Methods:: all +Value type:: [binary()] +Default value:: `[<<"GET">>, <<"HEAD">>, <<"POST">>, <<"PUT">>, <<"PATCH">>, <<"DELETE">>, <<"OPTIONS">>]` Return the list of known methods. @@ -331,11 +324,11 @@ implement in `cowboy_rest`. Methods are case sensitive. Standard methods are always uppercase. -: languages_provided +=== languages_provided -* Methods: GET, HEAD, POST, PUT, PATCH, DELETE -* Value type: [binary()] -* Skip to the next step if undefined +Methods:: GET, HEAD, POST, PUT, PATCH, DELETE +Value type:: [binary()] +Default behavior:: Skip to the next step if undefined. Return the list of languages the resource provides. @@ -351,11 +344,11 @@ value `language`. While languages are case insensitive, this callback is expected to return them as lowercase binary. -: last_modified +=== last_modified -* Methods: GET, HEAD, POST, PUT, PATCH, DELETE -* Value type: calendar:datetime() -* Default value: undefined +Methods:: GET, HEAD, POST, PUT, PATCH, DELETE +Value type:: calendar:datetime() +Default value:: undefined Return the date of last modification of the resource. @@ -363,11 +356,11 @@ This date will be used to test against the if-modified-since and if-unmodified-since headers, and sent as the last-modified header in the response of GET and HEAD requests. -: malformed_request +=== malformed_request -* Methods: all -* Value type: boolean() -* Default value: false +Methods:: all +Value type:: boolean() +Default value:: false Return whether the request is malformed. @@ -378,13 +371,13 @@ are expected to implement it. The check is to be done on the request itself, not on the request body, which is processed later. -: moved_permanently +=== moved_permanently -* Methods: GET, HEAD, POST, PUT, PATCH, DELETE -* Value type: {true, URL} | false -* Default value: false +Methods:: GET, HEAD, POST, PUT, PATCH, DELETE +Value type:: {true, URL} | false +Default value:: false -Types: +With types: * URL = iodata() @@ -393,13 +386,13 @@ Return whether the resource was permanently moved. If it was, its new URL is also returned and sent in the location header in the response. -: moved_temporarily +=== moved_temporarily -* Methods: GET, HEAD, POST, PATCH, DELETE -* Value type: {true, URL} | false -* Default value: false +Methods:: GET, HEAD, POST, PATCH, DELETE +Value type:: {true, URL} | false +Default value:: false -Types: +With types: * URL = iodata() @@ -408,11 +401,11 @@ Return whether the resource was temporarily moved. If it was, its new URL is also returned and sent in the location header in the response. -: multiple_choices +=== multiple_choices -* Methods: GET, HEAD, POST, PUT, PATCH, DELETE -* Value type: boolean() -* Default value: false +Methods:: GET, HEAD, POST, PUT, PATCH, DELETE +Value type:: boolean() +Default value:: false Return whether there are multiple representations of the resource. @@ -425,11 +418,11 @@ The content-type of the response should be the one previously negociated and that can be obtained by calling `cowboy_req:meta(media_type, Req)`. -: options +=== options -* Methods: OPTIONS -* Value type: ok -* Default value: ok +Methods:: OPTIONS +Value type:: ok +Default value:: ok Handle a request for information. @@ -439,19 +432,19 @@ options available for this resource. By default, Cowboy will send a `200 OK` response with the allow header set. -: previously_existed +=== previously_existed -* Methods: GET, HEAD, POST, PATCH, DELETE -* Value type: boolean() -* Default value: false +Methods:: GET, HEAD, POST, PATCH, DELETE +Value type:: boolean() +Default value:: false Return whether the resource existed previously. -: resource_exists +=== resource_exists -* Methods: GET, HEAD, POST, PUT, PATCH, DELETE -* Value type: boolean() -* Default value: true +Methods:: GET, HEAD, POST, PUT, PATCH, DELETE +Value type:: boolean() +Default value:: true Return whether the resource exists. @@ -459,11 +452,11 @@ If it exists, conditional headers will be tested before attempting to perform the action. Otherwise, Cowboy will check if the resource previously existed first. -: service_available +=== service_available -* Methods: all -* Value type: boolean() -* Default value: true +Methods:: all +Value type:: boolean() +Default value:: true Return whether the service is available. @@ -473,11 +466,11 @@ systems are up and able to handle requests. A `503 Service Unavailable` response will be sent if this function returns `false`. -: uri_too_long +=== uri_too_long -* Methods: all -* Value type: boolean() -* Default value: false +Methods:: all +Value type:: boolean() +Default value:: false Return whether the requested URI is too long. @@ -488,11 +481,11 @@ are expected to implement it. A `414 Request-URI Too Long` response will be sent if this function returns `true`. -: valid_content_headers +=== valid_content_headers -* Methods: all -* Value type: boolean() -* Default value: true +Methods:: all +Value type:: boolean() +Default value:: true Return whether the content-* headers are valid. @@ -505,22 +498,22 @@ quickly check the headers can be parsed. A `501 Not Implemented` response will be sent if this function returns `false`. -: valid_entity_length +=== valid_entity_length -* Methods: all -* Value type: boolean() -* Default value: true +Methods:: all +Value type:: boolean() +Default value:: true Return whether the request body length is within acceptable boundaries. A `413 Request Entity Too Large` response will be sent if this function returns `false`. -: variances +=== variances -* Methods: GET, HEAD, POST, PUT, PATCH, DELETE -* Value type: [binary()] -* Default value: [] +Methods:: GET, HEAD, POST, PUT, PATCH, DELETE +Value type:: [binary()] +Default value:: [] Return the list of headers that affect the representation of the resource. diff --git a/doc/src/manual/cowboy_router.ezdoc b/doc/src/manual/cowboy_router.asciidoc index 8d45e67..9142930 100644 --- a/doc/src/manual/cowboy_router.ezdoc +++ b/doc/src/manual/cowboy_router.asciidoc @@ -1,4 +1,10 @@ -::: cowboy_router += cowboy_router(3) + +== Name + +cowboy_router - router middleware + +== Description The `cowboy_router` middleware maps the requested host and path to the handler to be used for processing the request. @@ -7,49 +13,44 @@ to the `compile/1` function for this purpose. It adds the handler name and options to the environment as the values `handler` and `handler_opts` respectively. -Environment input: +=== Environment input -* dispatch = dispatch_rules() +dispatch = dispatch_rules():: Dispatch table. -Environment output: +=== Environment output -* handler = module() -* handler_opts = any() +handler = module():: Handler module. +handler_opts = any():: Handler options. -:: Types +== Types -: bindings() = [{atom(), binary()}] +=== bindings() = [{atom(), binary()}] List of bindings found during routing. -: dispatch_rules() - opaque to the user +=== dispatch_rules() - opaque to the user Rules for dispatching request used by Cowboy. -: routes() = [{Host, Paths} | {Host, cowboy:fields(), Paths}] +=== routes() = [{Host, Paths} | {Host, cowboy:fields(), Paths}] -Types: +With types: * Host = Path = '_' | iodata() -* Paths = [{Path, Handler, Opts} | {Path, cowboy:fields(), Handler, Opts}] +* Paths = [{Path, Handler, Opts} | {Path, cowboy:fields(), Handler, HandlerOpts}] * Handler = module() -* Opts = any() +* HandlerOpts = any() Human readable list of routes mapping hosts and paths to handlers. The syntax for routes is defined in the user guide. -: tokens() = [binary()] +=== tokens() = [binary()] List of host_info and path_info tokens found during routing. -:: Exports - -: compile(Routes) -> Dispatch - -Types: +== Exports -* Routes = routes() -* Dispatch = dispatch_rules() +=== compile(routes()) -> dispatch_rules() Compile the routes for use by Cowboy. diff --git a/doc/src/manual/cowboy_spdy.asciidoc b/doc/src/manual/cowboy_spdy.asciidoc new file mode 100644 index 0000000..b0dcb70 --- /dev/null +++ b/doc/src/manual/cowboy_spdy.asciidoc @@ -0,0 +1,42 @@ += cowboy_spdy(3) + +== Name + +cowboy_spdy - SPDY protocol + +== Description + +The `cowboy_spdy` module implements SPDY/3 as a Ranch protocol. + +== Types + +=== opts() = [Option] + +[source,erlang] +---- +Option = {env, cowboy_middleware:env()} + | {middlewares, [module()]} + | {onresponse, cowboy:onresponse_fun()} +---- + +Configuration for the SPDY protocol handler. + +This configuration is passed to Cowboy when starting listeners +using the `cowboy:start_spdy/4` function. + +It can be updated without restarting listeners using the +Ranch functions `ranch:get_protocol_options/1` and +`ranch:set_protocol_options/2`. + +== Option descriptions + +The default value is given next to the option name. + +env ([{listener, Ref}]):: + Initial middleware environment. + +middlewares ([cowboy_router, cowboy_handler]):: + List of middlewares to execute for every requests. + +onresponse (undefined):: + Fun called every time a response is sent. diff --git a/doc/src/manual/cowboy_spdy.ezdoc b/doc/src/manual/cowboy_spdy.ezdoc deleted file mode 100644 index e88de20..0000000 --- a/doc/src/manual/cowboy_spdy.ezdoc +++ /dev/null @@ -1,34 +0,0 @@ -::: cowboy_spdy - -The `cowboy_spdy` module implements SPDY/3 as a Ranch protocol. - -:: Types - -: opts() = [{env, cowboy_middleware:env()} - | {middlewares, [module()]} - | {onresponse, cowboy:onresponse_fun()}] - -Configuration for the SPDY protocol handler. - -This configuration is passed to Cowboy when starting listeners -using the `cowboy:start_spdy/4` function. - -It can be updated without restarting listeners using the -Ranch functions `ranch:get_protocol_options/1` and -`ranch:set_protocol_options/2`. - -:: Option descriptions - -The default value is given next to the option name. - -: env ([{listener, Ref}]) - -Initial middleware environment. - -: middlewares ([cowboy_router, cowboy_handler]) - -List of middlewares to execute for every requests. - -: onresponse (undefined) - -Fun called every time a response is sent. diff --git a/doc/src/manual/cowboy_static.asciidoc b/doc/src/manual/cowboy_static.asciidoc new file mode 100644 index 0000000..658d93b --- /dev/null +++ b/doc/src/manual/cowboy_static.asciidoc @@ -0,0 +1,41 @@ += cowboy_static(3) + +== Name + +cowboy_static - static file handler + +== Description + +The `cowboy_static` module implements file serving capabilities +by using the REST semantics provided by `cowboy_rest`. + +== Types + +=== opts() = [Option] + +[source,erlang] +---- +Option = {priv_file, atom(), string() | binary()} + | {priv_file, atom(), string() | binary(), Extra} + | {file, string() | binary()} + | {file, string() | binary(), Extra} + | {priv_dir, atom(), string() | binary()} + | {priv_dir, atom(), string() | binary(), Extra} + | {dir, string() | binary()} + | {dir, string() | binary(), Extra} + +Extra = [ETag | Mimetypes] + +ETag = {etag, module(), function()} | {etag, false} + +Mimetypes = {mimetypes, module(), function()} + | {mimetypes, binary() | {binary(), binary(), [{binary(), binary()}]}} +---- + +Configuration for the static handler. + +The handler can be configured for sending either one file or +a directory (including its subdirectories). + +Extra options allow you to define how the etag should be calculated +and how the mimetype of files should be detected. diff --git a/doc/src/manual/cowboy_static.ezdoc b/doc/src/manual/cowboy_static.ezdoc deleted file mode 100644 index a827832..0000000 --- a/doc/src/manual/cowboy_static.ezdoc +++ /dev/null @@ -1,32 +0,0 @@ -::: cowboy_static - -The `cowboy_static` module implements file serving capabilities -by using the REST semantics provided by `cowboy_rest`. - -:: Types - -: opts() = {priv_file, atom(), string() | binary()} - | {priv_file, atom(), string() | binary(), extra()} - | {file, string() | binary()} - | {file, string() | binary(), extra()} - | {priv_dir, atom(), string() | binary()} - | {priv_dir, atom(), string() | binary(), extra()} - | {dir, string() | binary()} - | {dir, string() | binary(), extra()} - -Configuration for the static handler. - -The handler can be configured for sending either one file or -a directory (including its subdirectories). - -Extra options allow you to define how the etag should be calculated -and how the mimetype of files should be detected. They are defined -as follow, but do note that these types are not exported, only the -`opts/0` type is public. - -: extra() = [extra_etag() | extra_mimetypes()] - -: extra_etag() = {etag, module(), function()} | {etag, false} - -: extra_mimetypes() = {mimetypes, module(), function()} - | {mimetypes, binary() | {binary(), binary(), [{binary(), binary()}]}} diff --git a/doc/src/manual/cowboy_sub_protocol.asciidoc b/doc/src/manual/cowboy_sub_protocol.asciidoc new file mode 100644 index 0000000..8146a44 --- /dev/null +++ b/doc/src/manual/cowboy_sub_protocol.asciidoc @@ -0,0 +1,27 @@ += cowboy_sub_protocol(3) + +== Name + +cowboy_sub_protocol - sub protocol + +== Description + +The `cowboy_sub_protocol` behaviour defines the interface used +by modules that implement a protocol on top of HTTP. + +== Callbacks + +=== upgrade(Req, Env, Handler, HandlerOpts) -> {ok, Req, Env} | {suspend, Module, Function, Args} | {stop, Req} + +Req = cowboy_req:req():: The Req object. +Env = env():: The request environment. +Handler = module():: Handler module. +Opts = any():: Handler options. +Module = module():: MFA to call when resuming the process. +Function = atom():: MFA to call when resuming the process. +Args = [any()]:: MFA to call when resuming the process. + +Upgrade the protocol. + +Please refer to the `cowboy_middleware` manual for a +description of the return values. diff --git a/doc/src/manual/cowboy_sub_protocol.ezdoc b/doc/src/manual/cowboy_sub_protocol.ezdoc deleted file mode 100644 index ee57beb..0000000 --- a/doc/src/manual/cowboy_sub_protocol.ezdoc +++ /dev/null @@ -1,27 +0,0 @@ -::: cowboy_sub_protocol - -The `cowboy_sub_protocol` behaviour defines the interface used -by modules that implement a protocol on top of HTTP. - -:: Callbacks - -: upgrade(Req, Env, Handler, Opts) - -> {ok, Req, Env} - | {suspend, Module, Function, Args} - | {stop, Req} - -Types: - -* Req = cowboy_req:req() -* Env = env() -* Handler = module() -* Opts = any() -* Module = module() -* Function = atom() -* Args = [any()] -* StatusCode = cowboy:http_status() - -Upgrade the protocol. - -Please refer to the `cowboy_middleware` manual for a -description of the return values. diff --git a/doc/src/manual/cowboy_websocket.ezdoc b/doc/src/manual/cowboy_websocket.asciidoc index 2519dba..ac9016b 100644 --- a/doc/src/manual/cowboy_websocket.ezdoc +++ b/doc/src/manual/cowboy_websocket.asciidoc @@ -1,11 +1,17 @@ -::: cowboy_websocket += cowboy_websocket(3) + +== Name + +cowboy_websocket - Websocket protocol + +== Description The `cowboy_websocket` module implements the Websocket protocol. This module is a sub protocol that defines four callbacks to be implemented by handlers. The `init/2` and `terminate/3` callbacks are common to all handler types and are documented -in the manual for the ^cowboy_handler module. +in the manual for the link:cowboy_handler.asciidoc[cowboy_handler] module. The `websocket_handle/3` and `websocket_info/3` callbacks are specific to Websocket handlers and will be called as many times @@ -22,91 +28,77 @@ Cowboy will terminate the process right after closing the Websocket connection. This means that there is no real need to perform any cleanup in the optional `terminate/3` callback. -:: Meta values - -: websocket_compress - -Type: true | false +== Meta values -Whether a websocket compression extension in in use. +websocket_compress = boolean():: + Whether a websocket compression extension in in use. -: websocket_version +websocket_version = 7 | 8 | 13:: + The version of the Websocket protocol being used. -Type: 7 | 8 | 13 - -The version of the Websocket protocol being used. - -:: Terminate reasons +== Terminate reasons The following values may be received as the terminate reason in the optional `terminate/3` callback. -: normal - -The connection was closed normally before establishing a Websocket -connection. This typically happens if an `ok` tuple is returned -from the `init/2` callback. - -: remote - -The remote endpoint closed the connection without giving any -further details. +normal:: + The connection was closed normally before establishing a Websocket + connection. This typically happens if an `ok` tuple is returned + from the `init/2` callback. -: {remote, Code, Payload} +remote:: + The remote endpoint closed the connection without giving any + further details. -The remote endpoint closed the connection with the given -`Code` and `Payload` as the reason. +{remote, Code, Payload}:: + The remote endpoint closed the connection with the given + `Code` and `Payload` as the reason. -: stop +stop:: + The handler requested to close the connection, either by returning + a `stop` tuple or by sending a `close` frame. -The handler requested to close the connection, either by returning -a `stop` tuple or by sending a `close` frame. +timeout:: + The connection has been closed due to inactivity. The timeout + value can be configured from `init/2`. -: timeout +{crash, Class, Reason}:: + A crash occurred in the handler. `Class` and `Reason` can be + used to obtain more information about the crash. The function + `erlang:get_stacktrace/0` can also be called to obtain the + stacktrace of the process when the crash occurred. -The connection has been closed due to inactivity. The timeout -value can be configured from `init/2`. +{error, badencoding}:: + A text frame was sent by the client with invalid encoding. All + text frames must be valid UTF-8. -: {crash, Class, Reason} +{error, badframe}:: + A protocol error has been detected. -A crash occurred in the handler. `Class` and `Reason` can be -used to obtain more information about the crash. The function -`erlang:get_stacktrace/0` can also be called to obtain the -stacktrace of the process when the crash occurred. +{error, closed}:: + The socket has been closed brutally without a close frame being + received first. -: {error, badencoding} +{error, Reason}:: + A socket error ocurred. -A text frame was sent by the client with invalid encoding. All -text frames must be valid UTF-8. +== Callbacks -: {error, badframe} +=== websocket_handle(InFrame, Req, State) -> Ret -A protocol error has been detected. - -: {error, closed} - -The socket has been closed brutally without a close frame being -received first. - -: {error, Reason} - -A socket error ocurred. - -:: Callbacks - -: websocket_handle(InFrame, Req, State) - -> {ok, Req, State} +[source,erlang] +---- +Ret = {ok, Req, State} | {ok, Req, State, hibernate} | {reply, OutFrame | [OutFrame], Req, State} | {reply, OutFrame | [OutFrame], Req, State, hibernate} | {stop, Req, State} -Types: - -* InFrame = {text | binary | ping | pong, binary()} -* Req = cowboy_req:req() -* State = any() -* OutFrame = cow_ws:frame() +InFrame = {text | binary | ping | pong, binary()} +Req = cowboy_req:req() +State = any() +OutFrame = cow_ws:frame() +---- Handle the data received from the Websocket connection. @@ -121,19 +113,21 @@ The `hibernate` option will hibernate the process until it receives new data from the Websocket connection or an Erlang message. -: websocket_info(Info, Req, State) - -> {ok, Req, State} +=== websocket_info(Info, Req, State) -> Ret + +[source,erlang] +---- +Ret = {ok, Req, State} | {ok, Req, State, hibernate} | {reply, OutFrame | [OutFrame], Req, State} | {reply, OutFrame | [OutFrame], Req, State, hibernate} | {stop, Req, State} -Types: - -* Info = any() -* Req = cowboy_req:req() -* State = any() -* OutFrame = cow_ws:frame() +Info = any() +Req = cowboy_req:req() +State = any() +OutFrame = cow_ws:frame() +---- Handle the Erlang message received. diff --git a/doc/src/manual/http_status_codes.ezdoc b/doc/src/manual/http_status_codes.asciidoc index 4d24b20..172272a 100644 --- a/doc/src/manual/http_status_codes.ezdoc +++ b/doc/src/manual/http_status_codes.asciidoc @@ -1,61 +1,67 @@ -::: HTTP status codes += HTTP status codes(7) + +== Name + +HTTP status codes - status codes used by Cowboy + +== Description This chapter aims to list all HTTP status codes that Cowboy may return, with details on the reasons why. The list given here only includes the replies that Cowboy sends, not user replies. -: 100 Continue +== 100 Continue When the client sends an `expect: 100-continue` header, Cowboy automatically sends a this status code before trying to read the request body. This behavior can be disabled using the appropriate body option. -: 101 Switching Protocols +== 101 Switching Protocols This is the status code sent when switching to the Websocket protocol. -: 200 OK +== 200 OK This status code is sent by `cowboy_rest`. -: 201 Created +== 201 Created This status code is sent by `cowboy_rest`. -: 202 Accepted +== 202 Accepted This status code is sent by `cowboy_rest`. -: 204 No Content +== 204 No Content This status code is sent when the processing of a request ends without any reply having been sent. It may also be sent by `cowboy_rest` under normal conditions. -: 300 Multiple Choices +== 300 Multiple Choices This status code is sent by `cowboy_rest`. -: 301 Moved Permanently +== 301 Moved Permanently This status code is sent by `cowboy_rest`. -: 303 See Other +== 303 See Other This status code is sent by `cowboy_rest`. -: 304 Not Modified +== 304 Not Modified This status code is sent by `cowboy_rest`. -: 307 Temporary Redirect +== 307 Temporary Redirect This status code is sent by `cowboy_rest`. -: 400 Bad Request +== 400 Bad Request Cowboy will send this status code for any of the following reasons: @@ -73,78 +79,78 @@ following reasons: * REST under normal conditions. * A Websocket upgrade failed. -: 401 Unauthorized +== 401 Unauthorized This status code is sent by `cowboy_rest`. -: 403 Forbidden +== 403 Forbidden This status code is sent by `cowboy_rest`. -: 404 Not Found +== 404 Not Found This status code is sent when the router successfully resolved the host but didn't find a matching path for the request. It may also be sent by `cowboy_rest` under normal conditions. -: 405 Method Not Allowed +== 405 Method Not Allowed This status code is sent by `cowboy_rest`. -: 406 Not Acceptable +== 406 Not Acceptable This status code is sent by `cowboy_rest`. -: 408 Request Timeout +== 408 Request Timeout Cowboy will send this status code to the client if the client started to send a request, indicated by the request-line being received fully, but failed to send all headers in a reasonable time. -: 409 Conflict +== 409 Conflict This status code is sent by `cowboy_rest`. -: 410 Gone +== 410 Gone This status code is sent by `cowboy_rest`. -: 412 Precondition Failed +== 412 Precondition Failed This status code is sent by `cowboy_rest`. -: 413 Request Entity Too Large +== 413 Request Entity Too Large This status code is sent by `cowboy_rest`. -: 414 Request-URI Too Long +== 414 Request-URI Too Long Cowboy will send this status code to the client if the request-line is too long. It may also be sent by `cowboy_rest` under normal conditions. -: 415 Unsupported Media Type +== 415 Unsupported Media Type This status code is sent by `cowboy_rest`. -: 500 Internal Server Error +== 500 Internal Server Error This status code is sent when a crash occurs in HTTP, loop or REST handlers, or when an invalid return value is returned. It may also be sent by `cowboy_rest` under normal conditions. -: 501 Not Implemented +== 501 Not Implemented This status code is sent by `cowboy_rest`. -: 503 Service Unavailable +== 503 Service Unavailable This status code is sent by `cowboy_rest`. -: 505 HTTP Version Not Supported +== 505 HTTP Version Not Supported Cowboy only supports the versions 1.0 and 1.1 of HTTP. In all other cases this status code is sent back to the diff --git a/doc/src/manual/index.ezdoc b/doc/src/manual/index.ezdoc deleted file mode 100644 index 133a341..0000000 --- a/doc/src/manual/index.ezdoc +++ /dev/null @@ -1,18 +0,0 @@ -::: Cowboy Function Reference - -The function reference documents the public interface of Cowboy. - -* ^"The Cowboy Application^cowboy_app -* ^cowboy -* ^cowboy_handler -* ^cowboy_loop -* ^cowboy_middleware -* ^cowboy_protocol -* ^cowboy_req -* ^cowboy_rest -* ^cowboy_router -* ^cowboy_spdy -* ^cowboy_static -* ^cowboy_sub_protocol -* ^cowboy_websocket -* ^"HTTP status codes^http_status_codes |