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-rw-r--r--doc/src/manual/cowboy_http.asciidoc8
-rw-r--r--doc/src/manual/cowboy_http2.asciidoc8
-rw-r--r--doc/src/manual/cowboy_websocket.asciidoc226
3 files changed, 129 insertions, 113 deletions
diff --git a/doc/src/manual/cowboy_http.asciidoc b/doc/src/manual/cowboy_http.asciidoc
index 4a10c52..4924d46 100644
--- a/doc/src/manual/cowboy_http.asciidoc
+++ b/doc/src/manual/cowboy_http.asciidoc
@@ -9,9 +9,7 @@ cowboy_http - HTTP/1.1
The module `cowboy_http` implements HTTP/1.1 and HTTP/1.0
as a Ranch protocol.
-== Types
-
-=== opts()
+== Options
[source,erlang]
----
@@ -40,9 +38,7 @@ 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.
+The default value is given next to the option name:
env (#{})::
Middleware environment.
diff --git a/doc/src/manual/cowboy_http2.asciidoc b/doc/src/manual/cowboy_http2.asciidoc
index 739374b..d82bc76 100644
--- a/doc/src/manual/cowboy_http2.asciidoc
+++ b/doc/src/manual/cowboy_http2.asciidoc
@@ -9,9 +9,7 @@ cowboy_http2 - HTTP/2
The module `cowboy_http2` implements HTTP/2
as a Ranch protocol.
-== Types
-
-=== opts()
+== Options
[source,erlang]
----
@@ -31,9 +29,7 @@ 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.
+The default value is given next to the option name:
env (#{})::
Middleware environment.
diff --git a/doc/src/manual/cowboy_websocket.asciidoc b/doc/src/manual/cowboy_websocket.asciidoc
index b76d5e1..a884811 100644
--- a/doc/src/manual/cowboy_websocket.asciidoc
+++ b/doc/src/manual/cowboy_websocket.asciidoc
@@ -2,140 +2,164 @@
== Name
-cowboy_websocket - Websocket protocol
+cowboy_websocket - Websocket
== Description
-The `cowboy_websocket` module implements the Websocket protocol.
+The module `cowboy_websocket` implements Websocket
+as a Ranch protocol. It also defines a callback interface
+for handling Websocket connections.
-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 link:cowboy_handler.asciidoc[cowboy_handler] module.
+== Options
-The `websocket_handle/2` and `websocket_info/2` callbacks are
-specific to Websocket handlers and will be called as many times
-as necessary until the Websocket connection is closed.
+[source,erlang]
+----
+opts() :: #{
+ websocket_compress := boolean()
+}
+----
-The `init/2` callback can be used to negotiate Websocket protocol
-extensions with the client. It is highly recommended to return a
-timeout value from this 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.
+Configuration for the Websocket protocol.
-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.
+This configuration is passed to Cowboy when starting listeners
+using `cowboy:start_clear/4` or `cowboy:start_tls/4` functions.
+
+It can be updated without restarting listeners using the
+Ranch functions `ranch:get_protocol_options/1` and
+`ranch:set_protocol_options/2`.
+
+The default value is given next to the option name:
+
+websocket_compress (false)::
+ Whether to enable the Websocket frame compression
+ extension. Frames will only be compressed for the
+ clients that support this extension.
+
+== Callbacks
-== Meta values
+Websocket handlers must implement the following callback
+interface:
-websocket_compress = boolean()::
- Whether a websocket compression extension in in use.
+[source,erlang]
+----
+init(Req, State)
+ -> {cowboy_websocket, Req, State}
+ | {cowboy_websocket, Req, State, hibernate}
+ | {cowboy_websocket, Req, State, timeout()}
+ | {cowboy_websocket, Req, State, timeout(), hibernate}
+
+websocket_init(State) -> CallResult %% optional
+websocket_handle(InFrame, State) -> CallResult
+websocket_info(Info, State) -> CallResult
+
+terminate(Reason, undefined, State) -> any() %% optional
+
+Req :: cowboy_req:req()
+State :: any()
+InFrame :: {text | binary | ping | pong, binary()}
+OutFrame :: cow_ws:frame()
+Info :: any()
+
+CallResult :: {ok, State}
+ | {ok, State, hibernate}
+ | {reply, OutFrame | [OutFrame], State}
+ | {reply, OutFrame | [OutFrame], State, hibernate}
+ | {stop, State}
+
+Reason :: normal | stop | timeout
+ | remote | {remote, cow_ws:close_code(), binary()}
+ | {error, badencoding | badframe | closed | atom()}
+ | {crash, error | exit | throw, any()}
+----
+
+The `init/2` callback is common to all handlers. To upgrade
+the connection to Websocket, it must return `cowboy_websocket`
+as the first element of the tuple.
+
+Any operation requiring the HTTP request must be done in the
+`init/2` function, as the Req object will not be available
+after it returns. Websocket sub-protocol selection should
+therefore be done in this function.
-websocket_version = 7 | 8 | 13::
- The version of the Websocket protocol being used.
+The optional `websocket_init/1` callback will be called once
+the connection has been upgraded to Websocket. It can be used
+to perform any required initialization of the handler.
-== Terminate reasons
+Note that the `init/2` function does not run in the same
+process as the Websocket callbacks. Any Websocket-specific
+initialization must be done in `websocket_init/1`.
-The following values may be received as the terminate reason
-in the optional `terminate/3` callback.
+The `websocket_handle/2` callback will be called for every
+frame received. The `websocket_info/2` callback will be
+called for every Erlang message received.
+
+All three Websocket callbacks may send one or more frames
+back to the client (by returning a `reply` tuple) or terminate
+the connection (by sending a `close` frame or returning a `stop`
+tuple).
+
+The optional `terminate/3` callback will ultimately be called
+with the reason for the termination of the connection. This
+callback is common to all handlers. Note that Websocket has
+no concept of requests so it sets the second argument to
+undefined.
+
+Cowboy will terminate the process right after closing the
+Websocket connection. This means that there is no need to
+perform any cleanup in the `terminate/3` callback.
+
+The following terminate reasons are defined for Websocket
+connections:
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.
+ 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.
+ The remote endpoint closed the connection without giving any
+ further details.
{remote, Code, Payload}::
- The remote endpoint closed the connection with the given
- `Code` and `Payload` as the reason.
+ The remote endpoint closed the connection with the given
+ `Code` and `Payload` as the reason.
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`.
+ The connection has been closed due to inactivity. The timeout
+ value can be configured from `init/2`.
{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.
{error, badencoding}::
- A text frame was sent by the client with invalid encoding. All
- text frames must be valid UTF-8.
+ A text frame was sent by the client with invalid encoding. All
+ text frames must be valid UTF-8.
{error, badframe}::
- A protocol error has been detected.
+ A protocol error has been detected.
{error, closed}::
- The socket has been closed brutally without a close frame being
- received first.
+ The socket has been closed brutally without a close frame being
+ received first.
{error, Reason}::
- A socket error ocurred.
-
-== Callbacks
-
-=== websocket_handle(InFrame, State) -> Ret
-
-[source,erlang]
-----
-Ret = {ok, State}
- | {ok, State, hibernate}
- | {reply, OutFrame | [OutFrame], State}
- | {reply, OutFrame | [OutFrame], State, hibernate}
- | {stop, State}
-
-InFrame = {text | binary | ping | pong, binary()}
-State = any()
-OutFrame = cow_ws:frame()
-----
-
-Handle the data received from the Websocket connection.
-
-This function will be called every time data is received
-from the Websocket connection.
-
-The `stop` return value can be used to close the
-connection. A close reply will also result in the connection
-being closed.
-
-The `hibernate` option will hibernate the process until
-it receives new data from the Websocket connection or an
-Erlang message.
-
-=== websocket_info(Info, State) -> Ret
-
-[source,erlang]
-----
-Ret = {ok, State}
- | {ok, State, hibernate}
- | {reply, OutFrame | [OutFrame], State}
- | {reply, OutFrame | [OutFrame], State, hibernate}
- | {stop, State}
-
-Info = any()
-State = any()
-OutFrame = cow_ws:frame()
-----
+ A socket error ocurred.
-Handle the Erlang message received.
+== Changelog
-This function will be called every time an Erlang message
-has been received. The message can be any Erlang term.
+* *2.0*: The Req object is no longer passed to Websocket callbacks.
+* *2.0*: The callback `websocket_terminate/3` was removed in favor of `terminate/3`.
+* *1.0*: Protocol introduced.
-The `stop` return value can be used to close the
-connection. A close reply will also result in the connection
-being closed.
+== See also
-The `hibernate` option will hibernate the process until
-it receives another message or new data from the Websocket
-connection.
+link:man:cowboy(7)[cowboy(7)],
+link:man:cowboy_http(3)[cowboy_http(3)],
+link:man:cowboy_http2(3)[cowboy_http2(3)]