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-Reading the request body
-========================
-
-The Req object also allows you to read the request body.
-
-Because the request body can be of any size, all body
-reading operations will only work once, as Cowboy will
-not cache the result of these operations.
-
-Cowboy will not attempt to read the body until you do.
-If handler execution ends without reading it, Cowboy
-will simply skip it.
-
-Cowboy provides different ways to read the request body.
-You can read it directly, stream it, but also read and
-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
-----------------------
-
-You can check whether a body was sent with the request.
-
-``` erlang
-cowboy_req:has_body(Req).
-```
-
-It will return `true` if there is a request body, and
-`false` otherwise.
-
-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
--------------------
-
-You can obtain the body length if it was sent with the
-request.
-
-``` erlang
-{Length, Req2} = cowboy_req:body_length(Req).
-```
-
-The value returned will be `undefined` if the length
-couldn't be figured out from the request headers. If
-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
-----------------
-
-You can read the whole body directly in one call.
-
-``` 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
-{ok, Body, Req2} = cowboy_req:body(Req, [{length, 100000000}]).
-```
-
-You can also disable it.
-
-``` erlang
-{ok, Body, Req2} = cowboy_req:body(Req, [{length, infinity}]).
-```
-
-It is recommended that you do not disable it for public
-facing websites.
-
-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
-------------------
-
-You can stream the request body by chunks.
-
-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
-body_to_console(Req) ->
- case cowboy_req:body(Req) of
- {ok, Data, Req2} ->
- io:format("~s", [Data]),
- Req2;
- {more, Data, Req2} ->
- 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
--------------------------
-
-You can control the rate of data transmission by setting
-options when calling body functions. This applies not only
-to the functions described in this chapter, but also to
-the multipart functions.
-
-The `read_length` option defines the maximum amount of data
-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
------------------------------
-
-Cowboy will by default decode the chunked transfer-encoding
-if any. It will not decode any content-encoding by default.
-
-The first time you call a body function you can set the
-`transfer_decode` and `content_decode` options. If the body
-was already started being read these options are simply
-ignored.
-
-The following example shows how to set both options.
-
-``` erlang
-{ok, Req2} = cowboy_req:body(Req, [
- {transfer_decode, fun transfer_decode/2, TransferState},
- {content_decode, fun content_decode/1}
-]).
-```
-
-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
-{ok, KeyValues, Req2} = cowboy_req:body_qs(Req).
-```
-
-You can then retrieve an individual value from that list.
-
-``` erlang
-{_, Lang} = lists:keyfind(lang, 1, KeyValues).
-```
-
-You should not attempt to match on the list as the order
-of the values is undefined.
-
-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}]).
-```