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diff --git a/doc/src/manual/cowboy_req.read_part_body.asciidoc b/doc/src/manual/cowboy_req.read_part_body.asciidoc new file mode 100644 index 0000000..36b21ec --- /dev/null +++ b/doc/src/manual/cowboy_req.read_part_body.asciidoc @@ -0,0 +1,100 @@ += cowboy_req:read_part_body(3) + +== Name + +cowboy_req:read_part_body - Read the current part's body + +== Description + +[source,erlang] +---- +read_part_body(Req :: cowboy_req:req()) + -> read_part_body(Req, #{}) + +read_part_body(Req :: cowboy_req:req(), Opts) + -> {ok, Data :: binary(), Req} + | {more, Data :: binary(), Req} + +Opts :: cowboy_req:read_body_opts() +---- + +Read the body of the current part of the multipart message. + +This function reads the request body and parses it as +multipart. Each parts of a multipart representation have +their own headers and body. This function returns the +body of the current part. Examples of multipart media types +are `multipart/form-data` and `multipart/byteranges`. + +This function reads a chunk of the part's body. A `more` tuple +is returned when more data remains to be read. Call the function +repeatedly until an `ok` tuple is returned to read the entire body. + +Once a part has been read, it can not be read again. + +Once the body has been read, Cowboy sets the content-length +header if it was not previously provided. + +// @todo Limit the maximum size of multipart headers. + +== Arguments + +Req:: + +The Req object. + +Opts:: + +A map of body reading options. Please refer to +link:man:cowboy_req:read_body(3)[cowboy_req:read_body(3)] +for details about each option. ++ +This function uses the same default options as the +link:man:cowboy_req:read_body(3)[cowboy_req:read_body(3)] +function. + +== Return value + +A `more` tuple is returned when there are more data to be read. + +An `ok` tuple is returned when there are no more data to be read. + +The data is always returned as a binary. + +The Req object returned in the tuple must be used for that point +onward. It contains a more up to date representation of the request. +For example it may have an added content-length header once the +body has been read. + +== Changelog + +* *2.0*: Function introduced. Replaces `part_body/1,2`. + +== Examples + +.Read a full part's body +[source,erlang] +---- +stream_body(Req0, Acc) -> + case cowboy_req:read_part_body(Req0) of + {more, Data, Req} -> + stream_body(Req, << Acc/binary, Data/binary >>); + {ok, Data, Req} -> + {ok, << Acc/binary, Data/binary >>, Req} + end. +---- + +.Ensure a part's body is smaller than 64KB +[source,erlang] +---- +{ok, Body, Req} = cowboy_req:read_part_body(Req0, #{length => 64000}). +---- + +== See also + +link:man:cowboy_req(3)[cowboy_req(3)], +link:man:cowboy_req:has_body(3)[cowboy_req:has_body(3)], +link:man:cowboy_req:body_length(3)[cowboy_req:body_length(3)], +link:man:cowboy_req:read_body(3)[cowboy_req:read_body(3)], +link:man:cowboy_req:read_urlencoded_body(3)[cowboy_req:read_urlencoded_body(3)], +link:man:cowboy_req:read_part(3)[cowboy_req:read_part(3)] |