From faca7866ed1c59cd41e11fcfc5a9f95378380497 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Lo=C3=AFc=20Hoguin?= Date: Sat, 5 Nov 2016 14:17:30 +0200 Subject: Partially update manual for the cowboy_req Only the access functions have been modified so far. --- doc/src/manual/cowboy_req.header.asciidoc | 74 +++++++++++++++++++++++++++++++ 1 file changed, 74 insertions(+) create mode 100644 doc/src/manual/cowboy_req.header.asciidoc (limited to 'doc/src/manual/cowboy_req.header.asciidoc') diff --git a/doc/src/manual/cowboy_req.header.asciidoc b/doc/src/manual/cowboy_req.header.asciidoc new file mode 100644 index 0000000..e16b902 --- /dev/null +++ b/doc/src/manual/cowboy_req.header.asciidoc @@ -0,0 +1,74 @@ += cowboy_req:header(3) + +== Name + +cowboy_req:header - HTTP header + +== Description + +[source,erlang] +---- +header(Name :: binary(), Req) -> header(Name, Req, undefined) +header(Name :: binary(), Req, Default) -> binary() | Default + +Req :: cowboy_req:req() +---- + +Return the value for the given HTTP header. + +The header name must be given as a lowercase binary string. +While header names are case insensitive, Cowboy requires them +to be given as lowercase to function properly. + +Headers can also be obtained using pattern matching: + +[source,erlang] +---- +#{headers := #{Name := Value}} = Req. +---- + +Note that this snippet will crash if the header is missing. + +== Arguments + +Name:: + +Desired HTTP header name as a binary string. + +Req:: + +The Req object. + +Default:: + +Default value returned when the header is missing. + +== Return value + +The header value is returned as a binary string. When the +header is missing, the default argument is returned. + +== Changelog + +* *2.0*: Only the header value is returned, it is no longer wrapped in a tuple. +* *1.0*: Function introduced. + +== Examples + +.Get the accept header +[source,erlang] +---- +Accept = cowboy_req:header(<<"accept">>, Req). +---- + +.Get the content-length header with a default value +[source,erlang] +---- +Length = cowboy_req:header(<<"content-length">>, Req, <<"0">>). +---- + +== See also + +link:man:cowboy_req(3)[cowboy_req(3)], +link:man:cowboy_req:headers(3)[cowboy_req:headers(3)], +link:man:cowboy_req:parse_header(3)[cowboy_req:parse_header(3)] -- cgit v1.2.3