From faefb634de2874cafaf7f2d7fb7d4f8eab9019a9 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Lo=C3=AFc=20Hoguin?= Date: Wed, 27 Jun 2018 10:29:49 +0200 Subject: Document cowboy_req:stream_events/3 --- doc/src/manual/cowboy_req.stream_events.asciidoc | 101 +++++++++++++++++++++++ 1 file changed, 101 insertions(+) create mode 100644 doc/src/manual/cowboy_req.stream_events.asciidoc (limited to 'doc/src/manual/cowboy_req.stream_events.asciidoc') diff --git a/doc/src/manual/cowboy_req.stream_events.asciidoc b/doc/src/manual/cowboy_req.stream_events.asciidoc new file mode 100644 index 0000000..72f3c3b --- /dev/null +++ b/doc/src/manual/cowboy_req.stream_events.asciidoc @@ -0,0 +1,101 @@ += cowboy_req:stream_events(3) + +== Name + +cowboy_req:stream_events - Stream events + +== Description + +[source,erlang] +---- +stream_events(Events, IsFin, Req :: cowboy_req:req()) -> ok + +Events :: Event | [Event] +IsFin :: fin | nofin + +Event :: #{ + comment => iodata(), + data => iodata(), + event => iodata() | atom(), + id => iodata(), + retry => non_neg_integer() +} +---- + +Stream events. + +This function should only be used for `text/event-stream` +responses when using server-sent events. Cowboy will +automatically encode the given events to their text +representation. + +This function may be called as many times as needed after +initiating a response using the +link:man:cowboy_req:stream_reply(3)[cowboy_req:stream_reply(3)] +function. + +The second argument indicates if this call is the final +call. Use the `nofin` value until you know no more data +will be sent. The final call should use `fin` (possibly +with an empty data value) or be a call to the +link:man:cowboy_req:stream_trailers(3)[cowboy_req:stream_trailers(3)] +function. + +Note that not using `fin` for the final call is not an +error; Cowboy will take care of it when the request +handler terminates if needed. Depending on the resource +it may however be more efficient to do it as early as +possible. + +You do not need to handle HEAD requests specifically as +Cowboy will ensure no data is sent when you call this function. + +== Arguments + +Events:: + +Events to be sent. All fields are optional. + +IsFin:: + +A flag indicating whether this is the final piece of data +to be sent. + +Req:: + +The Req object. + +== Return value + +The atom `ok` is always returned. It can be safely ignored. + +== Changelog + +* *2.5*: Function introduced. + +== Examples + +.Stream events +[source,erlang] +---- +Req = cowboy_req:stream_reply(200, #{ + <<"content-type">> => <<"text/event-stream">> +}, Req0), +cowboy_req:stream_events(#{ + id => <<"comment-123">>, + event => <<"add_comment">>, + data => <<"Hello,\n\nI noticed something wrong in ...">> +}, nofin, Req), +timer:sleep(1000), +cowboy_req:stream_events(#{ + event => <<"debug">>, + data => io_lib:format("An error occurred: ~p~n", [Error]) +}, fin, Req). +---- + +== See also + +link:man:cowboy_req(3)[cowboy_req(3)], +link:man:cowboy_req:stream_reply(3)[cowboy_req:stream_reply(3)], +link:man:cowboy_req:stream_body(3)[cowboy_req:stream_body(3)], +link:man:cowboy_req:stream_trailers(3)[cowboy_req:stream_trailers(3)] -- cgit v1.2.3