From a27296b34d3dc2481f0e3c013b7548690db26b01 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Lo=C3=AFc=20Hoguin?= Date: Fri, 18 Jan 2013 19:51:00 +0100 Subject: Document loop handlers in the guide --- guide/loop_handlers.md | 20 ++++++++++++++------ guide/toc.md | 1 - 2 files changed, 14 insertions(+), 7 deletions(-) (limited to 'guide') diff --git a/guide/loop_handlers.md b/guide/loop_handlers.md index 41f9e76..64cf80a 100644 --- a/guide/loop_handlers.md +++ b/guide/loop_handlers.md @@ -16,15 +16,23 @@ While the same can be accomplished using plain HTTP handlers, it is recommended to use loop handlers because they are well-tested and allow using built-in features like hibernation and timeouts. -Callbacks ---------- - -@todo Describe the callbacks. - Usage ----- -@todo Explain how to use them. +Loop handlers are used for requests where a response might not +be immediately available, but where you would like to keep the +connection open for a while in case the response arrives. The +most known example of such practice is known as long-polling. + +Loop handlers can also be used for requests where a response is +partially available and you need to stream the response body +while the connection is open. The most known example of such +practice is known as server-sent events. + +Loop handlers essentially wait for one or more Erlang messages +and feed these messages to the `info/3` callback. It also features +the `init/3` and `terminate/2` callbacks which work the same as +for plain HTTP handlers. The following handler waits for a message `{reply, Body}` before sending a response. If this message doesn't arrive within 60 diff --git a/guide/toc.md b/guide/toc.md index b6675e6..528f8c6 100644 --- a/guide/toc.md +++ b/guide/toc.md @@ -21,7 +21,6 @@ Cowboy User Guide * Usage * [Loop handlers](loop_handlers.md) * Purpose - * Callbacks * Usage * [Websocket handlers](ws_handlers.md) * Purpose -- cgit v1.2.3