This module defines the cowboy_sub_protocol behaviour.
Required callback functions: upgrade/4.
Behaviour for sub protocols.
Only one function needs to be implemented, upgrade/4. It receives the Req, the environment, the handler that the request has been routed to and the handler's options. It acts exactly the same as a middleware, so returns the same values a middleware's execute/2.
Once the sub protocol has processed the request it should add the result to the environment. This is done by adding the tuple {result, Value} to the environment list. To continue handling requests on the current connection the Value should be the atom ok. Any other value will prevent the processing of subsequent requests.
upgrade/4 will be called when a handler's init/3 returns {upgrade, protocol, Module}, where Module is the module of the sub protocol.Generated by EDoc, Aug 16 2014, 11:28:17.