The cowboy_sub_protocol behaviour defines the interface used by modules that implement a protocol on top of HTTP.
Types
None.
Callbacks
upgrade(Req, Env, Handler, Opts) -> {ok, Req, Env} | {suspend, Module, Function, Args} | {halt, Req} | {error, StatusCode, Req}
Types:
- Req = cowboy_req:req()
- Env = env()
- Handler = module()
- Opts = any()
- Module = module()
- Function = atom()
- Args = [any()]
- StatusCode = cowboy:http_status()
Upgrade the protocol.
Please refer to the cowboy_middleware manual for a description of the return values.
