better handling of method not allowed

[skaes]

No description provided.

[roccoblues]

I'm not sure if this is correct. If I setup a route like this:

gorilla.ActionName(r.HandleFunc("/image/{folder}/{file}", app.publicHandler).Methods("GET", "HEAD"), "Image#public")

Will the methodNotAllowed handlers added also have the action name Image#public?
What if I call request.ChangeAction in my handler? Then the methodNotAllowed handler will have a different action name for sure.

Definitely needs some test. ;-)

Also, since this is gorilla/mux specific we should still add something like #10 to support other routers.

[skaes]

The idea of this code was to make the system behave as if the handler for a given route would accept all HTTP methods initially and then report 405 for the methods it does not really support. This works fine when template paths are unique, but yields confusing results when there are multiple routes with the same template path, but different handlers and action names. In that case, the current implementation will pick the name of the first route with the given template path.

Example:

gorilla.ActionName(router.Path("/users").Methods("GET").HandlerFunc(...), "Users#index")
gorilla.ActionName(router.Path("/users").Methods("POST").HandlerFunc(...), "Users#create")

This will lead to one additional route being installed that one could have written manually as

gorilla.ActionName(router.Path("/users").Methods("PUT", "DELETE", "HEAD", "OPTIONS", "PATCH").HandlerFunc(methodNotAllowed), "Users#index")

Maybe a better approach would be to do the equivalent of

gorilla.ActionName(router.Path("/users").Methods("PUT", "DELETE", "HEAD", "OPTIONS", "PATH").HandlerFunc(methodNotAllowed), "Users#methodNotAllowed")

The goal was to preserve some information on which part of the application was the intended receiver of the request and make this visible in the logjam UI. In this case: the part that deals with users.

However, I'm no longer sure the extra code complexity is worth pursuing this further, especially as the number of method not allowed requests for a given application is usually very low and one can easily debug the few requests under a single action name (like System#methodNotAllowed).