Document Usage Of Router.NotFoundHandler about mux HOT 5 CLOSED

Please add 404 code to https://github.com/gorilla/mux and http://www.gorillatoolkit.org/pkg/mux pages it took a while to look for it!

mux.NewRouter()
r.NotFoundHandler = http.HandlerFunc(func (w http.ResponseWriter, req *http.Request) {
                 // Handle 404
}
from mux.

for anybody googled that; a complete example to copy and paste

   ...	
   router := mux.NewRouter()
   router.NotFoundHandler = Handle404()
  ...
}

// Handle404 ...
func Handle404() http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		json.
		    NewEncoder(w).
		    Encode(
		        HTTPError{
			    Code:    string(http.StatusNotFound),
			    Message: http.StatusText(http.StatusNotFound),
			})
	})
}

from mux.

It's also missing from the tests, which is where I usually look for usage when it's not documented.

In case anyone else Googles this and needs it:

func Handle404(w http.ResponseWriter, r *http.Request) {
    // Handle 404
}

r := mux.NewRouter()
r.NotFoundHandler = Handle404

from mux.

@evantbyrne @zikes What do you think is missing at the moment? It's documented as part of the Router type:

type Router struct {
    // Configurable Handler to be used when no route matches.
    NotFoundHandler http.Handler

    // If true, do not clear the request context after handling the request
    KeepContext bool
    // contains filtered or unexported fields
}

If you think it should be included in the main body of the documentation, submit a PR (following the format for code samples) ;)

from mux.

I have started adding some example tests (not pushed yet). Would probably be nice to have one of those.

from mux.