Get parameters through standard http.Handler

[bodokaiser]

Hello,

you write yourself that there is no efficient way to retrieve parameters without providing a third parameter.

I thought of four possible ways which we see partly in other routers:

1. Save parameter in request.URL.Query() pat
2. Save match with request and resolve it extra gorilla/mux
3. Rerun route matcher on url to extract parameter.

The third one would require another extraction of the route parameter but as it is optional and does not require any extra cache layer I think it could be still efficient (if this is your main concern).

Best,
Bo

[julienschmidt]

1. Also requires additional parsing (and allocations)
2. Allocations + a synchronization hot spot
3. Does the work twice

[bodokaiser]

The last idea I have is using type casting on *url.URL as it is done with http.Flusher:

f, ok := w.(http.Flusher)

or with the url:

url, ok := request.URL.(httprouter.URL)

if ok {
    fmt.Printf("param: %s\n", url.Param("id"))
}

This could also be hidden somehow in a helper function:

id, err := httprouter.Param(r, "id")

What do you think?