Using intermediate handler function to route requests

Question

I was thinking of ways to do routing with the standard library. Is it valid to have a handler function that will call other handler functions depending on the request type? e.g.

func main() {
    m := http.NewServeMux()
    m.HandleFunc("/books", books)
    // ...
}

func books(w http.ResponseWriter, r *http.Request) {
    switch r.Method {
        case "GET":
            getBooks(w, r)
        case "POST":
            createBook(w, r)
    }
}

Is this good practice? I didn't want to declare a custom handler since I find functions to be a bit cleaner.

Answer 1

Yes, this is perfectly valid; handlers are just functions so there is no reason it shouldn't be. In fact, this is how middleware is usually implemented.

There is nothing "magic" about handler functions at all. As long as you're writing to the correct file descriptor (w http.ResponseWriter) anything goes.

That doesn't mean that using this pattern is necessarily a good idea for all applications – routing libraries exist for a reason – but for smaller programs it will work just fine.