How do I split URLS in multiple Files using gorilla/mux?

Question

My directory structure looks like this:

myapp/
|
+-- moduleX
|      |
|      +-- views.go
|
+-- start.go

The app gets started with start.go and from there I configure all the routes and import the handlers from moduleX/views.go like this:

package main

import (
    "net/http"
    "github.com/gorilla/mux"
    "myapp/moduleX"
)

func main() {
    r := mux.NewRouter()
    http.Handle("/static/", http.StripPrefix("/static/", http.FileServer(http.Dir("./templates/static/"))))
    r.HandleFunc("/", moduleX.SomePostHandler).Methods("POST")
    r.HandleFunc("/", moduleX.SomeHandler)
    http.Handle("/", r)
    http.ListenAndServe(":8080", nil)
}

Now I want to add more modules and ask myself if (and how) it is possible to define the urls in the module in a urls.go file and somehow "import" them in start.go. Specifically I want start.go to know all the URLs in all the somemodule/urls.go files with just one import or some kind of a module.GetURLs function.

Answer 1

Why not get the handlers to insert themselves into the routes table?

If you're defining each handler in its own go file, use the `init()` func for each file to add the handler to a global routing table

So something like:

---

main.go:

type route{
    method string
    path string
    handler func(w http.ResponseWriter, r *http.Request)
}
var routes = make([]route,0)

func registerRoute(r route){
    routes = append(routes,r)
}

func server(){
    r := mux.NewRouter()
    http.Handle("/static/", http.StripPrefix("/static/", http.FileServer(http.Dir("./templates/static/"))))
    // set up all the registered routes
    for _, rt = range(routes){
        r.HandleFunc(rt.path,rt.handler).Methods(rt.Method)
    }
    // and there's usually some other stuff that needs to go in here

    //before we finally serve the content here!
    http.ListenAndServe(":8080", nil)
}

---

yourmodule.go:

func init(){
    r = route{
        method="GET",
        path="/yourmodule/path/whatever",
        handler=yourHandlerFunc,
    }
    registerRoute(r)
}

func yourHandlerFunc(w http.ResponseWriter, r *http.Request){
    //awesome web stuff goes here
}

---

init() gets called for each file in a package before execution of the package main() so you can be sure that all your handlers will be registered before you kick the server off.

This pattern can be extended to allow for more tricksy registration gubbins to happen as needed, since the modules themselves are now in charge of their own registration, instead of trying to cram all the special cases into one registration func