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

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.

Solution

EDIT:

To create a group of mux.Route's in one go, you could define a custom type (handler in the example below) and do do something like:

package main

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

type handler struct {
    path    string
    f       http.HandlerFunc
    methods []string
}

func makeHandlers(hs []handler, r *mux.Router) {
    for _, h := range hs {
        if len(h.methods) == 0 {
            r.HandleFunc(h.path, h.f)
        } else {
            r.HandleFunc(h.path, h.f).Methods(h.methods...)
        }
    }
}

// create some example handler functions

func somePostHandler(w http.ResponseWriter, r *http.Request) {
    fmt.Fprint(w, "POST Handler")
}

func someHandler(w http.ResponseWriter, r *http.Request) {
    fmt.Fprint(w, "Normal Handler")
}

func main() {
    //define some handlers
    handlers := []handler{{path: "/", f: somePostHandler, methods: []string{"POST"}}, {path: "/", f: someHandler}}
    r := mux.NewRouter()
    http.Handle("/static/", http.StripPrefix("/static/", http.FileServer(http.Dir("./templates/static/"))))
    // Initialise the handlers
    makeHandlers(handlers, r)
    http.Handle("/", r)
    http.ListenAndServe(":8080", nil)
}

Playground

ORIGINAL ANSWER:

You don't need to import them if they're in the same package.

You can define the URL variables in urls.go, and then the logic in views.go (or another file in package moduleX) as long as they have the same package declaration.

For instance:

// moduleX/urls.go

package moduleX

var (
    urls = []string{"http://google.com/", "http://stackoverflow.com/"}
)

Then:

// moduleX/views.go (or some other file in package moduleX)

package moduleX

func GetUrls() []string {
    return urls
}

Then:

// start.go

package main

import (
    "fmt"
    "myapp/moduleX"
)

func main() {
    for _, url := range moduleX.GetUrls() {
        fmt.Println(url)
    }
}

Or, even easier, just export the variable from the moduleX package by giving it a capitalised name.

For instance:

// moduleX/urls.go

package moduleX

var URLs = []string{"http://google.com/", "http://stackoverflow.com/"}

and then:

// start.go

package main    

import (
    "fmt"
    "myapp/moduleX"
)

func main() {
    for _, url := range moduleX.URLs {
        fmt.Println(url)
    }
}

Have a look at any of the Go source to see how they handle the same problem. A good example is in the SHA512 source where the lengthy variable is stored in sha512block.go and the logic is in sha512.go.