how to organize gorilla mux routes?

i am using Gorilla Mux for writing a REST API and i am having trouble organizing my routes, currently all of my routes are defined in the main.go file like this

//main.go
package main

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

func main() {

    router := mux.NewRouter().StrictSlash(true)

    router.HandleFunc("/hello", func(res http.ResponseWriter, req *http.Request) {
        fmt.Fprintln(res, "Hello")
    })

    router.HandleFunc("/user", func(res http.ResponseWriter, req *http.Request) {
        fmt.Fprintln(res, "User")
    })

    router.HandleFunc("/route2", func(res http.ResponseWriter, req *http.Request) {
        fmt.Fprintln(res, "Route2")
    })

    router.HandleFunc("/route3", func(res http.ResponseWriter, req *http.Request) {
        fmt.Fprintln(res, "Route3")
    })

    // route declarations continue like this

    http.ListenAndServe(":1128", router)

}

so what i want to do is take out and split this route declaration into multiple files, how would i go about doing that? thanks in advance.

Solution

What about something like this ?

//main.go
package main

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

func main() {

    router := mux.NewRouter().StrictSlash(true)

    router.HandleFunc("/hello", HelloHandler)
    router.HandleFunc("/user", UserHandler)
    router.HandleFunc("/route2", Route2Handler)
    router.HandleFunc("/route3", Route3Handler)
    // route declarations continue like this

    http.ListenAndServe(":1128", router)

}

func HelloHandler(res http.ResponseWriter, req *http.Request) {
    fmt.Fprintln(res, "Hello")
}

func UserHandler(res http.ResponseWriter, req *http.Request) {
    fmt.Fprintln(res, "User")
}

func Route2Handler(res http.ResponseWriter, req *http.Request) {
    fmt.Fprintln(res, "Route2")
}

func Route3Handler(res http.ResponseWriter, req *http.Request) {
    fmt.Fprintln(res, "Route3")
}

That way you can put your handlers in other files, or even other packages.

If you endup with additionnal dependencies like a database, you can even avoid the need of the global var using a constructor trick:

//main.go

func main() {
    db := sql.Open(…)

    //...

    router.HandleFunc("/hello", NewHelloHandler(db))

    //...
}

func NewHelloHandler(db *sql.DB) func(http.ResponseWriter, *http.Request) {
    return func(res http.ResponseWriter, req *http.Request) {
        // db is in the local scope, and you can even inject it to test your
        // handler
        fmt.Fprintln(res, "Hello")
    }
}