Let's Go › Configuration and error handling › Isolating the application routes
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Chapter 3.5.

Isolating the application routes

While we’re refactoring our code there’s one more change worth making.

Our main() function is beginning to get a bit crowded, so to keep it clear and focused I’d like to move the route declarations for the application into a standalone routes.go file, like so:

$ cd $HOME/code/snippetbox
$ touch cmd/web/routes.go
File: cmd/web/routes.go
package main

import "net/http"

// The routes() method returns a servemux containing our application routes.
func (app *application) routes() *http.ServeMux {
    mux := http.NewServeMux()

    fileServer := http.FileServer(http.Dir("./ui/static/"))
    mux.Handle("/static/", http.StripPrefix("/static", fileServer))

    mux.HandleFunc("/", app.home)
    mux.HandleFunc("/snippet/view", app.snippetView)
    mux.HandleFunc("/snippet/create", app.snippetCreate)

    return mux
}

We can then update the main.go file to use this instead:

File: cmd/web/main.go
package main

...

func main() {
    addr := flag.String("addr", ":4000", "HTTP network address")
    
    flag.Parse()

    infoLog := log.New(os.Stdout, "INFO\t", log.Ldate|log.Ltime)
    errorLog := log.New(os.Stderr, "ERROR\t", log.Ldate|log.Ltime|log.Lshortfile)

    app := &application{
        errorLog: errorLog,
        infoLog:  infoLog,
    }

    srv := &http.Server{
        Addr:     *addr,
        ErrorLog: errorLog,
        // Call the new app.routes() method to get the servemux containing our routes.
        Handler: app.routes(),
    }

    infoLog.Printf("Starting server on %s", *addr)
    err := srv.ListenAndServe()
    errorLog.Fatal(err)
}

This is quite a bit neater. The routes for our application are now isolated and encapsulated in the app.routes() method, and the responsibilities of our main() function are limited to: