Adding httprouter dependency to manage endpoints. Adding our routes to routes.go file facilitating endpoints management and adding POST /v1/movies and GET /v1/movies/:id endpoints. Updating main.go file removing ServeMux and add httprouter instead in app structure. Creating movies.go file to manage create and show movie endpoint.

cmd/api/main.go

@@ -57,13 +57,6 @@ func main() {
 		logger: logger,
 	}
 
-	/*
-		Declare a new servemux and add a /v1/healthcheck route which dispatches requests
-		to the healthcheckHandler method.
-	*/
-	mux := http.NewServeMux()
-	mux.HandleFunc("/v1/healthcheck", app.healthcheckHandler)
-
 	/*
 		Declare a HTTP server which listens on the port provided in the config struct,
 		uses the servemux we created above as the handler, has some sensible timeout
@@ -71,7 +64,7 @@ func main() {
 	*/
 	srv := &http.Server{
 		Addr:         fmt.Sprintf(":%d", cfg.port),
-		Handler:      mux,
+		Handler:      app.routes(),
 		IdleTimeout:  time.Minute,
 		ReadTimeout:  5 * time.Second,
 		WriteTimeout: 10 * time.Second,

cmd/api/movies.go

@@ -0,0 +1,40 @@
+package main
+
+import (
+	"fmt"
+	"github.com/julienschmidt/httprouter"
+	"net/http"
+	"strconv"
+)
+
+// "POST /v1/movies" endpoint.
+func (app *application) createMovieHandler(w http.ResponseWriter, r *http.Request) {
+	fmt.Fprintln(w, "create a new movie")
+}
+
+// "GET /v1/movies/:id"
+func (app *application) showMovieHandler(w http.ResponseWriter, r *http.Request) {
+	/*
+		When httprouter is parsing a request, any interpolated URL parameters will be
+		stored in the request context. We can use the ParamsFromContext() function to
+		retrieve a slice containing these parameter names and values.
+	*/
+	params := httprouter.ParamsFromContext(r.Context())
+
+	/*
+		We can then use the ByName() method to get the value of the "id" parameter from
+		the slice. In our project all movies will have a unique positive integer ID, but
+		the value returned by ByName() is always a string. So we try to convert it to a
+		base 1° integer (with a bit size of 64). If the parameter couldn't be converted,
+		or is less than 1, we know the ID is invalid so we use the http.NotFound()
+		func to return a 404 Not Found Response.
+	*/
+	id, err := strconv.ParseInt(params.ByName("id"), 10, 64)
+	if err != nil || id < 1 {
+		http.NotFound(w, r)
+		return
+	}
+
+	// Otherwise, interpolate the movie ID in a placeholder response.
+	fmt.Fprintf(w, "show the details of movie %d\n", id)
+}

cmd/api/routes.go

@@ -0,0 +1,24 @@
+package main
+
+import (
+	"github.com/julienschmidt/httprouter"
+	"net/http"
+)
+
+func (app *application) routes() http.Handler {
+	// Initialize a new httprouter router instance
+	router := httprouter.New()
+
+	/*
+		Register the relevant methods, URL patterns and handler functions for our
+		endpoints using the HandlerFunc() method. Note that http.MethodGet and
+		http.MethodPost are constants which equate to the strings "GET" and "POST"
+		respectively.
+	*/
+	router.HandlerFunc(http.MethodGet, "/v1/healthcheck", app.healthcheckHandler)
+	router.HandlerFunc(http.MethodPost, "/v1/movies", app.createMovieHandler)
+	router.HandlerFunc(http.MethodGet, "/v1/movies/:id", app.showMovieHandler)
+
+	// Return the httprouter instance.
+	return router
+}