lets-go:2.6 refactor app to go "Developing Modules" pattern

https://go.dev/doc/modules/layout#server-project

snippetbox/cmd/web/handlers.go

@@ -1,8 +1,9 @@
 package main
 
 import (
-	"log"
+	"fmt"
 	"net/http"
+	"strconv"
 )
 
 // home ...
@@ -16,7 +17,13 @@ func home(w http.ResponseWriter, r *http.Request)  {
 
 // snippetView ...
 func snippetView(w http.ResponseWriter, r *http.Request)  {
-	w.Write([]byte("It's a snippet!"))
+	id, err := strconv.Atoi(r.URL.Query().Get("id"))
+	if err != nil || id < 1 {
+		http.NotFound(w, r)
+		return
+	}
+
+	fmt.Fprintf(w, "It's snippet id: %d", id)
 }
 
 // snippetCreate ...
@@ -30,15 +37,3 @@ func snippetCreate(w http.ResponseWriter, r *http.Request)  {
 
 	w.Write([]byte("Creating a snippet!"))
 }
-
-// main it's the snippetbox webapp
-func main() {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/", home)
-	mux.HandleFunc("/snippet/view", snippetView)
-	mux.HandleFunc("/snippet/create", snippetCreate)
-
-	log.Print("starting a server on :4000")
-	err := http.ListenAndServe(":4000", mux)
-	log.Fatal(err)
-}

snippetbox/cmd/web/main.go

@@ -0,0 +1,18 @@
+package main
+
+import (
+	"log"
+	"net/http"
+)
+
+// main it's the snippetbox webapp
+func main() {
+	mux := http.NewServeMux()
+	mux.HandleFunc("/", home)
+	mux.HandleFunc("/snippet/view", snippetView)
+	mux.HandleFunc("/snippet/create", snippetCreate)
+
+	log.Print("starting a server on :4000")
+	err := http.ListenAndServe(":4000", mux)
+	log.Fatal(err)
+}