Move request handlers out of main.go

api.go

@@ -0,0 +1,32 @@
+package main
+
+import (
+	"net/http"
+)
+
+func CreateApiHandler(settings *TranslateSettings) func(w http.ResponseWriter, req *http.Request) {
+	return func(w http.ResponseWriter, req *http.Request) {
+		from := req.FormValue("from")
+		if from == "" {
+			writeError(w, 400, "'from' field is missing")
+			return
+		}
+		to := req.FormValue("to")
+		if to == "" {
+			writeError(w, 400, "'to' field is missing")
+			return
+		}
+		text := req.FormValue("text")
+		if text == "" {
+			writeError(w, 400, "'text' field is missing")
+			return
+		}
+
+		translation, err := Translate(settings, from, to, text)
+		if err != nil {
+			writeError(w, 500, err)
+		}
+
+		w.Write([]byte(translation))
+	}
+}

main.go

@@ -17,7 +17,6 @@
 package main
 
 import (
-	"fmt"
 	"html/template"
 	"log"
 	"net/http"
@@ -58,55 +57,8 @@ func main() {
 
 	r := mux.NewRouter()
 
-	r.HandleFunc("/", func(w http.ResponseWriter, req *http.Request) {
-		if req.Method == "GET" {
-			tmpl.ExecuteTemplate(w, "index", nil)
-			return
-		}
-
-		from := req.FormValue("from")
-		to := req.FormValue("to")
-		text := req.FormValue("text")
-
-		translation, err := Translate(&settings, from, to, text)
-		if err != nil {
-			writeError(w, 500, err)
-		}
-
-		type indexPageData struct {
-			From        string
-			To          string
-			Text        string
-			Translation string
-		}
-
-		tmpl.ExecuteTemplate(w, "index", indexPageData{from, to, text, translation})
-	}).Methods("GET", "POST")
-
-	r.HandleFunc("/api", func(w http.ResponseWriter, req *http.Request) {
-		from := req.FormValue("from")
-		if from == "" {
-			writeError(w, 400, "'from' field is missing")
-			return
-		}
-		to := req.FormValue("to")
-		if to == "" {
-			writeError(w, 400, "'to' field is missing")
-			return
-		}
-		text := req.FormValue("text")
-		if text == "" {
-			writeError(w, 400, "'text' field is missing")
-			return
-		}
-
-		translation, err := Translate(&settings, from, to, text)
-		if err != nil {
-			writeError(w, 500, err)
-		}
-
-		w.Write([]byte(translation))
-	}).Methods("POST")
+	r.HandleFunc("/", CreateWebHandler(tmpl, &settings)).Methods("GET", "POST")
+	r.HandleFunc("/api", CreateApiHandler(&settings)).Methods("POST")
 
 	// Static files
 	fs := http.FileServer(http.Dir(*staticDir))
@@ -115,8 +67,3 @@ func main() {
 	log.Println("Starting on", *bind)
 	log.Fatalln(http.ListenAndServe(*bind, r))
 }
-
-func writeError(w http.ResponseWriter, status int, err interface{}) {
-	w.WriteHeader(status)
-	w.Write([]byte(fmt.Sprintln(err)))
-}

utils.go

@@ -0,0 +1,11 @@
+package main
+
+import (
+	"fmt"
+	"net/http"
+)
+
+func writeError(w http.ResponseWriter, status int, err interface{}) {
+	w.WriteHeader(status)
+	w.Write([]byte(fmt.Sprintln(err)))
+}

web.go

@@ -0,0 +1,33 @@
+package main
+
+import (
+	"html/template"
+	"net/http"
+)
+
+func CreateWebHandler(tmpl *template.Template, settings *TranslateSettings) func(w http.ResponseWriter, req *http.Request) {
+	return func(w http.ResponseWriter, req *http.Request) {
+		if req.Method == "GET" {
+			tmpl.ExecuteTemplate(w, "index", nil)
+			return
+		}
+
+		from := req.FormValue("from")
+		to := req.FormValue("to")
+		text := req.FormValue("text")
+
+		translation, err := Translate(settings, from, to, text)
+		if err != nil {
+			writeError(w, 500, err)
+		}
+
+		type indexPageData struct {
+			From        string
+			To          string
+			Text        string
+			Translation string
+		}
+
+		tmpl.ExecuteTemplate(w, "index", indexPageData{from, to, text, translation})
+	}
+}