fix handler

handler.go

@@ -0,0 +1,35 @@
+package main
+
+import (
+	"encoding/json"
+	"net/http"
+)
+
+type handler struct{}
+
+func (h *handler) getRoot() func(w http.ResponseWriter, r *http.Request) {
+	return func(w http.ResponseWriter, r *http.Request) {
+		{
+			resp, err := http.Get("https://lottery-dot-tenntenn-samples.appspot.com/available_lotteries")
+			if err != nil {
+				const status = http.StatusInternalServerError
+				http.Error(w, http.StatusText(status), status)
+				return
+			}
+			defer resp.Body.Close()
+
+			var lotteries []*Lottery
+			if err := json.NewDecoder(resp.Body).Decode(&lotteries); err != nil {
+				const status = http.StatusInternalServerError
+				http.Error(w, http.StatusText(status), status)
+				return
+			}
+
+			if err := listTmpl.Execute(w, lotteries); err != nil {
+				const status = http.StatusInternalServerError
+				http.Error(w, http.StatusText(status), status)
+				return
+			}
+		}
+	}
+}

main.go

@@ -32,28 +32,9 @@ func main() {
 		panic(err)
 	}
 
-	http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
-		resp, err := http.Get("https://lottery-dot-tenntenn-samples.appspot.com/available_lotteries")
-		if err != nil {
-			const status = http.StatusInternalServerError
-			http.Error(w, http.StatusText(status), status)
-			return
-		}
-		defer resp.Body.Close()
-
-		var lotteries []*Lottery
-		if err := json.NewDecoder(resp.Body).Decode(&lotteries); err != nil {
-			const status = http.StatusInternalServerError
-			http.Error(w, http.StatusText(status), status)
-			return
-		}
+	h := &handler{}
 
-		if err := listTmpl.Execute(w, lotteries); err != nil {
-			const status = http.StatusInternalServerError
-			http.Error(w, http.StatusText(status), status)
-			return
-		}
-	})
+	http.HandleFunc("/", h.getRoot())
 
 	http.HandleFunc("/purchase_page", func(w http.ResponseWriter, r *http.Request) {
 		resp, err := http.Get("https://lottery-dot-tenntenn-samples.appspot.com/lottery?id=" + r.FormValue("id"))