added a json handler

handlers.go

@@ -14,6 +14,13 @@ type prob struct {
 	Last      int
 }
 
+type JsonHandler func(http.ResponseWriter, *http.Request)
+
+func (h JsonHandler) ServeHTTP(w http.ResponseWriter, req *http.Request) {
+	w.Header().Set("Content-Type", "application/json")
+    h(w, req)
+}
+
 func problem(w http.ResponseWriter, req *http.Request) {
 	operation := "+"
 	if r := rand.Intn(2); r == 0 {

main.go

@@ -21,8 +21,8 @@ func main() {
 	flag.Parse()
 	http.Handle("/",
 		http.FileServer(http.Dir(*static_files)))
-    http.HandleFunc("/api/v0/attempt/", attempt)
-    http.HandleFunc("/api/v0/problem/", problem)
+    http.HandleFunc("/api/v0/attempt/", JsonHandler(attempt))
+    http.Handle("/api/v0/problem/", JsonHandler(problem))
 	if err := http.ListenAndServe(*addr, nil); err != nil {
 		log.Fatal("ListenAndServe:", err)
 	}

static/math.js

@@ -7,7 +7,7 @@ function update_board(f, o, s, score) {
 
 function new_problem() {
     $.get("/api/v0/problem/", function(d) {
-        update_board(d["first"], d["operation"], d["second"], d["score"]);
+        update_board(d["First"], d["Operation"], d["Second"], d["Score"]);
         $("#answer").val("");
     })
 }