Added semaphore disabling of the form button.

Author: ratnikov

src/form.js

@@ -17,7 +17,33 @@ AjaxResource.Form = function(form, options) {
 
   this._on_save = options.on_save;
 
-  this._semaphore = new AjaxResource.Semaphore();
+  this._semaphore = new AjaxResource.Semaphore(function() {
+    var old_submit_value = null;
+    return {
+      on_unavailable: function() {
+	if (old_submit_value === null) {
+	  self.submit_button().attr("disabled", true);
+
+	  old_submit_value = self.submit_button().val();
+	  self.submit_button().val("Processing...");
+	} else {
+	  // do nothing since it has been disabled
+	}
+      },
+      on_available: function() {
+	if (old_submit_value !== null) {
+	  self.submit_button().val(old_submit_value);
+	  self.submit_button().attr("disabled", false);
+	  old_submit_value = null;
+	} else {
+	  // do nothing since already available
+	}
+      }
+    };
+  }());
+
+  // make sure the submit button is not disabled
+  this.submit_button().attr("disabled", false);
 
   this.submit_button().bind("click", function(event) {
     event.preventDefault();

test/form_test.js

@@ -58,6 +58,22 @@ jQuery(document).ready(function() {
     same(form.parse_fields(), { foo : { bar : "foobar" }, bar : { zeta : "zetar" } }, "Should parse the input fields correct");
   });
 
+  test("Should correctly initialize semaphore", function() {
+    var semaphore = form._semaphore;
+    ok(typeof semaphore !== "undefined", "Should define semaphore");
+
+    var submit_value = form.submit_button().val();
+    equals(form.submit_button().attr("disabled"), false, "The submit button should not be disabled");
+
+    semaphore.on_unavailable();
+    equals(form.submit_button().attr("disabled"), true, "Should disable the submit button");
+    equals(form.submit_button().val(), "Processing...", "Should change the button inscription");
+
+    semaphore.on_available();
+    equals(form.submit_button().attr("disabled"), false, "Should re-enable the button");
+    equals(form.submit_button().val(), submit_value, "Should restore original button value");
+  });
+
   module("#submit", {
     setup : function() {
       model = {