feat(ngForm): add ngSubmit support

fire 'submit' event when submit buttons are clicked
in an ngForm (since ngForms don't automatically
fire the 'submit' event)

Closes angular#2513

Author: nelsonpecora

src/ng/directive/form.js

@@ -330,6 +330,14 @@ var formDirectiveFactory = function(isNgForm) {
 
               addEventListenerFn(formElement[0], 'submit', preventDefaultListener);
 
+              if(isNgForm && formElement.children('input[type=submit]')) {
+                if(formElement.children('input[type=submit]')) {
+                  formElement.children('input[type=submit]').on('click', function() {
+                    formElement.trigger('submit');
+                  });
+                }
+              }
+
               // unregister the preventDefault listener so that we don't not leak memory but in a
               // way that will achieve the prevention of the default action.
               formElement.on('$destroy', function() {

test/ng/directive/formSpec.js

@@ -148,6 +148,22 @@ describe('form', function() {
       }).toThrowMinErr('ng', 'badname');
   });
 
+  it('should trigger "submit" event for ngForm when clicking inputs with type="submit"', function() {
+    var callback = jasmine.createSpy('submit').andCallFake(function(event) {
+      expect(event.isDefaultPrevented()).toBe(false);
+      event.preventDefault();
+    });
+
+    doc = $compile('<div ng-form="form">'+
+      '<input name="some" ng-model="some" />'+
+      '<input type="submit" value="Submit" />'+
+      '</div>')(scope);
+    doc.on('submit', callback);
+
+    browserTrigger(doc.find('input[type=submit]'), 'click');
+    expect(callback).toHaveBeenCalledOnce();
+  });
+
 
   describe('preventing default submission', function() {