feat(ngModel): add $overrideModelOptions support

This change allows developers to modify the model options for an `ngModel`
directive programmatically.

Author: petebacondarwin

src/ng/directive/ngModel.js

@@ -829,6 +829,29 @@ NgModelController.prototype = {
         that.$commitViewValue();
       });
     }
+  },
+
+  /**
+   * @ngdoc method
+   *
+   * @name ngModel.NgModelController#$overrideModelOptions
+   *
+   * @description
+   *
+   * Override the current model options settings programmatically.
+   *
+   * The previous `ModelOptions` value will not be modified. Instead, the
+   * new `ModelOptions` object will inherit from the previous value of
+   * `NgModelController.$options`.
+   *
+   * See {@link ngModelOptions} for information about what options can be specified
+   * and how model option inheritance works.
+   *
+   * @param {Object} options a hash of settings to override the previous options
+   *
+   */
+  $overrideModelOptions: function(options) {
+    this.$options = this.$options.createChild(options);
   }
 };
 

test/ng/directive/ngModelSpec.js

@@ -1337,6 +1337,35 @@ describe('ngModel', function() {
       });
 
     });
+
+    describe('override ModelOptions', function() {
+      it('should replace the previous model options', function() {
+        var $options = ctrl.$options;
+        ctrl.$overrideModelOptions({});
+        expect(ctrl.$options).not.toBe($options);
+      });
+
+      it('should set the given options', function() {
+        var $options = ctrl.$options;
+        ctrl.$overrideModelOptions({ debounce: 1000, updateOn: 'blur' });
+        expect(ctrl.$options.getOption('debounce')).toEqual(1000);
+        expect(ctrl.$options.getOption('updateOn')).toEqual('blur');
+        expect(ctrl.$options.getOption('updateOnDefault')).toBe(false);
+      });
+
+      it('should inherit from a parent model options', inject(function($compile, $rootScope) {
+        var element = $compile(
+          '<form name="form" ng-model-options="{debounce: 1000, updateOn: \'blur\'}">' +
+           '<input ng-model="value" name="input">' +
+          '</form>')($rootScope);
+        var ctrl = $rootScope.form.input;
+        ctrl.$overrideModelOptions({ debounce: 2000, '*': '$inherit' });
+        expect(ctrl.$options.getOption('debounce')).toEqual(2000);
+        expect(ctrl.$options.getOption('updateOn')).toEqual('blur');
+        expect(ctrl.$options.getOption('updateOnDefault')).toBe(false);
+        dealoc(element);
+      }));
+    });
   });