add support for 404 handling via $route.otherwise

Closes #217

src/services.js

@@ -702,6 +702,22 @@ angularServiceInject('$route', function(location) {
           if (params) extend(route, params);
           dirty++;
           return route;
+        },
+
+        /**
+         * @workInProgress
+         * @ngdoc method
+         * @name angular.service.$route#otherwise
+         * @methodOf angular.service.$route
+         *
+         * @description
+         * Sets route definition that will be used on route change when no other route definition
+         * is matched.
+         *
+         * @param {Object} params Mapping information to be assigned to `$route.current`.
+         */
+        otherwise: function(params) {
+          $route.when(null, params);
         }
       };
   function updateRoute(){
@@ -719,12 +735,26 @@ angularServiceInject('$route', function(location) {
         }
       }
     });
+
+    //fallback
+    if (!childScope && routes[_null]) {
+      childScope = createScope(parentScope);
+      $route.current = extend({}, routes[_null], {
+        scope: childScope,
+        params: extend({}, location.hashSearch)
+      });
+    }
+
+    //fire onChange callbacks
     forEach(onChange, parentScope.$tryEval);
+
     if (childScope) {
       childScope.$become($route.current.controller);
     }
   }
+
   this.$watch(function(){return dirty + location.hash;}, updateRoute);
+
   return $route;
 }, ['$location']);
 

test/servicesSpec.js

@@ -411,6 +411,38 @@ describe("service", function(){
       expect($route.current.controller).toBeUndefined();
       expect(onChangeSpy).toHaveBeenCalled();
     });
+
+    it('should handle unknown routes with "otherwise" route definition', function() {
+      var scope = angular.scope(),
+          $location = scope.$service('$location'),
+          $route = scope.$service('$route'),
+          onChangeSpy = jasmine.createSpy('onChange');
+
+      function NotFoundCtrl() {this.notFoundProp = 'not found!'}
+
+      $route.when('/foo', {template: 'foo.html'});
+      $route.otherwise({template: '404.html', controller: NotFoundCtrl});
+      $route.onChange(onChangeSpy);
+      expect($route.current).toBeNull();
+      expect(onChangeSpy).not.toHaveBeenCalled();
+
+      $location.updateHash('/unknownRoute');
+      scope.$eval();
+
+      expect($route.current.template).toBe('404.html');
+      expect($route.current.controller).toBe(NotFoundCtrl);
+      expect($route.current.scope.notFoundProp).toBe('not found!');
+      expect(onChangeSpy).toHaveBeenCalled();
+
+      onChangeSpy.reset();
+      $location.updateHash('/foo');
+      scope.$eval();
+
+      expect($route.current.template).toEqual('foo.html');
+      expect($route.current.controller).toBeUndefined();
+      expect($route.current.scope.notFoundProp).toBeUndefined();
+      expect(onChangeSpy).toHaveBeenCalled();
+    });
   });