feat(directive): support as instance syntax

Support controller: 'MyController as my' syntax for directives which publishes
the controller instance to the directive scope.

Support controllerAs syntax to define an alias to the controller within the
directive scope.

Author: lgalfaso

docs/content/guide/directive.ngdoc

@@ -401,6 +401,13 @@ compiler}. The attributes are:
     * `^` - Locate the required controller by searching the element's parents.
     * `?^` - Attempt to locate the required controller by searching the element's parents, or return `null` if not found.
 
+  * `controllerAs` - Controller alias at the directive scope. An alias for the controller so it
+    can be referenced at the directive template. The directive needs to define a scope for this
+    configuration to be used. Useful in the case when directive is used as component.
+  
+  * `require` - Require another controller be passed into current directive linking function. The
+    `require` takes a name of the directive controller to pass in. If no such controller can be
+    found an error is raised. The name can be prefixed with:
 
   * `restrict` - String of subset of `EACM` which restricts the directive to a specific directive
     declaration style. If omitted, the default (attributes only) is used.

src/ng/compile.js

@@ -961,16 +961,25 @@ function $CompileProvider($provide) {
               $element: $element,
               $attrs: attrs,
               $transclude: boundTranscludeFn
-            };
+            }, controllerInstance;
 
             controller = directive.controller;
             if (controller == '@') {
               controller = attrs[directive.name];
             }
 
+            controllerInstance = $controller(controller, locals);
             $element.data(
                 '$' + directive.name + 'Controller',
-                $controller(controller, locals));
+                controllerInstance);
+            if (directive.controllerAs) {
+              if (typeof locals.$scope !== 'object') {
+                throw new Error('Can not export controller as "' + identifier + '". ' +
+                    'No scope object provided!');
+              }
+
+              locals.$scope[directive.controllerAs] = controllerInstance;
+            }
           });
         }
 

test/ng/compileSpec.js

@@ -2244,6 +2244,52 @@ describe('$compile', function() {
     });
 
 
+    iit('should support controllerAs', function() {
+      module(function() {
+        directive('main', function() {
+          return {
+            templateUrl: 'main.html',
+            transclude: true,
+            scope: {},
+            controller: function() {
+              this.name = 'lucas';
+            },
+            controllerAs: 'mainCtrl'
+          };
+        });
+      });
+      inject(function($templateCache, $compile, $rootScope) {
+        $templateCache.put('main.html', '<span>template:{{mainCtrl.name}} <div ng-transclude></div></span>');
+        element = $compile('<div main>transclude:{{mainCtrl.name}}</div>')($rootScope);
+        $rootScope.$apply();
+        expect(element.text()).toBe('template:lucas transclude:');
+      });
+    });
+
+
+    it('should support controller alias', function() {
+      module(function($controllerProvider) {
+        $controllerProvider.register('MainCtrl', function() {
+          this.name = 'lucas';
+        });
+        directive('main', function() {
+          return {
+            templateUrl: 'main.html',
+            scope: {},
+            controller: 'MainCtrl as mainCtrl'
+          };
+        });
+      });
+      inject(function($templateCache, $compile, $rootScope) {
+        $templateCache.put('main.html', '<span>{{mainCtrl.name}}</span>');
+        element = $compile('<div main></div>')($rootScope);
+        $rootScope.$apply();
+        expect(element.text()).toBe('lucas');
+      });
+    });
+
+
+
     it('should require controller on parent element',function() {
       module(function() {
         directive('main', function(log) {