feat($compile): bind isolate scope properties to controller

It is now possible to ask the $compiler's isolate scope property machinery to bind isolate
scope properties to a controller rather than scope itself. This feature requires the use of
controllerAs, so that the controller-bound properties may still be referenced from binding
expressions in views.

The current syntax is to prefix the scope name with a '@', like so:

    scope: {
        "myData": "=someData",
        "myString": "@someInterpolation",
        "myExpr": "&someExpr"
    },
    controllerAs: "someCtrl",
    bindtoController: true

The putting of properties within the context of the controller will only occur if
controllerAs is used for an isolate scope with the `bindToController` property of the
directive definition object set to `true`.

Closes #7635
Closes #7645

Author: caitp

src/ng/compile.js

@@ -175,6 +175,10 @@
  *   by calling the `localFn` as `localFn({amount: 22})`.
  *
  *
+ * #### `bindToController`
+ * When an isolate scope is used for a component (see above), and `controllerAs` is used, `bindToController` will
+ * allow a component to have its properties bound to the controller, rather than to scope. When the controller
+ * is instantiated, the initial values of the isolate scope bindings are already available.
  *
  * #### `controller`
  * Controller constructor function. The controller is instantiated before the
@@ -981,7 +985,7 @@ function $CompileProvider($provide, $$sanitizeUriProvider) {
 
         if (transcludeControllers) {
           for (var controllerName in transcludeControllers) {
-            $linkNode.data('$' + controllerName + 'Controller', transcludeControllers[controllerName]);
+            $linkNode.data('$' + controllerName + 'Controller', transcludeControllers[controllerName].instance);
           }
         }
 
@@ -1316,6 +1320,7 @@ function $CompileProvider($provide, $$sanitizeUriProvider) {
       var terminalPriority = -Number.MAX_VALUE,
           newScopeDirective,
           controllerDirectives = previousCompileContext.controllerDirectives,
+          controllers,
           newIsolateScopeDirective = previousCompileContext.newIsolateScopeDirective,
           templateDirective = previousCompileContext.templateDirective,
           nonTlbTranscludeDirective = previousCompileContext.nonTlbTranscludeDirective,
@@ -1553,7 +1558,9 @@ function $CompileProvider($provide, $$sanitizeUriProvider) {
           value = null;
 
           if (elementControllers && retrievalMethod === 'data') {
-            value = elementControllers[require];
+            if (value = elementControllers[require]) {
+              value = value.instance;
+            }
           }
           value = value || $element[retrievalMethod]('$' + require + 'Controller');
 
@@ -1586,14 +1593,56 @@ function $CompileProvider($provide, $$sanitizeUriProvider) {
         }
 
         if (newIsolateScopeDirective) {
-          var LOCAL_REGEXP = /^\s*([@=&])(\??)\s*(\w*)\s*$/;
-
           isolateScope = scope.$new(true);
+        }
+
+        transcludeFn = boundTranscludeFn && controllersBoundTransclude;
+        if (controllerDirectives) {
+          // TODO: merge `controllers` and `elementControllers` into single object.
+          controllers = {};
+          elementControllers = {};
+          forEach(controllerDirectives, function(directive) {
+            var locals = {
+              $scope: directive === newIsolateScopeDirective || directive.$$isolateScope ? isolateScope : scope,
+              $element: $element,
+              $attrs: attrs,
+              $transclude: transcludeFn
+            }, controllerInstance;
+
+            controller = directive.controller;
+            if (controller == '@') {
+              controller = attrs[directive.name];
+            }
+
+            controllerInstance = $controller(controller, locals, true, directive.controllerAs);
+
+            // For directives with element transclusion the element is a comment,
+            // but jQuery .data doesn't support attaching data to comment nodes as it's hard to
+            // clean up (http://bugs.jquery.com/ticket/8335).
+            // Instead, we save the controllers for the element in a local hash and attach to .data
+            // later, once we have the actual element.
+            elementControllers[directive.name] = controllerInstance;
+            if (!hasElementTranscludeDirective) {
+              $element.data('$' + directive.name + 'Controller', controllerInstance.instance);
+            }
+
+            controllers[directive.name] = controllerInstance;
+          });
+        }
+
+        if (newIsolateScopeDirective) {
+          var LOCAL_REGEXP = /^\s*([@=&])(\??)\s*(\w*)\s*$/;
 
           compile.$$addScopeInfo($element, isolateScope, true, !(templateDirective && (templateDirective === newIsolateScopeDirective ||
               templateDirective === newIsolateScopeDirective.$$originalDirective)));
           compile.$$addScopeClass($element, true);
 
+          var isolateScopeController = controllers && controllers[newIsolateScopeDirective.name];
+          var isolateBindingContext = isolateScope;
+          if (isolateScopeController && isolateScopeController.identifier &&
+              newIsolateScopeDirective.bindToController === true) {
+            isolateBindingContext = isolateScopeController.instance;
+          }
           forEach(newIsolateScopeDirective.scope, function(definition, scopeName) {
             var match = definition.match(LOCAL_REGEXP) || [],
                 attrName = match[3] || scopeName,
@@ -1614,7 +1663,7 @@ function $CompileProvider($provide, $$sanitizeUriProvider) {
                 if( attrs[attrName] ) {
                   // If the attribute has been provided then we trigger an interpolation to ensure
                   // the value is there for use in the link fn
-                  isolateScope[scopeName] = $interpolate(attrs[attrName])(scope);
+                  isolateBindingContext[scopeName] = $interpolate(attrs[attrName])(scope);
                 }
                 break;
 
@@ -1630,21 +1679,21 @@ function $CompileProvider($provide, $$sanitizeUriProvider) {
                 }
                 parentSet = parentGet.assign || function() {
                   // reset the change, or we will throw this exception on every $digest
-                  lastValue = isolateScope[scopeName] = parentGet(scope);
+                  lastValue = isolateBindingContext[scopeName] = parentGet(scope);
                   throw $compileMinErr('nonassign',
                       "Expression '{0}' used with directive '{1}' is non-assignable!",
                       attrs[attrName], newIsolateScopeDirective.name);
                 };
-                lastValue = isolateScope[scopeName] = parentGet(scope);
+                lastValue = isolateBindingContext[scopeName] = parentGet(scope);
                 var unwatch = scope.$watch($parse(attrs[attrName], function parentValueWatch(parentValue) {
-                  if (!compare(parentValue, isolateScope[scopeName])) {
+                  if (!compare(parentValue, isolateBindingContext[scopeName])) {
                     // we are out of sync and need to copy
                     if (!compare(parentValue, lastValue)) {
                       // parent changed and it has precedence
-                      isolateScope[scopeName] = parentValue;
+                      isolateBindingContext[scopeName] = parentValue;
                     } else {
                       // if the parent can be assigned then do so
-                      parentSet(scope, parentValue = isolateScope[scopeName]);
+                      parentSet(scope, parentValue = isolateBindingContext[scopeName]);
                     }
                   }
                   return lastValue = parentValue;
@@ -1654,7 +1703,7 @@ function $CompileProvider($provide, $$sanitizeUriProvider) {
 
               case '&':
                 parentGet = $parse(attrs[attrName]);
-                isolateScope[scopeName] = function(locals) {
+                isolateBindingContext[scopeName] = function(locals) {
                   return parentGet(scope, locals);
                 };
                 break;
@@ -1667,37 +1716,11 @@ function $CompileProvider($provide, $$sanitizeUriProvider) {
             }
           });
         }
-        transcludeFn = boundTranscludeFn && controllersBoundTransclude;
-        if (controllerDirectives) {
-          elementControllers = {};
-          forEach(controllerDirectives, function(directive) {
-            var locals = {
-              $scope: directive === newIsolateScopeDirective || directive.$$isolateScope ? isolateScope : scope,
-              $element: $element,
-              $attrs: attrs,
-              $transclude: transcludeFn
-            }, controllerInstance;
-
-            controller = directive.controller;
-            if (controller == '@') {
-              controller = attrs[directive.name];
-            }
-
-            controllerInstance = $controller(controller, locals);
-            // For directives with element transclusion the element is a comment,
-            // but jQuery .data doesn't support attaching data to comment nodes as it's hard to
-            // clean up (http://bugs.jquery.com/ticket/8335).
-            // Instead, we save the controllers for the element in a local hash and attach to .data
-            // later, once we have the actual element.
-            elementControllers[directive.name] = controllerInstance;
-            if (!hasElementTranscludeDirective) {
-              $element.data('$' + directive.name + 'Controller', controllerInstance);
-            }
-
-            if (directive.controllerAs) {
-              locals.$scope[directive.controllerAs] = controllerInstance;
-            }
+        if (controllers) {
+          forEach(controllers, function(controller) {
+            controller();
           });
+          controllers = null;
         }
 
         // PRELINKING

src/ng/controller.js

@@ -68,13 +68,24 @@ function $ControllerProvider() {
      * It's just a simple call to {@link auto.$injector $injector}, but extracted into
      * a service, so that one can override this service with [BC version](https://gist.github.com/1649788).
      */
-    return function(expression, locals) {
+    return function(expression, locals, later, ident) {
+      // PRIVATE API:
+      //   param `later` --- indicates that the controller's constructor is invoked at a later time.
+      //                     If true, $controller will allocate the object with the correct
+      //                     prototype chain, but will not invoke the controller until a returned
+      //                     callback is invoked.
+      //   param `ident` --- An optional label which overrides the label parsed from the controller
+      //                     expression, if any.
       var instance, match, constructor, identifier;
+      later = later === true;
+      if (ident && isString(ident)) {
+        identifier = ident;
+      }
 
       if(isString(expression)) {
         match = expression.match(CNTRL_REG),
         constructor = match[1],
-        identifier = match[3];
+        identifier = identifier || match[3];
         expression = controllers.hasOwnProperty(constructor)
             ? controllers[constructor]
             : getter(locals.$scope, constructor, true) ||
@@ -83,19 +94,51 @@ function $ControllerProvider() {
         assertArgFn(expression, constructor, true);
       }
 
-      instance = $injector.instantiate(expression, locals, constructor);
+      if (later) {
+        // Instantiate controller later:
+        // This machinery is used to create an instance of the object before calling the
+        // controller's constructor itself.
+        //
+        // This allows properties to be added to the controller before the constructor is
+        // invoked. Primarily, this is used for isolate scope bindings in $compile.
+        //
+        // This feature is not intended for use by applications, and is thus not documented
+        // publicly.
+        var Constructor = function() {};
+        Constructor.prototype = (isArray(expression) ?
+          expression[expression.length - 1] : expression).prototype;
+        instance = new Constructor();
 
-      if (identifier) {
-        if (!(locals && typeof locals.$scope === 'object')) {
-          throw minErr('$controller')('noscp',
-              "Cannot export controller '{0}' as '{1}'! No $scope object provided via `locals`.",
-              constructor || expression.name, identifier);
+        if (identifier) {
+          addIdentifier(locals, identifier, instance, constructor || expression.name);
         }
 
-        locals.$scope[identifier] = instance;
+        return extend(function() {
+          $injector.invoke(expression, instance, locals, constructor);
+          return instance;
+        }, {
+          instance: instance,
+          identifier: identifier
+        });
+      }
+
+      instance = $injector.instantiate(expression, locals, constructor);
+
+      if (identifier) {
+        addIdentifier(locals, identifier, instance, constructor || expression.name);
       }
 
       return instance;
     };
+
+    function addIdentifier(locals, identifier, instance, name) {
+      if (!(locals && isObject(locals.$scope))) {
+        throw minErr('$controller')('noscp',
+          "Cannot export controller '{0}' as '{1}'! No $scope object provided via `locals`.",
+          name, identifier);
+      }
+
+      locals.$scope[identifier] = instance;
+    }
   }];
 }

test/ng/compileSpec.js

@@ -3516,6 +3516,84 @@ describe('$compile', function() {
       expect(componentScope.$$isolateBindings.exprAlias).toBe('&expr');
 
     }));
+
+
+    it('should expose isolate scope variables on controller with controllerAs when bindToController is true', function() {
+      var controllerCalled = false;
+      module(function($compileProvider) {
+        $compileProvider.directive('fooDir', valueFn({
+          template: '<p>isolate</p>',
+          scope: {
+            'data': '=dirData',
+            'str': '@dirStr',
+            'fn': '&dirFn'
+          },
+          controller: function($scope) {
+            expect(this.data).toEqualData({
+              'foo': 'bar',
+              'baz': 'biz'
+            });
+            expect(this.str).toBe('Hello, world!');
+            expect(this.fn()).toBe('called!');
+            controllerCalled = true;
+          },
+          controllerAs: 'test',
+          bindToController: true
+        }));
+      });
+      inject(function($compile, $rootScope) {
+        $rootScope.fn = valueFn('called!');
+        $rootScope.whom = 'world';
+        $rootScope.remoteData = {
+          'foo': 'bar',
+          'baz': 'biz'
+        };
+        element = $compile('<div foo-dir dir-data="remoteData" ' +
+                                 'dir-str="Hello, {{whom}}!" ' +
+                                 'dir-fn="fn()"></div>')($rootScope);
+        expect(controllerCalled).toBe(true);
+      });
+    });
+
+
+    it('should expose isolate scope variables on controller with controllerAs when bindToController is true', function() {
+      var controllerCalled = false;
+      module(function($compileProvider) {
+        $compileProvider.directive('fooDir', valueFn({
+          templateUrl: 'test.html',
+          scope: {
+            'data': '=dirData',
+            'str': '@dirStr',
+            'fn': '&dirFn'
+          },
+          controller: function($scope) {
+            expect(this.data).toEqualData({
+              'foo': 'bar',
+              'baz': 'biz'
+            });
+            expect(this.str).toBe('Hello, world!');
+            expect(this.fn()).toBe('called!');
+            controllerCalled = true;
+          },
+          controllerAs: 'test',
+          bindToController: true
+        }));
+      });
+      inject(function($compile, $rootScope, $templateCache) {
+        $templateCache.put('test.html', '<p>isolate</p>');
+        $rootScope.fn = valueFn('called!');
+        $rootScope.whom = 'world';
+        $rootScope.remoteData = {
+          'foo': 'bar',
+          'baz': 'biz'
+        };
+        element = $compile('<div foo-dir dir-data="remoteData" ' +
+                                 'dir-str="Hello, {{whom}}!" ' +
+                                 'dir-fn="fn()"></div>')($rootScope);
+        $rootScope.$digest();
+        expect(controllerCalled).toBe(true);
+      });
+    });
   });