Develop Reference

AngularJS rootScope.$emit from within Directive

I have a directive for users to like (or "fave") posts in my application. Throughout my controllers I use $rootScope.$emit('name-of-function', some-id) to update user data when they like a new post, as this is reflected throughout my application. But I can't seem to use $rootScope.$emit in the directive. I receive an error
$rootScope.$emit is not a function
Presumably the $rootScope.$on event which corresponds with this command has not been called yet, so this function does not yet exist? What can be done about this? Is there a better way to arrange this?
var module = angular.module('directives.module');
module.directive('postFave', function (contentService, $rootScope) {
return {
restrict: 'E',
templateUrl: 'directives/post-fave.html',
scope: {
contentId: '#',
slug: '#'
},
link: function ($scope, $rootScope, element) {
$scope.contentFavToggle = function (ev) {
contentId = $scope.contentId;
contentService.contentFavToggle(contentId, ev).then(function (response) {
$rootScope.$emit('dataUpdated', $scope.slug);
if (response) {
$scope.favourite[contentId] = response;
} else {
$scope.favourite[contentId] = null;
}
});
};
console.log("track fave directive called");
}
};
});
from controller:
var dataUpdatedListener = $rootScope.$on('dataUpdated', function (event, slug) {
dataService.clearData(slug);
dataControllerInit();
});
How can I access this rootscope function from within the directive? Thanks.
FYI - "link" has been used in the directive because this is related to an instance of an HTML element which will be used a number of times on the page

link has the following signature, there is no need to add $rootScope injection into link function:
function link(scope, element, attrs, controller, transcludeFn) { ... }
Remove it from link and it will work.

Binding a Directive Controller's method to its parent $scope

I will explain what exactly I'm trying to do before explaining the issue. I have a Directive which holds a form, and I need to access that form from the parent element (where the Directive is used) when clicking on a submit button to check fi the form is valid.
To do this, I am trying to use $scope.$parent[$attrs.directiveName] = this; and then binding some methods to the the Directive such as this.isValid which will be exposed and executable in the parent.
This works fine when running locally, but when minifying and building my code (Yeoman angular-fullstack) I will get an error for aProvider being unknown which I traced back to a $scopeProvider error in the Controller.
I've had similar issues in the past, and my first thought was that I need to specifically say $inject for $scope so that the name isn't lost. But alas.....no luck.
Is something glaringly obvious that I am doing wrong?
Any help appreciated.
(function() {
'use strict';
angular
.module('myApp')
.directive('formDirective', formDirective);
function formDirective() {
var directive = {
templateUrl: 'path/to/template.html',
restrict: 'EA',
scope: {
user: '='
},
controller: controller
};
return directive;
controller.$inject = ['$scope', '$attrs', 'myService'];
function controller($scope, $attrs, myService) {
$scope.myService = myService;
// Exposes the Directive Controller on the parent Scope with name Directive's name
$scope.$parent[$attrs.directiveName] = this;
this.isValid = function() {
return $scope.myForm.$valid;
};
this.setDirty = function() {
Object.keys($scope.myForm).forEach(function(key) {
if (!key.match(/\$/)) {
$scope.myForm[key].$setDirty();
$scope.myForm[key].$setTouched();
}
});
$scope.myForm.$setDirty();
};
}
}
})();

Change the directive to a component and implement a clear interface.
Parent Container (parent.html):
<form-component some-input="importantInfo" on-update="someFunction(data)">
</form-component>
Parent controller (parent.js):
//...
$scope.importantInfo = {data: 'data...'};
$scope.someFunction = function (data) {
//do stuff with the data
}
//..
form-component.js:
angular.module('app')
.component('formComponent', {
template:'<template-etc>',
controller: Controller,
controllerAs: 'ctrl',
bindings: {
onUpdate: '&',
someInput: '<'
}
});
function Controller() {
var ctrl = this;
ctrl.someFormThing = function (value) {
ctrl.onUpdate({data: value})
}
}
So if an event in your form triggers the function ctrl.someFormThing(data). This can be passed up to the parent by calling ctrl.onUpdate().

Dynamic controller for directives with ECMA6

I'm trying to set a controller dynamically to my directive using the name property. So far this is my code.
html
<view-edit controller-name="vm.controller" view="home/views/med.search.results.detail.resources.audios.html" edit="home/views/med.media.resources.edit.html"></view-edit>
js
export default class SearchResultsCtrl extends Pageable {
/*#ngInject*/
constructor($injector, $state, api) {
super(
{
injector: $injector,
endpoint: 'mediaMaterialsList',
selectable:{
itemKey: 'cid',
enabled:true,
params: $state.params
},
executeGet: false
}
);
this.controller = SearchResultsResourcesAudiosCtrl;
}
}
Directive
export default class ViewEditDirective {
constructor() {
this.restrict = 'E';
this.replace = true;
this.templateUrl = 'home/views/med.view.edit.html';
this.scope = {};
this.controller = "#";
this.name = "controllerName";
this.bindToController = {
'view': '#?',
'edit': '#?'
};
this.open = false;
this.controllerAs = 'ctrl';
}
}
I get undefined for vm.controller. I guess that it's rendering before the controller can assign the controller to the variable (I debbuged it, and it's setting the controller in the variable).
I'm following this answer to achieve this, but no luck so far.
How to set the dynamic controller for directives?
Thanks.

The problem is not related to ES6 (which is a sugar syntax coating over ES5), this is how Angular scope life cycle works.
This directive may show what's the deal with attribute interpolation
// <div ng-init="a = 1"><div sum="{{ a + 1 }}"></div></div>
app.directive('sum', function () {
return {
scope: {},
controller: function ($attrs) {
console.log($attrs.sum) // {{ a + 1 }}
// ...
},
link: function (scope, element, attrs) {
console.log(attrs.sum) // 2
}
};
});
And $attrs.sum may still not be 2 in link if a value was set after that (i.e. in parent directive link).
It is unsafe (and wrong per se) to assume that the value on one scope can be calculated based on the value from another scopes at some point of time. Because it may be not. That is why watchers and data binding are there.
All that controller: '#' magic value does is getting uninterpolated attribute value and using it as controller name. So no, it won't interpolate controller name from vm.controller and will use 'vm.controller' string as controller name.
An example of a directive that allows to set its controller dynamically may look like
// dynamic-controller="{{ ctrlNameVariable }}"
app.directive('dynamicController', function () {
return {
restrict: 'A',
priority: 2500,
controller: function ($scope, $element, $attrs, $interpolate, $compile) {
var ctrlName = $interpolate($attrs.dynamicController)($scope);
setController(ctrlName);
$attrs.$observe('dynamicController', setController);
function setController (ctrlName) {
if (!ctrlName || $attrs.ngController === ctrlName) {
return;
}
$attrs.$set('ngController', ctrlName);
$compile($element)($scope);
}
}
};
});
with all the side-effects that re-compilation may bring.

How to access a require'd controller from another controller?

I have an Angular 1.3 module that looks something like this (directive that requires the presence of a parent directive, using controllerAs):
angular.module('fooModule', [])
.controller('FooController', function ($scope) {
this.doSomething = function () {
// Accessing parentDirectiveCtrl via $scope
$scope.parentDirectiveCtrl();
};
})
.directive('fooDirective', function () {
return {
// Passing in parentDirectiveCtrl into $scope here
link: function link(scope, element, attrs, parentDirectiveCtrl) {
scope.parentDirectiveCtrl = parentDirectiveCtrl;
},
controller: 'FooController',
controllerAs: 'controller',
bindToController: true,
require: '^parentDirective'
};
});
Here I'm just using $scope to pass through parentDirectiveCtrl, which seems a little clunky.
Is there another way to access the require-ed controller from the directive's controller without the linking function?

You must use the link function to acquire the require-ed controllers, but you don't need to use the scope to pass the reference of the controller to your own. Instead, pass it directly to your own controller:
.directive('fooDirective', function () {
return {
require: ["fooDirective", "^parentDirective"],
link: function link(scope, element, attrs, ctrls) {
var me = ctrls[0],
parent = ctrls[1];
me.parent = parent;
},
controller: function(){...},
};
});
Be careful, though, since the controller runs prior to link, so within the controller this.parent is undefined, until after the link function runs. If you need to know exactly when that happens, you can always use a controller function to pass the parentDirective controller to:
link: function link(scope, element, attrs, ctrls) {
//...
me.registerParent(parent);
},
controller: function(){
this.registerParent = function(parent){
//...
}
}

There is a way to avoid using $scope to access parent controller, but you have to use link function.
Angular's documentation says:
Require
Require another directive and inject its controller as the fourth
argument to the linking function...
Option 1
Since controllerAs creates namespace in scope of your controller, you can access this namespace inside your link function and put required controller directly on controller of childDirective instead of using $scope. Then the code will look like this.
angular.module('app', []).
controller('parentController', function() {
this.doSomething = function() {
alert('parent');
};
}).
controller('childController', function() {
this.click = function() {
this.parentDirectiveCtrl.doSomething();
}
}).
directive('parentDirective', function() {
return {
controller: 'parentController'
}
}).
directive('childDirective', function() {
return {
template: '<button ng-click="controller.click()">Click me</button>',
link: function link(scope, element, attrs, parentDirectiveCtrl) {
scope.controller.parentDirectiveCtrl = parentDirectiveCtrl;
},
controller: 'childController',
controllerAs: 'controller',
bindToController: true,
require: '^parentDirective'
}
});
Plunker:
http://plnkr.co/edit/YwakJATaeuvUV2RBDTGr?p=preview
Option 2
I usually don't use controllers in my directives at all and share functionality via services. If you don't need to mess with isolated scopes of parent and child directives, simply inject the same service to both of them and put all functionality to service.
angular.module('app', []).
service('srv', function() {
this.value = '';
this.doSomething = function(source) {
this.value = source;
}
}).
directive('parentDirective', ['srv', function(srv) {
return {
template: '<div>' +
'<span ng-click="srv.doSomething(\'parent\')">Parent {{srv.value}}</span>' +
'<span ng-transclude></span>' +
'</div>',
transclude: true,
link: function(scope) { scope.srv = srv; }
};
}]).
directive('childDirective', ['srv', function(srv) {
return {
template: '<button ng-click="srv.doSomething(\'child\')">Click me</button>',
link: function link(scope) { scope.srv = srv; }
}
}]);
Plunker
http://plnkr.co/edit/R4zrXz2DBzyOuhugRU5U?p=preview

Good question! Angular lets you pass "parent" controller. You already have it as a parameter on your link function. It is the fourth parameter. I named it ctrl for simplicity. You do not need the scope.parentDirectiveCtrl=parentDirectiveCtrl line that you have.
.directive('fooDirective', function () {
return {
// Passing in parentDirectiveCtrl into $scope here
link: function link(scope, element, attrs, ctrl) {
// What you had here is not required.
},
controller: 'FooController',
controllerAs: 'controller',
bindToController: true,
require: '^parentDirective'};});
Now on your parent controller you have
this.doSomething=function().
You can access this doSomething as
ctrl.doSomething().

What's the recommended way to extend AngularJS controllers?

I have three controllers that are quite similar. I want to have a controller which these three extend and share its functions.

Perhaps you don't extend a controller but it is possible to extend a controller or make a single controller a mixin of multiple controllers.
module.controller('CtrlImplAdvanced', ['$scope', '$controller', function ($scope, $controller) {
// Initialize the super class and extend it.
angular.extend(this, $controller('CtrlImpl', {$scope: $scope}));
… Additional extensions to create a mixin.
}]);
When the parent controller is created the logic contained within it is also executed.
See $controller() for for more information about but only the $scope value needs to be passed. All other values will be injected normally.
#mwarren, your concern is taken care of auto-magically by Angular dependency injection. All you need is to inject $scope, although you could override the other injected values if desired.
Take the following example:
(function(angular) {
var module = angular.module('stackoverflow.example',[]);
module.controller('simpleController', function($scope, $document) {
this.getOrigin = function() {
return $document[0].location.origin;
};
});
module.controller('complexController', function($scope, $controller) {
angular.extend(this, $controller('simpleController', {$scope: $scope}));
});
})(angular);
<script src="https://cdnjs.cloudflare.com/ajax/libs/angular.js/1.3.15/angular.js"></script>
<div ng-app="stackoverflow.example">
<div ng-controller="complexController as C">
<span><b>Origin from Controller:</b> {{C.getOrigin()}}</span>
</div>
</div>
Although $document is not passed into 'simpleController' when it is created by 'complexController' $document is injected for us.

For inheritance you can use standard JavaScript inheritance patterns.
Here is a demo which uses $injector
function Parent($scope) {
$scope.name = 'Human';
$scope.clickParent = function() {
$scope.name = 'Clicked from base controller';
}
}
function Child($scope, $injector) {
$injector.invoke(Parent, this, {$scope: $scope});
$scope.name = 'Human Child';
$scope.clickChild = function(){
$scope.clickParent();
}
}
Child.prototype = Object.create(Parent.prototype);
In case you use the controllerAs syntax (which I highly recommend), it is even easier to use the classical inheritance pattern:
function BaseCtrl() {
this.name = 'foobar';
}
BaseCtrl.prototype.parentMethod = function () {
//body
};
function ChildCtrl() {
BaseCtrl.call(this);
this.name = 'baz';
}
ChildCtrl.prototype = Object.create(BaseCtrl.prototype);
ChildCtrl.prototype.childMethod = function () {
this.parentMethod();
//body
};
app.controller('BaseCtrl', BaseCtrl);
app.controller('ChildCtrl', ChildCtrl);
Another way could be to create just "abstract" constructor function which will be your base controller:
function BaseController() {
this.click = function () {
//some actions here
};
}
module.controller('ChildCtrl', ['$scope', function ($scope) {
BaseController.call($scope);
$scope.anotherClick = function () {
//other actions
};
}]);
Blog post on this topic

Well, I'm not exactly sure what you want to achieve, but usually Services are the way to go.
You can also use the Scope inheritance characteristics of Angular to share code between controllers:
<body ng-controller="ParentCtrl">
<div ng-controller="FirstChildCtrl"></div>
<div ng-controller="SecondChildCtrl"></div>
</body>
function ParentCtrl($scope) {
$scope.fx = function() {
alert("Hello World");
});
}
function FirstChildCtrl($scope) {
// $scope.fx() is available here
}
function SecondChildCtrl($scope) {
// $scope.fx() is available here
}

You don't extend controllers. If they perform the same basic functions then those functions need to be moved to a service. That service can be injected into your controllers.

Yet another good solution taken from this article:
// base controller containing common functions for add/edit controllers
module.controller('Diary.BaseAddEditController', function ($scope, SomeService) {
$scope.diaryEntry = {};
$scope.saveDiaryEntry = function () {
SomeService.SaveDiaryEntry($scope.diaryEntry);
};
// add any other shared functionality here.
}])
module.controller('Diary.AddDiaryController', function ($scope, $controller) {
// instantiate base controller
$controller('Diary.BaseAddEditController', { $scope: $scope });
}])
module.controller('Diary.EditDiaryController', function ($scope, $routeParams, DiaryService, $controller) {
// instantiate base controller
$controller('Diary.BaseAddEditController', { $scope: $scope });
DiaryService.GetDiaryEntry($routeParams.id).success(function (data) {
$scope.diaryEntry = data;
});
}]);

You can create a service and inherit its behaviour in any controller just by injecting it.
app.service("reusableCode", function() {
var reusableCode = {};
reusableCode.commonMethod = function() {
alert('Hello, World!');
};
return reusableCode;
});
Then in your controller that you want to extend from the above reusableCode service:
app.controller('MainCtrl', function($scope, reusableCode) {
angular.extend($scope, reusableCode);
// now you can access all the properties of reusableCode in this $scope
$scope.commonMethod()
});
DEMO PLUNKER: http://plnkr.co/edit/EQtj6I0X08xprE8D0n5b?p=preview

You can try something like this (have not tested):
function baseController(callback){
return function($scope){
$scope.baseMethod = function(){
console.log('base method');
}
callback.apply(this, arguments);
}
}
app.controller('childController', baseController(function(){
}));

You can extend with a services, factories or providers. they are the same but with different degree of flexibility.
here an example using factory : http://jsfiddle.net/aaaflyvw/6KVtj/2/
angular.module('myApp',[])
.factory('myFactory', function() {
var myFactory = {
save: function () {
// saving ...
},
store: function () {
// storing ...
}
};
return myFactory;
})
.controller('myController', function($scope, myFactory) {
$scope.myFactory = myFactory;
myFactory.save(); // here you can use the save function
});
And here you can use the store function also:
<div ng-controller="myController">
<input ng-blur="myFactory.store()" />
</div>

You can directly use $controller('ParentController', {$scope:$scope})
Example
module.controller('Parent', ['$scope', function ($scope) {
//code
}])
module.controller('CtrlImplAdvanced', ['$scope', '$controller', function ($scope, $controller) {
//extend parent controller
$controller('CtrlImpl', {$scope: $scope});
}]);

You can use Angular "as" syntax combined with plain JavaScript inheritance
See more details here
http://blogs.microsoft.co.il/oric/2015/01/01/base-controller-angularjs/

I wrote a function to do this:
function extendController(baseController, extension) {
return [
'$scope', '$injector',
function($scope, $injector) {
$injector.invoke(baseController, this, { $scope: $scope });
$injector.invoke(extension, this, { $scope: $scope });
}
]
}
You can use it like this:
function() {
var BaseController = [
'$scope', '$http', // etc.
function($scope, $http, // etc.
$scope.myFunction = function() {
//
}
// etc.
}
];
app.controller('myController',
extendController(BaseController,
['$scope', '$filter', // etc.
function($scope, $filter /* etc. */)
$scope.myOtherFunction = function() {
//
}
// etc.
}]
)
);
}();
Pros:
You don't have to register the base controller.
None of the controllers need to know about the $controller or $injector services.
It works well with angular's array injection syntax - which is essential if your javascript is going to be minified.
You can easily add extra injectable services to the base controller, without also having to remember to add them to, and pass them through from, all of your child controllers.
Cons:
The base controller has to be defined as a variable, which risks polluting the global scope. I've avoided this in my usage example by wrapping everything in an anonymous self-executing function, but this does mean that all of the child controllers have to be declared in the same file.
This pattern works well for controllers which are instantiated directly from your html, but isn't so good for controllers that you create from your code via the $controller() service, because it's dependence on the injector prevents you from directly injecting extra, non-service parameters from your calling code.

I consider extending controllers as bad-practice. Rather put your shared logic into a service. Extended objects in javascript tend to get rather complex. If you want to use inheritance, I would recommend typescript. Still, thin controllers are better way to go in my point of view.