What's the recommended way to extend AngularJS controllers? - javascript

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.

Related

How to create / instantiate AngularJs controllers on the fly?

I have a simple controller that works just fine:
app.controller('IndexController', ['$scope', obj.indexPage]);
var obj = {};
obj.indexPage = function ($scope) { // do controller stuff };
I also have an event function that i want to use to load/create/instantiate this controller:
// some callback, doesn't really matter
app.onPage('index', function () {
// load and run controller logic in here
app.controller('IndexController', ['$scope', obj.indexPage]);
}, obj);
there are some issues, like Argument 'IndexController' is not a function, got undefined
Any ideas?
my solution:
app.controller('IndexController', ['$scope', function ($scope) {
var obj = {};
obj.indexPage = function (data) {
// do controller stuff
};
app.onPage('index', function (data) {
obj.indexPage(data);
}, obj);
});

Due to how the angular module system works, you can't instantiate controllers asynchronously like that. You can however, use the $controller service to create controllers on the fly. The same technique below is often used in unit testing.
For example:
angular.module('app', [])
.controller('MyCtrl', function($rootScope, CtrlFactory){
var dynamicCtrl = CtrlFactory.create({$scope: $rootScope.$new()});
console.log(dynamicCtrl.method()); //-> 123
})
.factory('CtrlFactory', function($controller) {
return {
create: function(locals) {
return $controller(
//this is the constructor of the new controller
function($scope){
console.log('Dynamic controller', $scope);
this.method = function() { return 123; };
},
//these are the injected deps
locals
);
}
};
})
For some example usage in a unit testing context, see: https://docs.angularjs.org/guide/controller.
I'll add that you may want to reconsider your reasons for doing this--I can't say I've seen $controller used outside testing.

app.onPage('index', function () {
app.controller('IndexController', obj.indexPage); // this would load the controller to the module
$controller('IndexController', { $scope: $scope }); // This would instantiate the controller, NOTE: $controller service should be injected
}, obj);

Getting injected service from controller prototype

I'm trying to optimize my code by using prototype inheritance in a controller used by a directive. Since directives can be invoked several times, I thought it might be a good idea to do this. But my controllers prototype is depending on injected services, which angular complains it does not have access to.
(function (angular) {
'use strict';
angular.module('myModule', [])
.factory('MyService', MyService)
.controller('myController', MyController);
// My service
function MyService() {
return {
getMyStuff: getMyStuff
}
function getMyStuff() {
return 'stuff';
}
}
// My controller
MyController.$inject = ['MyService'];
function MyController(MyService) {
var ctrl = this;
// Provide some value to the template
}
MyController.prototype = {
getStuff: function () {
return MyService.getMyStuff(); // This does not work. MyService is not available from the prototype. Why??
}
}
})(angular);
How can I make the MyService available to the prototype?
I've even tried to use the $injector service in order to get it, but
getStuff: function () {
return angular.injector(['myModule']).get('MyService').getMyStuff();
}
complains even more...

Angularjs ng-controller with resolve

I've ran into problem with ng-controller and 'resolve' functionality:
I have a controller that requires some dependency to be resolved before running, it works fine when I define it via ng-route:
Controller code looks like this:
angular.module('myApp')
.controller('MyController', ['$scope', 'data', function ($scope, data) {
$scope.data = data;
}
]
);
Routing:
...
.when('/someUrl', {
templateUrl : 'some.html',
controller : 'MyController',
resolve : {
data: ['Service', function (Service) {
return Service.getData();
}]
}
})
...
when I go to /someUrl, everything works.
But I need to use this controller in other way(I need both ways in different places):
<div ng-controller="MyController">*some html here*</div>
And, of course, it fails, because 'data' dependency wasn't resolved. Is there any way to inject dependency into controller when I use 'ng-controller' or I should give up and load data inside controller?

In the below, for the route resolve, we're resolving the promise and wrapping the return data in an object with a property. We then duplicate this structure in the wrapper service ('dataService') that we use for the ng-controller form.
The wrapper service also resolves the promise but does so internally, and updates a property on the object we've already returned to be consumed by the controller.
In the controller, you could probably put a watcher on this property if you wanted to delay some additional behaviours until after everything was resolved and the data was available.
Alternatively, I've demonstrated using a controller that 'wraps' another controller; once the promise from Service is resolved, it then passes its own $scope on to the wrapped controller as well as the now-resolved data from Service.
Note that I've used $timeout to provide a 1000ms delay on the promise return, to try and make it a little more clear what's happening and when.
angular.module('myApp', ['ngRoute'])
.config(function($routeProvider) {
$routeProvider
.when('/', {
template: '<h1>{{title}}</h1><p>{{blurb}}</p><div ng-controller="ResolveController">Using ng-controller: <strong>{{data.data}}</strong></div>',
controller: 'HomeController'
})
.when('/byResolve', {
template: '<h1>{{title}}</h1><p>{{blurb}}</p><p>Resolved: <strong>{{data.data}}</strong></p>',
controller: "ResolveController",
resolve: {
dataService: ['Service',
function(Service) {
// Here getData() returns a promise, so we can use .then.
// I'm wrapping the result in an object with property 'data', so we're returning an object
// which can be referenced, rather than a string which would only be by value.
// This mirrors what we return from dataService (which wraps Service), making it interchangeable.
return Service.getData().then(function(result) {
return {
data: result
};
});
}
]
}
})
.when('/byWrapperController', {
template: '<h1>Wrapped: {{title}}</h1><p>{{blurb}}</p><div ng-controller="WrapperController">Resolving and passing to a wrapper controller: <strong>{{data.data ? data.data : "Loading..."}}</strong></div>',
controller: 'WrapperController'
});
})
.controller('HomeController', function($scope) {
$scope.title = "ng-controller";
$scope.blurb = "Click 'By Resolve' above to trigger the next route and resolve.";
})
.controller('ResolveController', ['$scope', 'dataService',
function($scope, dataService) {
$scope.title = "Router and resolve";
$scope.blurb = "Click 'By ng-controller' above to trigger the original route and test ng-controller and the wrapper service, 'dataService'.";
$scope.data = dataService;
}
])
.controller('WrapperController', ['$scope', '$controller', 'Service',
function($scope, $controller, Service) {
$scope.title = "Resolving..."; //this controller could of course not show anything until after the resolve, but demo purposes...
Service.getData().then(function(result) {
$controller('ResolveController', {
$scope: $scope, //passing the same scope on through
dataService: {
data: result
}
});
});
}
])
.service('Service', ['$timeout',
function($timeout) {
return {
getData: function() {
//return a test promise
return $timeout(function() {
return "Data from Service!";
}, 1000);
}
};
}
])
// our wrapper service, that will resolve the promise internally and update a property on an object we can return (by reference)
.service('dataService', function(Service) {
// creating a return object with a data property, matching the structure we return from the router resolve
var _result = {
data: null
};
Service.getData().then(function(result) {
_result.data = result;
return result;
});
return _result;
});
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.27/angular.min.js"></script>
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.27/angular-route.min.js"></script>
<div ng-app="myApp">
By ng-controller |
By Resolve |
By Wrapper Controller
<div ng-view />
</div>

Create a new module inside which you have the service to inject like seen below.
var module = angular.module('myservice', []);
module.service('userService', function(Service){
return Service.getData();
});
Inject newly created service module inside your app module
angular.module('myApp')
.controller('MyController', ['$scope', 'myservice', function ($scope, myservice) {
$scope.data = data;
// now you can use new dependent service anywhere here.
}
]
);

You can use the mechanism of the prototype.
.when('/someUrl', {
template : '<div ng-controller="MyController" ng-template="some.html"></div>',
controller: function (data) {
var pr = this;
pr.data = data;
},
controllerAs: 'pr',
resolve : {
data: ['Service', function (Service) {
return Service.getData();
}]
}
})
angular.module('myApp')
.controller('MyController', ['$scope', function ($scope) {
$scope.data = $scope.pr.data; //magic
}
]
);
Now wherever you want to use
'<div ng-controller="MyController"></div>'
you need to ensure that there pr.data in the Scope of the calling controller. As an example uib-modal
var modalInstance = $modal.open({
animation: true,
templateUrl: 'modal.html',
resolve: {
data: ['Service', function (Service) {
return Service.getData();
}]
},
controller: function ($scope, $modalInstance, data) {
var pr = this;
pr.data = data;
pr.ok = function () {
$modalInstance.close();
};
},
controllerAs:'pr',
size:'sm'
});
modal.html
<script type="text/ng-template" id="modal.html">
<div class="modal-body">
<div ng-include="some.html" ng-controller="MyController"></div>
</div>
<div class="modal-footer">
<button class="btn btn-primary pull-right" type="button" ng-click="pr.ok()">{{ 'ok' | capitalize:'first'}}</button>
</div>
</script>
And now you can use $scope.data = $scope.pr.data; in MyController
pr.data is my style. You can rewrite the code without PR.
the basic principle of working with ng-controller described in this video https://egghead.io/lessons/angularjs-the-dot

Presuming that Service.getData() returns a promise, MyController can inject that Service as well. The issue is that you want to delay running the controller until the promise resolves. While the router does this for you, using the controller directly means that you have to build that logic.
angular.module('myApp')
.controller('MyController', ['$scope', 'Service', function ($scope, Service) {
$scope.data = {}; // default values for data
Service.getData().then(function(data){
// data is now resolved... do stuff with it
$scope.data = data;
});
}]
);
Now this works great when using the controller directly, but in your routing example, where you want to delay rendering a page until data is resolved, you are going to end up making two calls to Service.getData(). There are a few ways to work around this issue, like having Service.getData() return the same promise for all caller, or something like this might work to avoid the second call entirely:
angular.module('myApp')
.controller('MyController', ['$scope', '$q', 'Service', function ($scope, $q, Service) {
var dataPromise,
// data might be provided from router as an optional, forth param
maybeData = arguments[3]; // have not tried this before
$scope.data = {}; //default values
// if maybeData is available, convert it to a promise, if not,
// get a promise for fetching the data
dataPromise = !!maybeData?$q.when(maybeData):Service.getData();
dataPromise.then(function(data){
// data is now resolved... do stuff with it
$scope.data = data;
});
}]
);

I was trying to solve the problem using ng-init but came across the following warnings on angularjs.org
The only appropriate use of ngInit is for aliasing special properties
of ngRepeat, as seen in the demo below. Besides this case, you should
use controllers rather than ngInit to initialize values on a scope.
So I started searching for something like ng-resolve and came across the following thread:
https://github.com/angular/angular.js/issues/2092
The above link consists of a demo fiddle that have ng-resolve like functionality. I think ng-resolve can become a feature in the future versions of angular 1.x. For now we can work around with the directive mentioned in the above link.

'data' from route resolve will not be available for injection to a controller activated other than route provider. it will be available only to the view configured in the route provider.
if you want the data to the controller activated directly other than routeprovider activation, you need to put a hack for it.
see if this link helps for it:
http://www.johnpapa.net/route-resolve-and-controller-activate-in-angularjs/

Getting data in "resolve" attribute is the functionality of route (routeProvider) , not the functionality of controller.
Key( is your case : 'data') in resolve attribute is injected as service.
That's why we are able fetch data from that service.
But to use same controller in different place , you have fetch data in controller.

Try this
Service:
(function() {
var myService = function($http) {
var getData = function() {
//return your result
};
return {
getData:getData
};
};
var myApp = angular.module("myApp");
myApp.factory("myService", myService);
}());
Controller:
(function () {
var myApp = angular.module("myApp");
myApp.controller('MyController', [
'$scope', 'myService', function($scope, myService) {
$scope.data = myService.getData();
}
]);
//Routing
.when('/someUrl', {
templateUrl : 'some.html',
controller : 'MyController',
resolve : {
data: $scope.data,
}
})
}());

Unit testing angular/Ionic project

I have a very simple controller that looks like this.
timeInOut.controller('timeInOutController', function($scope, $filter, $ionicScrollDelegate){
...
});
Whenever I try to create a unit test for it like so...
(function() {
'use strict';
var scope, controller, filter;
describe('timeInOutController', function () {
beforeEach(module('common.directives.kmDateToday'));
beforeEach(inject(function ($rootScope, $controller, $filter) {
scope = $rootScope.$new();
filter = $filter;
controller = $controller('timeInOutController', {
$scope: scope
});
}));
describe('#date setting', function(){
...
});
});
})();
I get the error:
[$injector:unpr] Unknown provider: $ionicScrollDelegateProvider <- $ionicScrollDelegate
Obviously in my example here I'm not trying to inject the $ionicScrollDelegate into the test, that's just because I've tried it any number of ways with no success and don't know which failed attempt to include.
Also in my karma.conf.js file I am including the ionic.bundle.js and angular-mocks.js libraries/files.
I can successfully unit test anything that doesn't use anything $ionic in it, so I know my testing framework is set up correctly, the issue is injecting anything ionic related.

You need to pass in all the parameters if you're going to instantiate your controller via angular. By adding the parameters you are telling angular that any time you create one of these controllers I need these things too because I am dependent upon them.
So my suggestion is to mock up some representation of these dependencies and inject them in when you are creating the controller. They do not have to be (and should not be) the actual services for your unit tests. Jasmine gives you the ability to create spy objects that you can inject so you can verify the the behavior of this unit.
(function() {
'use strict';
var scope, controller, filter, ionicScrollDelegate;
describe('timeInOutController', function () {
beforeEach(module('common.directives.kmDateToday'));
beforeEach(inject(function ($rootScope, $controller, $filter) {
scope = $rootScope.$new();
filter = $filter;
// func1 and func2 are functions that will be created as spies on ionicScrollDelegate
ionicScrollDelegate = jasmine.createSpyObj('ionicScrollDelegate', ['func1', 'func2']
controller = $controller('timeInOutController', {
$scope: scope,
$filter: filter,
$ionicScrollDelegate: ionicScrollDelegate
});
}));
describe('#date setting', function(){
...
});
});
})();
You can find more about spies via jasmine's documentation

You need to create mock objects for all dependencies your controller is using.
Take this controller as an example:
angular.module('app.module', [])
.controller('Ctrl', function($scope, $ionicLoading) {
$ionicLoading.show();
});
Here you are using the $ionicLoading service, so if you want to test this controller, you have to mock that object specifying the methods you're using in the controller:
describe('Test', function() {
// Mocks
var $scope, ionicLoadingMock;
var ctrl;
beforeEach(module('app.module'));
beforeEach(function() {
// Create $ionicLoading mock with `show` method
ionicLoadingMock = jasmine.createSpyObj('ionicLoading', ['show']);
inject(function($rootScope, $controller) {
$scope = $rootScope.$new();
ctrl = $controller('Ctrl', {
$scope: $scope,
$ionicLoading: ionicLoadingMock
});
});
});
// Your test goes here
it('should init controller for testing', function() {
expect(true).toBe(true);
});
});

update angular model from a service

angular.module('app.services', []).service("test", function($http, $rootScope){
this.test=function(){
$rootScope.name="test1";
};
};
angular.module('app.controllers', []).controller('TestController', function ($scope, test) {
test.send();
})
I dont get an error but the changes don't get applied to the UI. I tried $scope.apply() and got an error.

We need to tell Angular which modules your module depends on, In our case the main module is app.controllers.
To call service from different model we need tell to controller where is our service:
['app.services']
JS
var appServices = angular.module('app.services', []);
var appCtrl = angular.module('app.controllers', ['app.services']);
appServices
.service("test", function ($http, $rootScope) {
this.send = function () {
$rootScope.name = "test1";
};
});
appCtrl.controller('TestController', function ($scope, test) {
test.send();
});
Demo Fiddle

I think you should change ".service" by ".factory".
As I can see in the creating services docs there are 3 ways of creating custom services. One of then is using factory way, as the following:
var myModule = angular.module('myModule', []);
myModule.factory('serviceId', function() {
var shinyNewServiceInstance;
//factory function body that constructs shinyNewServiceInstance
return shinyNewServiceInstance;
});
Hope to help.

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