Categories: Javascript

AngularJS – Different Ways to Declare Controllers

The article represents various ways of declaring a controller along with code examples. Please feel free to comment/suggest if I have missed on any key aspects.Following are two different ways in which controllers can be declared:
  • Using “as aliasName” in ng-controller. Example: ng-controller=”HelloCtrl as ctrl”
  • Just the controller name. In this strategy, $scope object is bound to data and methods. Example: ng-controller=”HelloCtrl”

 

Using “as aliasName” in ng-controller (Recommended Way)

Using “as aliasName” specifier when defining the controller in ng-controller directive. The methods and properties can be bound on to the controller using “this” keyword. There are benefits of binding properties directly to the controller and thus, it is the recommended way (best practice) to declare the controller using “as alias” method. Following are some of the benefits:

  • In case of multiple controllers, one knows which controllers are accessed in reading the template.
  • Enhanced readability, in general
  • Helps create controller using prototypal inheritance.

Following is how view code looks like. Note the “as ctrl” and then, “ctrl.name”

<div ng-controller="HelloCtrl as ctrl">
    <input type="text" name="name" ng-model="ctrl.name"/>
</div>

Following is how the controller looks like:

angular.module( "helloApp", [] )
    .controller( "HelloCtrl", function() {
        this.name = '';
    }]);

 

Injecting the Scope Object into the Controller (Rookies Way)

This is most common and popular way of working with the controller. For rookies to quickly get on board, this may be the recommended way.

In this strategy, the properties and methods get bound as scope properties and methods and can be later accessed on scope object within the controller object. This strategy requires $scope object to be injected.

Following is how view code looks like. Note the absence of “as” in the ng-controller directive and “ctrl.” alias in ng-model directive.

<div ng-controller="HelloCtrl">
    <input type="text" name="name" ng-model="name"/>
</div>

Following is how the controller looks like. Notice that $scope is injected and the model is bound to $scope object.

angular.module( "helloApp", [] )
    .controller( "HelloCtrl", [ '$scope', function( $scope ) {
        $scope.name = '';
    }]);

[adsenseyu1]

Ajitesh Kumar

I have been recently working in the area of Data analytics including Data Science and Machine Learning / Deep Learning. I am also passionate about different technologies including programming languages such as Java/JEE, Javascript, Python, R, Julia, etc, and technologies such as Blockchain, mobile computing, cloud-native technologies, application security, cloud computing platforms, big data, etc. I would love to connect with you on Linkedin. Check out my latest book titled as First Principles Thinking: Building winning products using first principles thinking.

View Comments

  • another way is registering a controller using a $controllerProvider. Then use the $controller service to create it. You can pass the $scope as parameters to $controller service.

Share
Published by
Ajitesh Kumar
Tags: angularjs

Recent Posts

Agentic Reasoning Design Patterns in AI: Examples

In recent years, artificial intelligence (AI) has evolved to include more sophisticated and capable agents,…

1 month ago

LLMs for Adaptive Learning & Personalized Education

Adaptive learning helps in tailoring learning experiences to fit the unique needs of each student.…

1 month ago

Sparse Mixture of Experts (MoE) Models: Examples

With the increasing demand for more powerful machine learning (ML) systems that can handle diverse…

2 months ago

Anxiety Disorder Detection & Machine Learning Techniques

Anxiety is a common mental health condition that affects millions of people around the world.…

2 months ago

Confounder Features & Machine Learning Models: Examples

In machine learning, confounder features or variables can significantly affect the accuracy and validity of…

2 months ago

Credit Card Fraud Detection & Machine Learning

Last updated: 26 Sept, 2024 Credit card fraud detection is a major concern for credit…

2 months ago