AngularJS Toggle Class using ng-class Example

Hello readers, in this tutorial, developers will learn what AngularJS is and how to toggle the CSS class using the ng-class and ng-click angular directives.

1. Introduction

AngularJS is a JavaScript MVC or Model-View-Controller framework developed by Google that lets developers build well structured, easily testable, and maintainable front-end applications. Before we start with the creation of a real application using the angular framework, let us see the important parts of an angular application.

1.1.1 Templates

In angular, a template is an HTML with added markups. AngularJS library compiles the templates and renders the resultant HTML page.

1.1.2 Directives

Directives are the markers (i.e. attributes) on a DOM element that tell angular to attach a specific behavior to that DOM element or even transform the DOM element and its children. Most of the directives in the angular library start with the prefix ng. Below is the list of important directives that are available in the angular library.

  • ng-app: The ng-app directive is a starting point. If the AngularJS framework finds the ng-app directive anywhere in the HTML document, it bootstraps (i.e. initializes) itself and compiles the HTML template
  • ng-model: The ng-model directive binds an HTML element to a property on the $scope object. It also binds the values of AngularJS application data to the HTML input controls.
  • ng-bind: The ng-bind directive binds the AngularJS application data to the HTML tags
  • ng-controller: The ng-controller directive specifies a controller in the HTML element. This controller will add behavior or maintain the data in that HTML element and its child elements
  • ng-repeat: The ng-repeat directive repeat a set of HTML elements for each item in a given collection

1.1.3 Expressions

An expression is like a JavaScript code usually wrapped inside the double curly braces such as {{ expression }}. AngularJS library evaluates the expression and produces a result.

These new APIs make developer’s life easier, really! But it would be difficult for a beginner to understand this without an example. Therefore, let us create a simple application using the ng-class and ng-click angular directives.

2. AngularJS Toggle Class Using Ng-click Example

Here is a step-by-step guide for implementing this tutorial in the angular applications.

2.1 Tools Used

We are using Eclipse Kepler SR2, JDK 8 and Maven. Having said that, we have tested the code against JDK 1.7 and it works well.

2.2 Project Structure

Firstly, let’s review the final project structure if you are confused about where you should create the corresponding files or folder later!

AngularJS Toggle Class using ng-class - Application Project Structure
Fig. 1: Application Project Structure

2.3 Project Creation

This section will show how to create a Java-based Maven project with Eclipse. In Eclipse Ide, go to File -> New -> Maven Project.

AngularJS Toggle Class using ng-class - Maven Project
Fig. 2: Create a Maven Project

In the New Maven Project window, it will ask you to select project location. By default, ‘Use default workspace location’ will be selected. Just click on next button to proceed.

AngularJS Toggle Class using ng-class - Project Details
Fig. 3: Project Details

Select the ‘Maven Web App’ Archetype from the list of options and click next.

AngularJS Toggle Class using ng-class - Archetype Selection
Fig. 4: Archetype Selection

It will ask you to ‘Enter the group and the artifact id for the project’. We will enter the details as shown in the below image. The version number will be by default: 0.0.1-SNAPSHOT.

AngularJS Toggle Class using ng-class - Archetype Parameters
Fig. 5: Archetype Parameters

Click on Finish and the creation of a maven project is completed. If you see, it has downloaded the maven dependencies and a pom.xml file will be created. It will have the following code:


<project xmlns="" xmlns:xsi="" xsi:schemaLocation="">

Let’s start building the application!

3. Application Building

Let’s create an application to understand the basic building blocks of this tutorial.

3.1 Load the AngularJS framework

Since it is a pure JavaScript framework, we should add its reference using the <script> tag.

<script type="text/javascript" src=""></script>

3.2 Define the AngularJS application

Next, we will define the AngularJS application using the <ng-app>, <ng-controller> directives.


<div ng-app="app" ng-controller="ctrl">
	<button type="button" ng-click="someFunction()">Toggle</button>
	<div ng-class="myClass">
		Some text.

3.3 Complete Application

In this example, we will use the ng-click angular directive to call and execute a function on a button click. To illustrate further, we are displaying a sample text that will change its font-color on a button click. Complete the above steps and I will show you how to use the ng-class angular directive to change the font color on a button click. Let’s see the sample code snippet.


<!DOCTYPE html>
	    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
	    <title>AngularJS ToggleClass</title>
	    <!-- AngularJs File -->
	    <script type="text/javascript" src="resource/js/angular_v1.6.0.js"></script>
	    <!-- Bootstrap Css -->
	    <link rel="stylesheet" href="">
	    <script type="text/javascript">
		    var mainApp = angular.module("app", []);
		    mainApp.controller('ctrl', ['$scope', function ($scope) {
		    	$scope.myClass = { red: false };
		    	// Method to toggle the css class.
		    	$scope.toggleClass = function() {
		    	      $ = !$;
	    <style type="text/css">
	    	.red {
	    <div id="angularToggle" class="container">
	        <h1 align="center" class="text-primary">AngularJS - Toggle Class Example</h1>
	        <hr />
	        <!------ AngularJs Toggle CSS Class Example ------>
	        <div ng-app="app" ng-controller="ctrl">
	        	<button type="button" class="btn btn-outline-primary" ng-click="toggleClass()">Toggle</button>
				<div> </div>
	            <div id="divId" ng-class="myClass">
  					This text color can be changed on button toggle.

4. Run the Application

As we are ready for all the changes, let us compile the project and deploy the application on the Tomcat7 server. To deploy the application on Tomat7, right-click on the project and navigate to Run as -> Run on Server.

AngularJS Toggle Class using ng-class - Deploy Application on Tomcat
Fig. 6: How to Deploy Application on Tomcat

Tomcat will deploy the application in its web-apps folder and shall start its execution to deploy the project so that we can go ahead and test it in the browser.

5. Project Demo

Open your favorite browser and hit the following URL. The output page will be displayed.


Server name (localhost) and port (8082) may vary as per your Tomcat configuration.

AngularJS Toggle Class using ng-class - Application Output
Fig. 7: Application Output

Developers can click the Toggle button to change the font color of a sample text. That’s all for this post. Happy Learning!

6. Conclusion

In this section, developers learned how to create a simple angular application to change the font-color of a sample text using the ng-click directive. Developers can download the sample application as an Eclipse project in the Downloads section.

7. Download the Eclipse Project

This was an example of calling and executing a function to toggle the CSS class using the ng-click angular directive in the AngularJS framework.

You can download the full source code of this example here: AngularToggleClassNgClick


The author is graduated in Electronics & Telecommunication. During his studies, he has been involved with a significant number of projects ranging from programming and software engineering to telecommunications analysis. He works as a technical lead in the information technology sector where he is primarily involved with projects based on Java/J2EE technologies platform and novel UI technologies.
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