How to get started with RequireJS and What is it?

Modular programming is used to break large applications into smaller blocks of manageable code. Module-based coding eases the effort for maintenance and increases reusability. However, managing dependencies between modules is a major concern developers face throughout the application development process. RequireJS is one of the most popular frameworks around for managing dependencies between modules. Basically, RequireJS is an essential loader, which is utilized to load the JavaScript files. It is a framework to oversee conditions between JavaScript documents, and in measured programming, all the functionality is isolated in various modules, so RequireJS is the best instrument to collect different JavaScript files from various modules, by which it assists with improving the speed and quality of your code.

Why RequireJS

There are a few reasons:

• In a huge application, a lot of JavaScript files are required, and each script tag needs a request.
• You need to place them in the same order in which they are called; for example, a file that is dependent on others should be loaded after the dependent ones.

How to use

You can download the file.

Take an example path of your JavaScript files:

Now you just need to add a <script> tag in your HTML file to include the Require.js file.

You can place this script tag at the head or at the bottom of the phtml file.

Here, main.js is the main JavaScript file of my application.

The above <script> tag by the data-main attribute is required.JS will start initialization of files. (path of the folder/file name).

data-main is used when you have only a single entry point; if you have multiple entry points, then you can include it by HTML also.

Now in main.js we have the following code:

In RequireJS all the code is written under requirejs() or define() functions.

Here, it searched for “example.js” in the same folder and took example as an object of the example.js file to call the functions of example.js.

You can also include files from different folders.

Advantages of RequireJs

• Lazy loading
• Reduce code Complexity in large applications.
• Assembly of different split files at compile time
• Less HTTP requests
• No need to define them in some proper order

Hope this blog will help you to understand the basics of RequireJS.