What is a JavaScript framework? How can it be called a framework?

JavaScript is a powerful language in its own right, and you don’t need additional frameworks to create Rich Internet Applications (RIA). However using JavaScript is not easy, mainly due to the complexities that arise from supporting multiple web browsers. As with HTML and CSS, different browsers have different implementations of JavaScript. Making JavaScript code cross-browser compatible is a nightmare.

A JavaScript framework or library is a set of tools and functions that make it easy to generate cross-browser compatible JavaScript code. Each library has been reliably tested on modern versions of many popular web browsers, so you can use these frameworks with confidence that your JavaScript-based RIAs will perform similarly across browsers and platforms. Work.

In addition to solving cross-browser issues, using JavaScript frameworks makes it easier to write code that retrieves, traverses, and manipulates DOM elements. Not only do they provide shortcut functions for obtaining references to DOM elements, but they also allow DOM traversal functions to find parent elements, child elements, and sibling elements at any depth in a daisy-chaining manner. Finally, the framework also provides a series of functions to make it easier to manipulate these objects. You can change, add or remove the content itself; or use CSS style classes to change the appearance of the element.

Another important feature of the framework is its improved event handling support. Since different browsers have different implementations, cross-browser event handling will be very difficult. Therefore JavaScript frameworks usually encapsulate browser events and provide a useful set of cross-browser compatible functions for processing. Some frameworks also provide a set of standard keyboard codes to represent keyboard-based events (e.g. Escape key pressed, Return key pressed, cursor key pressed, etc.).

All of these features are very useful, but there is one feature of the JavaScript framework that has been very important to its recent popularity — support for Ajax. As with many other aspects of JavaScript, each web browser tends to support Ajax differently, which complicates handling Ajax in a way that is supported across all web browsers. Almost all JavaScript frameworks include some form of Ajax library support, typically providing Ajax request and response objects, as well as helpers for evaluating responses, updating DOM elements, and querying for specific requests.

Typical Features of JavaScript Frameworks

Now, let’s take a look at the useful features that most JavaScript frameworks have. Includes:

1. Selector
2. DOM traversal
3. DOM operation
4. Utility function
5. Event handling Ajax

When explaining each feature, I will use one or several of the following JavaScript frameworks as examples: Prototype, jQuery, YUI, ExtJS, and MooTools. Although the implementation and syntax of each framework are different, the concepts are the same. Each framework has a detailed API reference that helps you understand how to use features in that particular library.

For more related tutorials, please visit JavaScript Basics Tutorial