AJAX, short for Asynchronous JavaScript and XML, is not a programming language. Rather, it is a set of instructions and technologies that allows websites to update or render content without reloading web pages.
To understand AJAX, we have to look at how scripts are loaded: synchronously and asynchronously.
In synchronous loading, scripts are executed based on their sequence, starting from the <head> tag. When using this technique, users cannot interact with the web page until all the scripts are executed.
On the other hand, asynchronous loading can process multiple scripts at the same time, regardless of its order within a sequence. As a result, data can be exchanged continuously without interfering with user experience.
Asynchronous loading is a staple in many modern-day web applications. You’d see it a lot when browsing emails, commenting on social media, filling contact forms, or clicking a popup. Each time new data appears (i.e. new messages in your inbox), you can immediately see the changes without refreshing the whole page.
In this article, I will explain the ins and outs of AJAX as well as its benefits. Later, I will also recommend several websites that provide resources on how to implement AJAX. So stick around and read on.
How does AJAX work?
AJAX is a technique used on the client-side, with JavaScript as the main programming language. However, before we get into the specifics of how this technology works, let’s take a look at its components first.
This method is developed to comply with internet standards, which is a protocol for displaying and transferring data over the internet, approved by the Internet Engineering Task Force. As such, it is built on several basic components:
- XMLHttpRequest object — the component that sends JavaScript requests to a database. The JavaScript’s fetch() function is widely regarded as the better, modern alternative to the object.
- Data transfer format — while an AJAX technology can retrieve data transmission in an XML format, nowadays the JSON format is more commonly used because it’s more compact. It also accepts HTML snippets and plain texts.
- Data representation — information that has been retrieved is displayed and structured with a JavaScript Document Object Model and styled with CSS so users can interact with it.
Now that you know what AJAX technologies consist of, let’s take a look at the diagram below:
When a visitor performs an action like scrolling down a page, typing an input, or clicking a button, JavaScript generates an XMLHttpRequest object (or execute the fetch function). This object then requests a web server to fetch only the necessary information from a database.
After the database finishes processing the request, it responds back. The information is transmitted using a format understandable to both machines and humans, typically XML or JSON.
Before reaching the web page though, an AJAX engine will read the response, making sure the information is displayed correctly, and seamlessly load it to the browser.
And that’s how it works. In the next section, let’s take a look at the advantages of this web programming method.
What are the Benefits of AJAX?
There are plenty of good reasons why AJAX serves as a backbone to many modern web development practices. Here are some of them:
- Efficiency — AJAX allows sending data in small packets because only a portion of the content is needed. It results in more efficient bandwidth usage.
- Website speed — thanks to the smaller portions of data, the delivery time is shortened as well. Plus, the server and the client’s processes are separated from each other, improving the processing speed on both sides.
- Better user experience — because the user does not experience any downtime while the web page is dynamically modified, AJAX is great for improving user experience. The process also makes site navigation and interactions look smoother.
- Compatibility — aside from JavaScript, AJAX works on top of standard web programming languages such as PHP and C, as well as frameworks like ASP.net.
5 Sites to Learn AJAX
Since the use of AJAX has become a commonplace in modern web programming, you might want to learn the methods and its implementations.
To do that, you first need some functioning knowledge of HTML5, JavaScript, and JavaScript Document Object Model or at least a basic idea of how data is structured on a webpage.
Then make sure you follow along with the exercises provided by the tutorials. Remember, the more you practice, the better your skills will be.
Now, without further ado, here are the top places I’d recommend if you want to master AJAX:
- W3Schools — a good place to familiarize yourself with the basics of AJAX. Aside from that, this website also introduces you to related concepts, technologies, and programming languages with the help of interactive examples.
- Udemy — this learning platform offers free three-part introductory lessons on AJAX. The materials are packaged in an easy-to-follow video format. However, you need to pay for longer, more in-depth courses.
- YouTube — it’s a great place for self-taught developers, as you can easily find video playlists dedicated to learning AJAX.
- The official jQuery documentation — the guide thoroughly and clearly explains how AJAX works, as well as provide other useful references relevant to the subject.
- Mozilla’s AJAX guide — if you already have some experience in coding, you can check this documentation out. It offers a comprehensive explanation of AJAX and its implementations.
Conclusion
To summarize, AJAX is a combination of multiple methods and technologies to enhance user experience. It’s a common JavaScript practice that typically uses an XML format for data transactions, although JSON is more widely used these days.
Asynchronicity is its main trait, as it can continuously run a script independently from other scripts within a sequence. Thanks to that, data can load seamlessly without reloading the entire page from scratch.
Some of the benefits of this method are bandwidth efficiency, speed, compatibility, and improved user experiences. I also recommended several excellent platforms to learn AJAX. Hopefully, this article was useful.
Do you have any questions or thoughts on this? Leave a comment down below.
Leave a Reply