We live in a world where there is a dramatic increase in demand for almost everything. Taking this in the website context, there is a rise in users’ demand when it comes to responsiveness, aesthetics, and user-friendliness. To keep up with the pace, we develop new techniques. One such technique is AJAX, which stands for Asynchronous JavaScript and XML.
What is Ajax?
As the name suggests, this programming concept uses technologies such as XML (Extensible Markup Language), HTML (HyperText Markup Language), and CSS (Cascading Style Sheets). It also utilizes DOM (Document Object Model), XMLHttpRequest, and JavaScript. Using AJAX lets you update parts of your web pages by exchanging data to and from the server/database without reloading the page. That way, your web page is updated asynchronously and dynamically. To understand what AJAX is all about, let’s take a look at its advantages and disadvantages.
Advantages of AJAX
Initially, we didn’t have a medium through which the client-side of the web application could communicate with the server. Then we developed the AJAX concept, which solved our problem. Now, using AJAX, the client and server can remain in communication without the need for a page reload. The following are several other advantages of AJAX:
1. Ajax improves performance
AJAX is used to retrieve or save data to and from the server without having to post the complete page. This way, you only perform a part instead of the complete postback. The obvious advantage of partial postback is that you minimize the network utilization, which is great for performing the operations quickly. Additionally, since we are sending only required information, this eliminates the load on the server, eventually reducing server traffic. In other words, AJAX is used to make callbacks, which enhances performance significantly.
2. Asynchronous processing
You can use AJAX to create asynchronous connections, where users can interact on the front end without waiting for replies from the server. This way, you can make asynchronous calls to the webserver. You don’t have to wait before taking another action on the web page. To understand this better, let’s take an example of form validation. There are different fields users have to fill out in a form before clicking on the Submit button to validate the data. With the introduction of AJAX, you can validate the data in real-time. That’s how your data is validated as you start entering it.
3. Improves response time
Considering we are only transmitting required data to the server, the improvement in responsiveness comes as no surprise. In fact, AJAX is popularly used by developers to build responsive web pages. Retrieving only required data reduces the bandwidth usage, which also improves load speed, all the while boosting response time.
4. Reduces bandwidth usage
One of the most frustrating issues that plague a website is the server’s bandwidth. Gratefully, AJAX is well-equipped to handle such issues, as it reduces bandwidth usage significantly. Reducing bandwidth directly impacts a website’s performance as the load speed increases. But how does AJAX do so? Simple, by making the best use of a server’s bandwidth. It fetches particle contents instead of transmitting the entire web content as one. Hence, AJAX can help users to transport data to and from a database without reloading the webpage.
5. Multi-browser support
AJAX is supported by commonly used major internet browsers. A few of these browsers include Microsoft Internet Explorer 5 and above, Mozilla Firefox 1.0 and higher, Opera 7.6 and newer, and Apple Safari 1.2 and above. The increased compatibility of AJAX with various browsers ensures web pages perform the same way across different web environments.
6. Enhances user experience
As a user, you expect websites to offer you a faster browsing experience. The websites using AJAX techniques allow you to go through parts of the web pages without having to reload the page. It provides convenience and at the same time makes the website highly interactive. Take Google Search for example. As you start typing into the search bar, Google uses AJAX to show the common results. In other words, we can use AJAX to build auto-complete tools that show suggestions in the drop-down menu or list. Furthermore, the improved user experience is good news for businesses as it increases their conversion rate.
Disadvantages of AJAX
The advantages were quite convincing, weren’t they? But before you decide to adopt this technique, let’s quickly take a look at its downsides. Here are some drawbacks of using AJAX:
1. Dependency
You cannot run AJAX procedures on any browser. The reason: it is dependent on JavaScript. Therefore, the browser should support JavaScript or XMLHttpRequest. Otherwise, browsers that don’t support XMLHttpRequest or JavaScript objects won’t be able to interpret AJAX-enabled pages accurately. Also, some browsers have this functionality disabled, negatively impacting the execution. Finally, using the AJAX technique requires you to possess knowledge of JavaScript. In fact, these are the disadvantages of JavaScript in general.
2. Indexing problems
The importance of search engines cannot be underestimated. Hence, websites focus on enhancing their SEO (Search Engine Optimization). You can enjoy the perks of improved performance and speed with AJAX, but they come at a cost. Unfortunately, the search engine cannot index AJAX pages. Thus, you can forget about getting indexed by Google or other search engines when you develop web applications using AJAX.
3. Server inaccessibility
You cannot fetch information from other servers when using AJAX. The reason lies in the fact an XMLHttpRequest object can fetch information only from those servers pages are hosted on. This is to say, fetching information from another server is not possible in AJAX.
4. Debugging difficulties
The debugging process can be quite tricky in AJAX requests/responses. Moreover, the error messages aren’t robust either. This further increases the complexity of understanding the root of the problem. The error message should provide a context to develop solutions. Additionally, you will face browser Back button difficulties while using AJAX-enabled web pages. AJAX requests may not be registered within the browsing history. Therefore, when you press Back/Return, you’ll be redirected to the last full page instead of the last state.
5. Security issues
AJAX is open-source, so the code is available to anyone. This introduces security risks. Also, the data gets stored in the users’ browsers, where it is made available and can be accessed easily. Furthermore, AJAX makes calls to a server that includes database details. This is to say, the page source exposes the functionality of AJAX. Data serialization is another security issue. In that case, browsers invoke AJAX calls and if these calls are manipulated, they will be forced to execute scripts. These scripts can be malicious, putting the security of the users at risk.
6. XMLHttpRequest is a Double edged sword
AJAX uses XMLHttpRequest widely for sending and receiving requests to its web pages. It is because XMLHttpRequest helps AJAX to implement various techniques during web development. Now, this request transports XML data to and from a webpage with the aid of HTTP. But this over-reliance on XMLHttpRequest can bite the developers if the user relies on any of the web browsers that either blocks or don’t support JavaScript or XMLHttpRequest. If one tries to load an AJAX web page on such a browser, it will only result in a blank.