jQuery ajaxStart Event

Posted in jQuery Tutorial

Updated on May 20, 2024

By Mari Selvan

👁️ 9 - Views

⏳ 4 mins

💬 0

Photo Credit to CodeToFun

🙋 Introduction

In web development, AJAX (Asynchronous JavaScript and XML) is a powerful technique for creating dynamic and interactive web applications. jQuery simplifies AJAX requests with its comprehensive set of methods and events. One such event is ajaxStart, which is triggered when an AJAX request begins. Despite being deprecated, understanding this event is crucial for handling AJAX-related tasks effectively.

In this guide, we'll explore the ajaxStart event, its replacement using .on(), and provide examples to illustrate its usage.

🧠 Understanding ajaxStart Event

The ajaxStart event in jQuery is triggered when the first AJAX request begins, providing an opportunity to perform tasks such as showing loading indicators or disabling user interactions during the request cycle. It was commonly used in previous versions of jQuery but has since been deprecated in favor of the .on() method.

💡 Syntax

The syntax for the ajaxStart event is straightforward:

syntax.js

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$(document).on("ajaxStart", handler);

syntax.js

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$(document).on("ajaxStart", eventData, handler);

📝 Example

Displaying Loading Indicator:

Suppose you want to display a loading indicator whenever an AJAX request starts. You can achieve this using the ajaxStart event:
example.js
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```
$(document).on("ajaxStart", function() {
  $("#loadingIndicator").show();
});
```
In this example, #loadingIndicator is a placeholder for the loading indicator element in your HTML.
Disabling User Interactions:

You may also want to disable certain user interactions during AJAX requests to prevent unintended actions. Here's how you can do it:
example.js
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```
$(document).on("ajaxStart", function() {
  $("button").prop("disabled", true);
});
```
This code disables all buttons on the page when an AJAX request starts.
Combining with Other Events:

You can combine the ajaxStart event with other AJAX-related events to create more complex behaviors. For instance, you can show a loading indicator only for specific AJAX requests:
example.js
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```
$(document).on("ajaxStart", function() {
  $("#specificRequestIndicator").show();
});
$(document).on("ajaxStop", function() {
  $("#specificRequestIndicator").hide();
});
```
Here, #specificRequestIndicator represents a loading indicator specific to a certain AJAX request.

🎉 Conclusion

While the ajaxStart event has been deprecated in jQuery, understanding its functionality and replacement with .on() is essential for effective AJAX handling in web development. By leveraging this event, you can create more responsive and user-friendly web applications, providing visual cues to users during asynchronous request cycles.

Experiment with different scenarios and integrate the ajaxStart event into your projects to enhance the user experience.