jQuery ajaxSend Event

Posted in jQuery Tutorial

Updated on May 20, 2024

By Mari Selvan

👁️ 7 - Views

⏳ 4 mins

💬 0

Photo Credit to CodeToFun

🙋 Introduction

In web development, AJAX (Asynchronous JavaScript and XML) plays a crucial role in creating dynamic and interactive web applications. jQuery provides a convenient way to handle AJAX requests and responses through various events, one of which is the ajaxSend event. Although the .ajaxSend() method has been deprecated, jQuery recommends using the .on() method instead for event handling.

In this guide, we'll explore the ajaxSend event, its syntax using .on(), and how you can effectively utilize it in your web projects.

🧠 Understanding ajaxSend Event

The ajaxSend event is triggered whenever an AJAX request is about to be sent. It provides an opportunity to modify the XMLHttpRequest object (xhr) before it is sent. This event is particularly useful for tasks like showing loading indicators, modifying headers, or performing any pre-processing tasks before the request is dispatched.

💡 Syntax

The syntax for the ajaxSend event is straightforward:

syntax.js

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$(document).on("ajaxSend", function(event, xhr, options) {
  // Your event handling code here
});

Parameters:

event: The event object.
xhr: The XMLHttpRequest object.
options: The options object passed to the AJAX request.

📝 Example

Displaying Loading Indicator:

You can use the ajaxSend event to display a loading indicator whenever an AJAX request is initiated. For instance:
example.js
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```
$(document).on("ajaxSend", function(event, xhr, options) {
  $("#loadingIndicator").show();
});
```
This code will show an element with the ID loadingIndicator whenever an AJAX request is sent.
Modifying Request Headers:

You may need to modify request headers based on certain conditions. Here's how you can achieve that:
example.js
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```
$(document).on("ajaxSend", function(event, xhr, options) {
  xhr.setRequestHeader("Authorization", "Bearer YourAccessToken");
});
```
This will add an authorization header to every AJAX request sent from your application.
Logging Request Details:

You can also log details of AJAX requests for debugging purposes:
example.js
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```
$(document).on("ajaxSend", function(event, xhr, options) {
  console.log("Request URL:", options.url);
  console.log("Request Type:", options.type);
});
```
This will log the URL and type of each AJAX request to the console.

🎉 Conclusion

The ajaxSend event provides a convenient hook for performing tasks before AJAX requests are sent. By using the .on() method to handle this event, you can efficiently manage AJAX interactions in your web applications.

Whether it's showing loading indicators, modifying headers, or logging request details, the ajaxSend event empowers you to enhance the user experience and streamline AJAX functionality.