How to abort Ajax requests using jQuery ?

To abort an Ajax request using jQuery, you can utilize the jqXHR object returned by jQuery’s Ajax methods (e.g., $.ajax(), $.get(), $.post()). Here’s a step-by-step guide:

1. Store the `jqXHR` Object

When initiating the Ajax request, store the returned jqXHR object in a variable:

let xhr;

function makeRequest() {
  xhr = $.ajax({
    url: 'https://api.example.com/data',
    method: 'GET',
    success: function(response) {
      console.log('Success:', response);
    },
    error: function(jqXHR, textStatus, errorThrown) {
      if (textStatus === 'abort') {
        console.log('Request aborted');
      } else {
        console.error('Error:', errorThrown);
      }
    }
  });
}

2. Abort the Request

Call .abort() on the stored jqXHR object to cancel the request:

function abortRequest() {
  if (xhr) {
    xhr.abort(); // Aborts the ongoing request
    xhr = null;  // Reset the variable
  }
}

3. Example Usage

HTML:

<button onclick="makeRequest()">Start Request</button>
<button onclick="abortRequest()">Abort Request</button>

Behavior:

Clicking “Start Request” triggers the Ajax call.
Clicking “Abort Request” cancels the ongoing request (if active).

Key Notes

Abort Detection: The error callback checks textStatus === 'abort' to handle intentional cancellations.
Reset Variable: Set xhr = null after aborting to avoid redundant calls.
Shorthand Methods: Works with $.get(), $.post(), etc.:

  xhr = $.get('https://api.example.com/data', function(response) {
    console.log('Success:', response);
  });

Advanced: Abort All Pending Requests

Store multiple jqXHR objects in an array to abort all active requests:

const pendingRequests = [];

function makeRequest() {
  const xhr = $.ajax({ ... });
  pendingRequests.push(xhr);
}

function abortAllRequests() {
  pendingRequests.forEach(xhr => xhr.abort());
  pendingRequests.length = 0; // Clear the array
}

Why This Works

The jqXHR object wraps the native XMLHttpRequest and provides an .abort() method.
Aborting terminates the network request and triggers the error callback with textStatus: 'abort'.

Use this approach to manage long-running or unnecessary requests efficiently!

1. Store the jqXHR Object