Jquery Abort Ajax Request Before Sending Another

When it comes to handling multiple Ajax requests in jQuery, sometimes you might need to abort one request before sending another. This can be particularly useful in situations where you want to prevent unnecessary network traffic or ensure that only the most recent request is being processed. In this article, we'll explore how you can effectively abort an Ajax request in jQuery before sending a new one.

To start, let's consider a scenario where you have a web application that makes multiple Ajax calls to retrieve various pieces of data. If, for instance, you have a search functionality that triggers an Ajax request every time a user types in a search query, you may want to cancel any pending requests if the user types another query before the previous request completes.

One way to achieve this is by utilizing the `xhr` object that is returned by the `$.ajax()` function in jQuery. This object represents the underlying XMLHttpRequest in the browser and allows you to interact with the request, including aborting it.

let currentRequest = null;

function makeAjaxRequest(searchQuery) {
  if (currentRequest) {
    currentRequest.abort();
  }

  currentRequest = $.ajax({
    url: 'your-api-endpoint',
    method: 'GET',
    data: { query: searchQuery },
    success: function(response) {
      // Handle the response
    }
  });
}

In the code snippet above, we maintain a reference to the current Ajax request in the `currentRequest` variable. Before sending a new request, we check if there's an existing request and call the `abort()` method on it to cancel it. This ensures that only the most recent request is being processed.

It's important to note that aborting an Ajax request may not be instantaneous, especially if the request has already been sent to the server. The `abort()` method will attempt to cancel the request, but there may still be some network overhead. Make sure to handle the aborted request appropriately in your code.

Additionally, you can also handle the scenario where the request is aborted by adding an error callback to the `$.ajax()` function.

currentRequest = $.ajax({
  url: 'your-api-endpoint',
  method: 'GET',
  data: { query: searchQuery },
  success: function(response) {
    // Handle the response
  },
  error: function(xhr, status, error) {
    if (status === 'abort') {
      // Request was aborted
    } else {
      // Handle other errors
    }
  }
});

By including an error callback, you can distinguish between requests that were aborted intentionally and those that encountered other types of errors.

In conclusion, by leveraging the `xhr` object returned by jQuery's `$.ajax()` function and the `abort()` method, you can effectively manage and cancel Ajax requests before sending new ones in your web application. This approach can help improve the performance and user experience of your application by ensuring that only the most relevant data is fetched from the server.