Synchronizing Asynchronous Return Values with Ajax

General
1

Synchronizing Asynchronous Return Values with Ajax

When working with asynchronous JavaScript and XML (Ajax) requests, it’s often necessary to synchronize the return values to ensure that the data is processed correctly. In this context, we’ll explore how to achieve this using the $.Ajax function from the jQuery library.

The Problem: Asynchronous Return Values

By default, Ajax requests are asynchronous, meaning that the function will continue executing while the request is being processed. However, this can lead to issues when trying to access the return value, as it may be undefined or null. To overcome this challenge, we can set the async parameter to false, which will block the execution of the function until the request is complete.

The Solution: Synchronizing Return Values

Here’s an example of how to use the $.Ajax function to synchronize the return values:

$.Temp = function () {
  $.Ajax({
    url: SERVERURL + "Info",
    type: 'post',
    data: {
      userDevice: "web",
      sessionId: SESSIONID
    },
    async: false, // Synchronize the return value
    dataType: 'json',
    success: function (xhr) {
      var data = xhr.data;
      if (xhr.isSuccess == true) {
        if (data == null || data == "") {
          // Handle empty or null data
        } else {
          temporary = 0; // Process the data
        }
      } else {
        $.Alert("acquisition has failed!", 3);
      }
    },
    error: function (msg) {
      $.Alert('network error', 3);
    }
  });
  return temporary; // Return the synchronized value
}

Key Parameters

When using the $.Ajax function, it’s essential to understand the following parameters:

  • async: Set to false to synchronize the return value.
  • dataType: Specify the data type expected from the server, in this case, json.
  • success: Define a callback function to handle the successful response.
  • error: Define a callback function to handle any errors that may occur.

Example Use Case

To use the $.Temp function, simply call it and access the return value:

var result = $.Temp();
console.log(result); // Output: 0

By synchronizing the return values with Ajax, we can ensure that our applications handle data correctly and provide a better user experience.