How to apply AJAX Asynchronous callback
This article is a detailed introduction to "how to apply AJAX asynchronous callback". The content is detailed, the steps are clear, and the details are properly handled. I hope this article "how to apply AJAX asynchronous callback" can help you solve your doubts. Let's go deeper and learn new knowledge together with the ideas of Xiaobian.
Asynchronous AJAX
In addition to setTimeout functions, asynchronous callbacks are widely used in AJAX programming.
XMLHttpRequest is often used to request XML or JSON data from a remote server. A standard XMLHttpRequest object often contains multiple callbacks:
examples
var xhr = new XMLHttpRequest();
xhr.onload = function () {
//output received text data
document.getElementById("demo")[xss_clean]=xhr.responseText;
}
xhr.onerror = function () {
document.getElementById("demo")[xss_clean]="Request Error";
}
//Send asynchronous GET requests
xhr.open("GET", "https://www.runoob.com/try/ajax/ajax_info.txt", true);
xhr.send();
The onload and onerror properties of XMLHttpRequest are functions that are called when its request succeeds and when its request fails, respectively. If you use the full jQuery library, you can also use asynchronous AJAX more elegantly:
examples
$.get("https://www.runoob.com/try/ajax/demo_test.php",function(data,status){
alert("data: " + data + "\nstatus: " + status);
});
Read here, this article "AJAX asynchronous callback how to apply" article has been introduced, want to master the knowledge points of this article also need to practice to understand, if you want to know more related content of the article, welcome to pay attention to the industry information channel.
