AJAX (Asynchronous JavaScript And XML)

JavaScript Tutorials - Herong's Tutorial Examples

∟AJAX (Asynchronous JavaScript And XML)

This chapter provides a quick introduction on AJAX (Asynchronous JavaScript And XML). Topics include what introduction to AJAX, XMLHttpRequest API, requests, responses, properties, methods and events; ; examples to send synchronous and asynchronous requests, to parse responses as JSON or other objects, and to create event handlers for receiving responses, reporting process progress, checking HTTP status.

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What Is AJAX

XMLHttpRequest Object and API

XMLHttpRequest Events and Handlers

AJAX Example - Simple Synchronous Requests

AJAX Example - Asynchronous Requests and Events

AJAX Example - Progress and Status Checked

AJAX Example - JSON and Formatted Responses

Takeaways:

AJAX (Asynchronous JavaScript And XML) represents an approach of using the XMLHttpRequest API provided in Web browsers to update content dynamically without reloading the entire browser page.
XMLHttpRequest is an object type provided by Web browsers that allows you to send HTTP requests to and receiving response from the Web server.
ajax = new XMLHttpRequest(): Constructor to create a new XMLHttpRequest object.
ajax.open(method, url, async): Method to initialize a request with a given method, a URL of the Web server, an asynchronization flag: true or false.
ajax.send(body): Method to send an initialized request with the given request body to the Web server.
ajax.responseText: Property representing the response's body content as a text string.
ajax.onload: Property representing the handler function on the "load" event, fired when the response of the request is fully loaded.