Ajax BASICS (I)

I,Ajax Introduction

1. Ajax

Ajax =AsynchronousJavascriptAndXML(Asynchronous JavaScript and XML)

AjaxNot a newProgramming LanguageIs used to create better, faster, and more interactiveWebApplicationProgram.

Pass Ajax , Your Javascript Available Javascript Of XMLHttpRequest Object to directly communicate with the server. Through this object, Your Javascript When the page is not reloaded Web The server exchanges data.

AjaxIn the browser andWebAsynchronous Data Transmission (HTTPIn this way, the webpage can request a small amount of information from the server, rather than the whole page.

AjaxIt can make Internet applications smaller, faster, and more friendly.

AjaxIs an independentWebBrowser Technology of server software.

2. Ajax Based onWeb Standard

AjaxBased on the followingWebStandard:

• Javascript

• XML

• Html

• CSS

3. Ajax UseHTTP Request

In the traditional Javascript In programming, if you want to get any information from a file or database on the server, or send information to the server, you must use Html Form to server Get Or Post Data. The user needs to click " Submit " Button to send / Obtain the information and wait for the response from the server. Then, a new page loads the result.

Since the server returns a new page every time the user submits the input, the traditionalWebApplications become slow and unfriendly.

Exploitation Ajax , Your Javascript Will pass Javascript Of XMLHttpRequest Object to directly communicate with the server.

UseHTTPRequest,WebPage can be requested from the server and get a response from the server without loading the page. The user can stay on the same page. He or she does not notice that the script has requested the page in the background or sent data to the server.

4. XMLHttpRequest Object

UseXMLHttpRequestObject,WebDevelopers can update the page from the server after the page has been loaded!

In 2005 Year Ajax Quilt Google Open ( Google suggest ).

Google Recommended XMLHttpRequest Object To create a dynamic Web Interface: when you start Google In the search box, Javascript These words are sent to a server, and the server returns a series of search suggestions.