Ajax Study Notes

What Is Ajax:

Ajax covers all technologies that allow the browser to communicate with the server without refreshing the current page, JavaScript, Dom, xhr (XMLHttpRequest), and so on.

What can Ajax do? What are the characteristics:

1. Ajax allows asynchronous operations.
2. Ajax applications are affected by browser differences.
3. Ajax is a client technology that has nothing to do with the server.

Ajax-related web desktop application models can be referred to: http://www.ajaxpatterns.org
 
What Ajax is used:

Ajax is used to provide a rich user experience in the client browser.

Core Ajax technologies:

XMLHTTPRequest object is the key to Ajax technology. It has not yet become W3C standard, but popular browsers support it. microsoft Internet Explorer uses it as an ActiveX object, while other browsers use it as a built-in JavaScript Object. you can use the followingCodeTo create an XMLHTTPRequest object for different browsers:

VaR XMLHTTP;

Function createxmlhttprequest ()
{
If (Windows. activexobject)
{
XMLHTTP = new activexobject ("Microsoft. XMLHTTP ");
}
Else if (window. XMLHttpRequest)
{
XMLHTTP = new XMLHttpRequest ();
}
}

What is W3C Dom?

The Document Object Model (DOM) is a programming interface unrelated to the platform and language.ProgramAnd the script dynamically accesses and updates the content, structure and style of the document. The document can be further processed, and the processing result can be stored back to the provided page.