Ajax HTTP Request mode

1. Setting Up Xmlhttprequest/msxml2.xmlhttp objects

This should be the most common way, very easy to use, can really connect XML objects,

Can be submitted by "POST" "GET",

However, cross-domain is not supported in Firefox

2. Use DOMDocument object, but IE and Firefox are very poor,

The request can be made through the object's load (URL), which is, of course, only a Get mode,

The returned result can only be XML, with the same onreadystatechange processing callback,

Cross-domain is not supported in Firefox

3. Use the IFRAME to make a request, set the SRC attribute, make a GET request,

The. Document.body of the pass-through object takes the return value, the. OnLoad processing callback,

However, the cross-domain is not supported in Firefox and Iframe.document is inaccessible in Firefox.

4. Dynamically create <script> tag, set src attribute, issue get request,

The benefit of this request is that it executes the returned result as a script, and supports cross-domain in Firefox.

Processing the callback as long as the result of the request service is a script,

If the return result is response (0,{},0), the response (0,{},0) is called when the request ends

Where the parameter can return an object in this manner {a:1,b:function () {}}.

But dealing with XML can be a bit cumbersome.

5. Use the script (new Image ()). src = "url"; This also makes it possible to make a GET request, but cannot process the return value.

Can be used when you don't need to process the return results.