Ajax Knowledge summarization __ajax

1. Get Data using XMLHttpRequest: Open () and send () open (Method,url,anync)
Method:get/post. URL: Address Anync: Submit method, True indicates asynchronous/false represents synchronous Send (String)
If the submission is get,string=null if the submission is post,string= information that needs to be sent

Add
//Set HTTP header information, must be placed between open and send.

Request.setrequestheader (");

//
//

2.XMLHttpREquset Get a response

ResponseText	gets the response data returned as a string
Responsexml	Gets the response data returned in the form of XML
Stastus and StatusText	Returns an HTTP status code as a number and text
Getallresponseheader	Get all response headers
getResponseHeader	The value of a field in a query response

Readystatus Property

The

4	request is complete and the response is ready
0	The request has not been initialized and open has not yet been invoked
1	The server has established a link and open has been called
2	Request received, receive header information
3	In request processing, a response principal is received

Sample

Sends a request and processes--js--
//commits with a GET method, executes the asynchronous commit to the server.php
function () {
    var request=new xmlhttprequest ();
    Request.open ("Get", "server.php", true);
    Request.send ();
    Verify
    request.onreadystatechange=function () {
        if (request.readystatus===4&) by Onreadystatuschange event &request.status===200)
        {
            //If the request succeeds, this part of the Operation
        }else{
            alert ("Error occurred" +request.readystatus);
        }
    }
}

//Add, modify--js--//Submit with Post, execute asynchronous commit to server.php function () {var request=new xmlhttprequest ();
    Request.open ("POST", "server.php", true); Suppose you get data from the form var data= "name=" +document.getelementbyid (' name '). Value + "&age=" +document.getelementbyid (' age '). V
    Alue;
    Set HTTP header information Request.setrequestheader ("Content-type", "application/x-www-form-urlencoded");
    Post mode submission information request.send (data); Verify Request.onreadystatechange=function () {if (request.readystatus===4&&request) by Onreadystatuschange event
        . status===200) {//If the request succeeds, this part of the Operation}else{alert ("Error occurred" +request.readystatus); }
    }
}