Talking about Ajax

One. What is Ajax?

Ajax is read without flush data.

Two. The principle of Ajax:

HTTP request method

1.get-used to get data (e.g. Browse posts)

2.post-for uploading data (e.g., user registration)

Three. Writing the AJAX request:

The idea of Ajax requests

1. Creating an Ajax Object

IE6 or more

var oajax=new xmlhttprequest ();

IE6

var oajax=new activexobject ("Microsoft.XMLHTTP");

Resolving IE6 compatibility issues

var oajax=null;

if (window. XMLHttpRequest)
{
Oajax=new XMLHttpRequest ();
}
Else
{
Oajax=new ActiveXObject ("Microsoft.XMLHTTP");
}

2. Linked Servers

Open (method, URL, whether asynchronous)
Oajax.open (' GET ', ' abc.txt ', true);//Where abc.txt is the path

3. Sending the request

Oajax.send ();

4. Receive return

Oajax.onreadystatechange=function ()
{
if (oajax.readystate==4)
{
if (oajax.status==200)
{
Alert (' success: ' +oajax.responsetext);
}
Else
{
Alert (' failure ');
}
}
};
};

which

Request Status Monitoring

onReadyStateChange Events

ReadyState Properties: Request Status

>0 (uninitialized) has not yet called the Open () method

>1 (load) called the Send () method, sending the request

>2 (loading complete) the Send () method completed, received all response content

>3 (parsing) parsing response content

>4 (completion) Response content resolution completed, you can invoke the Status property on the client: request result ResponseText

Status property: Request result

ResponseText

Talking about Ajax