function hello()
{
var request = getXHR();
request.open("GET","A?value="+document.getElementById('a').value+"",true);
request.send(null);
request.onreadystatechange=function()
{
if(request.readyState==4)
{
if(request.status==200)
{
var val=request.responseText;
document.getElementById('a').value=val*10;
}
}
}
}
I found the above code..in an ajax tutorial...I cannot understand the reason for using
request.readyState==4
request.status==200
Can anyone explain me the reason for using this code segment?
The readystate basically means that the request has finished processing. 200 is the http status for OK. This means it is safe to try and access the data.
Really, use google!
Can anyone explain me the reason for using this code segment?
When a request to a server is sent, we want to perform some actions based on the response.
Refer State Description
0 The request is not initialized
1 The request has been set up
2 The request has been sent
3 The request is in process
4 The request is complete
In practice you almost never use any of them except for 4.
status
200: "OK"
404: Page not found
I hope.These will helps you.
When a request to a server is sent, we want to perform some actions based on the response.
The onreadystatechange event is triggered every time the readyState changes.
The readyState property holds the status of the XMLHttpRequest.
Three important properties of the XMLHttpRequest object
readyState: Holds the status of the XMLHttpRequest. Changes from 0 to 4:
0: request not initialized
1: server connection established
2: request received
3: processing request
4: request finished and response is ready
status
200: "OK"
404: Page not found