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JavaScript

akash dikkaram
akash dikkaram
1,927 Points
Posted by akash dikkaram
akash dikkaram
1,927 Points

Can SomeOne Explain The Code Flow In Order ?

Can SomeOne Explain The Code Flow In Order ?

    var a= new XMLHttpRequest();
    a.onreadystatechange=function()
    {
    if(a.readyState===4)
     {
        document.getElementById('ajax').innerHTML=a.responseText;
     }
     };
     a.open('GET','sidebar.html');
     function senda(){
      a.send();
      }

1 Answer

Farid Wilhelm Zimmermann
Farid Wilhelm Zimmermann
16,753 Points
Farid Wilhelm Zimmermann
Farid Wilhelm Zimmermann
16,753 Points

Step 1: declare a new XHR object

var xhr = new XMLHttpRequest();

Step 2: setting a callback function

    //onreadystatechange is an event listener that gets trigered once the xhr(a) changes its state //

xhr.onreadystatechange = function() {

//if xhr state is equal to 4 (4 means it got its response back)//

if (xhr.readyState = 4) {

//updates div id=ajax with the xhr responseText//

document.getElementById('ajax').innerHTML=a.responseText;
 }
 };

Step 3: Open a Request

xhr.open('GET', 'sidebar.html");

Step 4: Send Request

xhr.send();

I used the variable xhr instead of a, but the context remains the same.

Further Explaination for .readyState property

īģŋ.readyState holds the status of the XMLHttpRequest:

0: request not initialized 1: server connection established 2: request received 3: processing request 4: request finished and response is ready

Happy Coding :)