Get response from server with Javascript after Javascript request

Question

My Javascript function request to a aspx page. İts Code:

 var xhr = ("XMLHttpRequest" in window) ? new XMLHttpRequest() : new ActiveXObject("Msxml3.XMLHTTP");
    xhr.open("GET", = 'http://www.example.net/abc.aspx', true);
    xhr.send(""); 

After this request I want to send a response back from this page and catch it on the client side. How do I do that?

Answer 1

To get the response from XMLHttpRequest in asynchronous mode (third parameter is true for the open() method) you have to set the onreadystatechange property to a callback function. This function will be called back when the response is ready at the browser:

xhr.open("GET", 'http://www.example.net/abc.aspx', true);
xhr.onreadystatechange = function() {
  if (xhr.readyState === 4)  { 
    var serverResponse = xhr.responseText;
  }
};
xhr.send(null);

You may want to check out the following article for further reading on the topic:

• AJAX Patterns: XMLHttpRequest Call