How to use Ajax to retrieve data from PHP file without jQuery

[KenBrace]

This is a basic tutorial on how to retrieve information from a php parser using Ajax without jQuery.

 

This is very useful when you wish to check if a user exists, check for live chat messages, etc.

 

Javascript

<script>

function send(){
var hr = new XMLHttpRequest(); //this variable represents your ajax request
var url = "parser.php"; //the url to your php parser
hr.open("POST", url, true); //initiate the ajax request
hr.setRequestHeader("Content-type", "application/x-www-form-urlencoded"); //set the request header
hr.onreadystatechange = function(){
if(hr.readyState == 4 && hr..status == 200){ //this code checks whether or not the request has fully processed and returned valid
var text = hr.responseText; //this is the text sent back from the php file
alert(text); //you can do whatever you wish with the response text
}
}
hr.send();
}

</script>

PHP (short example)

<?php

echo "this text will be retrieved using Ajax";

?>

Edited February 19, 2015 by Nathan

[Nathan]

Great thanks, added the code tags in there.

 

So what's the advantage of doing it this way?

[KenBrace]

Great thanks, added the code tags in there.

 

So what's the advantage of doing it this way?

 

There's not really a specific advantage of doing it this way vs using jQuery. It's the original way I learned it though so I tend to use it a lot since it's what I'm used to. It's also good just see exactly what's really going on when you use jQuery. A behind the scenes if you will. It's also good to know in case you don't have access to jQuery for some reason.