Make an AJAX call for an event in php

Question

I do not know if my tile line is enough ... My problem: I have a JS application that should wait for events on the server. At the moment, it checks continuous server data through XMLHttpRequest every second.

I’m thinking about: is it possible to make a call wait until, for example, a variable in PHP changes?

Hope my question is clear enough.

Thanks!

Answer 1

You are looking for a lengthy survey (usually called Comet). There are many examples in SO and elsewhere.

• http://blog.perplexedlabs.com/2009/05/04/php-jquery-ajax-javascript-long-polling/
• How to implement the basic "long survey"?
• http://www.contentwithstyle.co.uk/content/long-polling-example-with-nodejs
• http://www.zeitoun.net/articles/comet_and_php/start