title: How to process a page loaded with XMLHttpRequest with Php
body: <p>I want to build a site that will extract information from pages relevant to the user. Simplified view is that user select "cat", I then use XMLHttpRequest to load the content of relevant pages. I would like this content to be processed by PHP (server side). Is it possible to do? </p>
  
  <p>Step by step:</p>
  
  <ol>
  <li>User enter an interest</li>
  <li>Ajax fetch pages content (using the client's user agent) matching the interest</li>
  <li>Fetched pages are process by PHP (for data extraction)</li>
  <li>Result of #3 is displayed to the user </li>
  </ol>
  
  <p>Thanks!</p>