Xpath, In A Greasemonkey Script, Is Not Selecting Right Nodes On An Xhtml Page

I'm working on a Greasemonkey script for weibo.com. I can't pick the elements using XPath on the XHTML page. This code fails to grab the elements I want: function resolver(prefix)

Solution 1:

The problem is that the script is running before all of these nodes are added to the page. They are added by the page's AJAX later.

So, you could add a time-delay to your script. But:

1. If you just want to grab select elements, you almost never need to use XPath. Use querySelectorAll() or jQuery instead. Here's a basic example with querySelectorAll and no time delay:

   var allLinks = document.querySelectorAll ("a[action-type='login']");
   if (allLinks.length) {
       // PROCESS NODES AS DESIRED, HERE.
   }
   

2. Here's a complete Greasemonkey script, that handles the delayed content problem using jQuery and the waitForKeyElements() utility:

   // ==UserScript==// @name        _Weibo, hilite login links// @include     http://s.weibo.com/weibo/*// @require     http://ajax.googleapis.com/ajax/libs/jquery/1.7.2/jquery.min.js// @require     https://gist.github.com/raw/2625891/waitForKeyElements.js// @grant    GM_addStyle// ==/UserScript==/*- The @grant directive is needed to work around a design change
       introduced in GM 1.0.   It restores the sandbox.
   */functionprocessLoginLinks (jNode) {
       //***** YOUR CODE HERE *****
       jNode.css ("background", "lime");
   }
   
   waitForKeyElements ("a[action-type='login']", processLoginLinks);