What is needed is as follows:
I have an HTML webpage and I need to access another website and get something from its source code.
I want to run something like
link = "http://www.google.com"; doc.querySelectorAll('#courses_menu > ul > li > a'); // Apply on the link.
to get what I need from the link and use it!
However, I am using Jetpack slide bar.
Does it have to do anything with HTTP requests?
I think you could pull the entire page using an Ajax request, put the content in a hidden iframe, and then manipulate the DOM in the iframe. Something like (here using the jQuery framework)