Hello all,
I wonder how can I find a specific text in the source of a web page.
I know I can find DOM elements with JavaScript, with statements like that
"color = document.body.style.background"
but I need to find text that is not part of the DOM Objects.

I know JavaScript has some functions to search in the page, but I need to search in the source page, not in the rendered html page.

To be more specific, when I check news on a specific website like this: http://www.bbc.co.uk/news/technology-16382648
I need to make a script (a bookmarklet or a greasemonkey script) to extract the date, and therefore I have to search for the text "<span class="date">"

In other words: how can I make a script or a Firefox addon to "grep" for a certain text on a web site?

I am using Firefox browser, so for me it's enough a solution that only works in that browser.