Jim's Depository

If you find yourself making ajax requests for HTML pages, then using jquery to massage them or extract data before displaying it, you should be aware that you may be attempting to load the <img> resources from the page. This can be a performance killer or information leak.

Consider…

function parseSomeDudesPage( pageText) {
    var page = $(pageText);   // <<<<------   This is the problem
    ... do a bunch of stuff with page...
}

...
   $.get('http://somedudeswebsite.com/blah/blah.html', parseSomeDudesPage);
...

That line marked as the problem will parse the text into DOM nodes which will be in your main document. The browser may decide to start fetching the images contained in pageText, (Safari 8.0.2 does). Depending how you fetched the document you could be getting images, broken links, or security domain violations for pulling http: resources into your https: page.

I think the solution is to keep the nodes out of your main document by creating a new one. Reading this stackoverflow comment and not caring about old browsers in my application I went with…

function parseSomeDudesPage( pageText) {
    var page = (new DOMParser).parseFromString( pageText, 'text/html');
    ... do a bunch of stuff with page which is a new document and doesn't trigger <img> loading.
}

Since you have a new document, you won’t be able to move nodes from page to your main document, but I tend to create nodes anyway, so I don’t miss the ability.