getElementsByClassName returns [] instead of asynchronous appended node

Question

(I ask my question again after the first one was terribly formulated)

I face the following problem:

Answer 1

The above code is gray for a reason: it's a comment. Comments aren't parsed by the browser at all and have no influence on the page whatsoever.

You'll have to parse the HTML, read the comments, and make a new DOM object with the contents of the comment.