Answer by hsivonen for Appending HTML string to the DOM

The right way is using insertAdjacentHTML. In Firefox earlier than 8, you can fall back to using Range.createContextualFragment if your str contains no script tags.

If your str contains script tags, you need to remove script elements from the fragment returned by createContextualFragment before inserting the fragment. Otherwise, the scripts will run. (insertAdjacentHTML marks scripts unexecutable.)