Re: document.write and innerHTML

[Adam Thompson <arthompson1990@gmail.com>]

On Fri, Jun 11, 2021 at 09:14:45PM -0700, Kevin Carhart wrote:
> Appends, so from the FF console if you send
> document.write(1);document.write(2);document.write(3)
> 
> document.body.innerHTML returns "123"
> 

As far as I can tell it's like a stream. When loading, the document is
opened for writing and thus document.write() appends. Once loading has
completed (when browsing) the document is closed. Thus, when
document.write() is called on an already closed document it first calls
document.open() which calls document.clear() (like using fopen with "w" as
the mode). Subsequent document.write() calls on the same document then find
the document is already opened and thus append. I'd need to check mdn again
but I'm not sure if there's also a document.close() call as well. All of
this sits below the DOM manipulation calls such that the DOM needs to be
adjusted after document-altering calls I think. I'm not sure how close this
is to what's currently implemented (especially after the last change) in
practical terms (e.g. if anyone widely uses document.open etc).

Cheers,
Adam.