Best way to execute a function on article view?

[Tim Landscheidt <tim@tim-landscheidt.de>]

Hi,

I have a function along the lines of:

| (gnus-with-article-buffer
|   (while (search-forward-regexp "^Alle Änderungen auf einen Blick:\n\\(https://de\\.wikipedia\\.org/w/index\\.php\\?title=.*&diff=0&oldid=[0-9]+\\)$" (point-max) t)
|     (browse-url (match-string 1)))
|   (gnus-summary-next-unread-article))

This searches the article for a URL and launches Firefox
(and moves to the next article).

Unfortunately this is somewhat orthogonal to my usual (most-
ly SPC-oriented) workflow for reading things.  I therefore
like to change my setup so that:

1. I select an article with SPC,
2. if the article contains such a URL, Gnus prompts me
   (y-or-n-p) if I want to browse that URL,
3. if I press SPC (which is "y" for y-or-n-p), the URL is
   browsed, and
4. if after that prompt I hit SPC again, the next unread ar-
   ticle is selected.

So in my "usual" workflow I wouldn't have to press anything
but SPC.

What is the best way to achieve that behaviour?  From a cur-
sory look at the manual, gnus-article-prepare-hook seems to
be the relevant hook.

Are there alternatives that are a better fit, for example a
washing function or something else?  One thing that would be
nice to have (additionally) is a similar behaviour to
gnus-summary-save-article (browse the URL in this article,
or in the next N, or in the previous - N, or in the articles
in the region, or in the marked articles (but in all but the
first case with no prompt)).

Tim