Ty,

I can't think of any really good ways to achieve what you are asking for.

The simple fact is that the template for a page has already been loaded by the time any modules are created -- the modules are defined by the template, so the template comes first.

Therefore the only way for a module to swap to a different template is for it to instigate a page redirect to a different URL, a URL that will use that different template.

That might be an approach to try -- setting up new menu items on a hidden menu that are very similar to the menu items on the main menu. But you then assign the 2nd template to each of these hidden menu items. Then you put a MetaMod onto your main menu items, with a rule in it that detects if the page is one that you want to view with your other template. If so, it does a redirect to the other URL.

But this is horrible for lots of reasons - it uses redirects, it would be quite slow, and I can imagine all sorts of messes where you are working out which part of the system a given page should be on. Yech.

I suppose ideally, this sort of decision making process should be at the level of the "Router" - the part of the system that looks at the outgoing URLs that are generated on the system and does any required re-writing (e.g. for SEF URLs), then looks at incoming SEF URLs and decides which  parameters they equate to.

Hmmm.... that opens up some technical possibilities, if it's possible to get into the router for incoming URLs. That way you might be able, technically, to detect certain conditions and dynamically change the Itemid as the requests come in... interesting possibility. But I have no idea if it's really possible or not. It's very advanced Joomla programming.

Sorry I can't be much more help. You're asking for work-arounds for deeply ingrained Joomla behaviour.

Cheers,
Stephen

Oh, this just gets better.

I found that you can make a system plugin that can override the template

Stay tuned for a plugin or component/plugin combination that should be able to do what you are asking for.

hmmm, it's going to take a little time... but I'll let you know when there's something available.

I don't know yet! Obviously it won't be exactly like MetaMod because it can't be a module. For ease of use it should be a component that communicates with a plugin, but it's quite a lot of work (meaning more chance I'll charge for it). No promises except that I'm going to work on it some more today.

I have a Beta version of this now ready - anyone want a copy? Please e-mail me and I'll send you one.

Cheers,
Stephen