Is there a way to allow mutually exclusive selection of a Gadget? Just like one cannot use two skins at once, neither should they use to skin-theme Gadgets at once.
I have my theme Gadgets associated under a "Skin Theme" section on Special:Preferences#mw-prefsection-gadgets page, so there should be a way to give them radio-button like behavior I would think.
I'd be happy to be proven wrong, but I don't think there's any built-in functionality to do something like that. I think you'd have to create a selector gadget whose responsibility is allowing your users to select a skin theme; the downside here is that now you've got to store their selection yourself. If it's a registered-accounts-only thing (as I'm guessing from the description you wrote), you can have the gadget create a page in the user's userspace with their setting (a .js or .json page would be best for this, since non-admin users cannot edit one of these pages outside their own userspace); if not, you'd have to set a cookie or use LocalStorage or something else browser-side.
Yes, my users are registered via a linked forum account, so it's a closed wiki. It doesn't hurt to have three skin theme gadgets. They override each other completely, with the lowest on the list having priority, but they can select all three at the same time, which seems clunky.
I thought there may be built-in functionality to allow mutually exclusive selection.
Note that the "selector gadget" can't run on Special:Preferences (no site/user script/gadget code runs there at all, for security purposes), so users would still be able to select multiple such gadgets at once from that place, sadly.
The point to suggesting a "selector gadget" was that it would take the place of the individual theme gadgets: instead of choosing a theme via Special:Preferences, editors would instead choose it via the selector gadget, and the themes themselves would no longer be listed on Special:Preferences. (I realize I forgot to actually say this before, though.)
Since the theme gadgets are designed such that they aren't conflicting if multiple are enabled, and alternatives to prevent this would involve extra balls to juggle for the gadget author/maintainer (and probably also flashes of unthemed content, before the theme has been able to load and be applied on the current pageview), it's probably better to just accept the current state of things - if Gadgets 2.0 is any indication, we're not likely to see improvements to the gadgets system for a long time.
Yeah, I was thinking the same thing. It works fine but is just not tidy. I can see users complaining that their theme selections aren't working without realizing that they left multiple selected
... on another note, this all could be complicated by the supposed planned move from Mediawiki to Gadgets namespace for loading resources. See: my post over there. Basically, a lot of wikis' css/js could be broken if not done with care.
I can see users complaining that their theme selections aren't working without realizing that they left multiple selected
It sounds like each gadget can already detect when more than one is enabled; if that's right, then it should be pretty straightforward to have them display a warning if the user enables more than one of them.
Small comment: nowadays, you can store user selection without resorting to a page in their userspace. The "options" api allows you to save user defined (or gadget defined) options, asking only that the option name starts with "user-". Retrival of option value does not require an api call, and mw.user.options.get() works like for any other option. Peace.
