Thanks for the replies, everyone.
On Mon, Jun 19, 2017 at 8:42 PM, Bartosz Dziewoński <matma.rex(a)gmail.com> wrote:
I don't think "unloading" modules will
ever be a thing. While
ResourceLoader could be made to keep track of modules' CSS to be able to
remove it, we can't "unload" JavaScript modules at all (because their code
has already executed), so I'm not sure if we'd want to add such special
case.
I still think it'd make sense to have some sort of official support
for unloading modules' CSS, whether we're talking about CSS-only
modules or modules which happen to also include CSS. CSS and JS
obviously have different functions, and just like how you use
$out->addModules( 'some-module-name' ); to load JS modules and
$out->addModuleStyles( 'some-module-name' ); to load CSS modules in
PHP, why couldn't there be official support for unloading CSS modules?
Or failing that, support for a way to tell ResourceLoader, "yes, I
*really* want to reload this module again even if you think that it's
already loaded and thus there's no need to make another HTTP request".
If you want a slightly less horrible hack than you do
now – you could
generate an appropriate load.php URL yourself (with &only=styles) and add
that in a <link> tag to the page, much like we did back in the old days
with importStylesheetURI(). ResourceLoader won't even know the module is
loaded. And this way, you can remove the <link> tag later without messing
with ResourceLoader's internals.
Thanks for the suggestion. While I didn't
implement this at this time
-- simply because I managed to get my hacks working before you posted
this message -- I'm sure this is the route I'll have to take in the
future. For the time being, I solved the problem by using a cache
variable and caching loaded CSS there and instead of trying to
(unsuccessfully) call mw.loader.load() twice (or thrice etc.) I first
check cache and try to use the cached CSS if possible [1].
As always, code review of both the JS and PHP parts of the patchset
[2] is welcome, although the most acute problem (with the JS) is now
fixed and legoktm gave me a few good pointers on how to make the PHP
part saner. :-)
[1]
https://gerrit.wikimedia.org/r/#/c/359643/6..7/ext.theme.livepreview.js
[2]
https://gerrit.wikimedia.org/r/359643
Thanks and regards,
--
Jack Phoenix
MediaWiki developer