Preview of theming does not work anymore

[MorrisJobke]

• change a value in the theming app
• wait for it to be saved
• then the "Loading preview" will show up
• actual: it loads endlessly and if you look at the network it will show you a 404 on css/core/server.css
• expected: the server.css is properly loaded and the loading spinner goes away

Problem: The server.css is in my instance for example served under css/core/72408cbdff8901cd16b886aeabcc367c-server.css - I guess the reloadStylesheets() method needs an adjustment to fetch the current name of this an reload that css.

server/apps/theming/js/settings-admin.js

Lines 44 to 65 in 3470d0a

	var reloadStylesheets = function(cssFile) {
	var queryString = '?reload=' + new Date().getTime();
	var url = OC.generateUrl(cssFile) + queryString;
	var old = $('link[href*="' + cssFile.replace("/","\/") + '"]');
	var stylesheet = $("<link/>", {
	rel: "stylesheet",
	type: "text/css",
	href: url
	});
	stylesheet.load(function () {
	$(old).remove();
	stylesheetsLoaded--;
	if(stylesheetsLoaded === 0) {
	$('#theming_settings_loading').hide();
	var response = { status: 'success', data: {message: t('theming', 'Saved')}};
	OC.msg.finishedSaving('#theming_settings_msg', response);
	}
	});
	stylesheet.appendTo("head");
	};
	reloadStylesheets('/css/core/server.css');

cc @danxuliu @juliushaertl @nextcloud/theming

Valid for at least master.

[danxuliu]

I was already working on fixing this ;-)

[juliusknorr]

Also broken on 12.0.1 RC4 🙈

[MorrisJobke]

Fix is in #5981

[fduraibi]

I think I have the same issue and it is cause by caching.

When I disable caching it works fine.
Is there a way to force reloading the new files into the cache whenever there is a theme change?

[nursoda]

Seems I'm hit by this in NC17, too. Standard setup of nginx/mariadb/apcu/redis on Arch.

I get 404 for https://test.seyfarth.de/apps/theming/styles?reload=1570557643276.
FX_DevConsoleNetwork says "cache-control: no-cache, no-store, must-revalidate".

@fduraibi What do you mean by disabling cache? Redis? Not an option except for debugging :-)

Edit: Just noticed that it works fine in Chrome, and that I have plenty of CSP blocked URIs in Firefox. If anyone has a hint on where to debug THAT (but that's off-topic, sorry).

During my tests I also encountered that the page is missing css altogehter, I then see these error messages:

Refused to apply style from 'https://cloud.domain.com/css/core/68b4-bd84-results.css?v=1f648e556779fb4921ea9f25d235efb0-93b5eae9-31' because its MIME type ('text/html') is not a supported stylesheet MIME type, and strict MIME checking is enabled.