octfx/template-styles-extender

Extends TemplateStyles with new CSS properties

v3.0.0 2026-08-24 21:50 UTC

Requires

• composer/installers: >=1.0.1

Requires (Dev)

• mediawiki/mediawiki-codesniffer: 52.0.1
• mediawiki/mediawiki-phan-config: 0.20.0
• mediawiki/minus-x: 2.0.1
• php-parallel-lint/php-console-highlighter: 1.0.0
• php-parallel-lint/php-parallel-lint: 1.4.0

GPL-2.0-or-later

• Hannes Kruse
• alistair3149

• extension
• mediawiki
• TemplateStyles
• TemplateStylesExtender

Published on Packagist.org on 2026-08-24 21:50 UTC

README

Widens the CSS that Extension:TemplateStyles accepts on a wiki.

Writing CSS on a wiki that has this installed? See docs/css-support.md for what you can now write.

Requirements

• MediaWiki 1.43.9 or later
• Extension:TemplateStyles

Installation

Download the zip file from the latest release page.

Extract the folder to extensions/TemplateStylesExtender, then add to LocalSettings.php:

wfLoadExtension( 'TemplateStyles' );
wfLoadExtension( 'TemplateStylesExtender' );

The order matters. Both extensions register a handler for the <templatestyles> tag and the later registration replaces the earlier one, so loading this one first leaves wrapclass with no effect and no error.

Configuration

Scoping and URL policy are unchanged by default: every selector is still scoped to .mw-parser-output, and url() is still checked against $wgTemplateStylesAllowedUrls. Two settings below opt out of one each.

Configuration	Description	Default
$wgTemplateStylesExtenderCustomPropertiesDeclaration	Allow CSS custom properties (--*) to be declared.	true
$wgTemplateStylesExtenderExtendCustomPropertiesValues	Allow var() in properties whose own grammar has no slot for it.	true
$wgTemplateStylesExtenderRequireFontFamilyPrefix	Require @font-face family names to start with TemplateStyles. TemplateStyles enforces this itself; installing this extension lifts it until you set this to true. @font-face is not scoped to .mw-parser-output, so a family declared on a TemplateStyles page applies to the whole rendered page, including skin chrome.	false
$wgTemplateStylesExtenderAllowExternalResourcesInCustomProperties	Allow url(), image-set() and the other external-resource functions inside custom property (--*) values. Those URLs are then no longer checked against $wgTemplateStylesAllowedUrls; enable it only where an enforced Content-Security-Policy restricts these fetches to trusted hosts.	false
$wgTemplateStylesExtenderEnableUnscopingSupport	Allow CSS to be unscoped by setting a wrapclass attribute.	false
$wgTemplateStylesExtenderUnscopingPermission	The right a user must hold to unscope CSS. Must name a right that already exists on the wiki; this extension defines none.	editinterface

$wgTemplateStylesDisallowedProperties and $wgTemplateStylesDisallowedAtRules still apply, including to the properties this extension adds, so either list can narrow the grammar back per property or per at-rule.

Nothing here narrows it wholesale; removing the extension is that lever. It needs no database change, and neither does turning a setting off: pages already rendered keep their CSS until they are re-parsed, and a stylesheet page that used the widened CSS still renders with the refused rules dropped. It cannot be saved again until they are removed.

Unscoping with wrapclass

With $wgTemplateStylesExtenderEnableUnscopingSupport on, a wrapclass attribute scopes the stylesheet to a class of your choosing instead of .mw-parser-output:

<templatestyles src="Foo/style.css" wrapclass="mediawiki" />

Three things to weigh before enabling it:

• The right reaches the whole page. Any class is accepted, so wrapclass="mediawiki" scopes a rule to the body class and it can restyle anything on the page. Grant the right as you would the right to edit site CSS.
• It effectively limits editing to holders of that right. Anyone without it who edits the page replaces the unscoped CSS with an error message visible to every reader, on top of the normally scoped CSS. Putting the tag in a template rather than an article moves the check to the template's last editor.
• It is potentially expensive. Each wrapclass tag costs a lookup of the last editor of the page the tag sits on, plus a rights check.

Contributing

Issues and pull requests go to the repository.

License

GPL-2.0-or-later. See COPYING.