ImageSlider

The ImageSlider extension provides a simple, dependency‑light before/after comparison slider for two images using a parser function.

It supports both vertical (left/right) and horizontal (up/down) reveal modes, is keyboard accessible (ARIA slider, arrow keys, Home/End), touch/mouse friendly, and adds no external libraries.

Based on the FürthWiki implementation by Mark Muzenhardt.

See the full documentation on mediawiki.org.

Development

The client-side code is written in TypeScript under src/. ResourceLoader serves plain JavaScript, so resources/js/imageslider.js is compiled output that is committed to the repository — edit src/imageslider.ts, never the generated file.

npm install
npm run build   # compile src/ -> resources/js/
npm run watch   # rebuild on save
npm test        # build, then run the jsdom test suite
npm run lint    # type-check src/ and tests/

docker compose up -d   # dev wiki on http://localhost:8080

See AGENTS.md for a fuller description of the layout and conventions.