Showcase: Functions

Gravitron includes a series of handy functions like tags, categories, a page media gallery… And more is still to come. A demo for the sitemap-style listing of all existing pages is available here.

Per-page custom CSS

If enabled by setting css: in the page head and the specified CSS file exists in the folder of the page, the file is loaded automatically last in order: This way CSS overrides or extensions are possible per page, see the nicotine background gradient to the right bottom of this page:

css: "showcase-functions-custom.css"

Page aliases

Pages can have one or more alias URLs. The YAML page header of /showcase/theme has defined 3 alias URLs:

aliases:
    - "/demopage"
    - "/showcase/css"
    - "/css"

The page is reachable via /demopage, /showcase/css and /css. The canonical page is however SEO friendly set to the real URL, see the meta tag in its source:

<link rel="canonical" href="https://gravitron.dev/showcase/theme">

Be sure not to define identical alias URLs for more than one page or an alias with a primary URL of a page! While primary page URLs are processed first, multiple identical aliases may lead to unpredictable results. (The first match in pages order wins, but I won't tell you…)

Taxonomy

If present in the page, meta.tags and meta.categories are accessible:

Files

If enabled globally via ENABLE_PAGE_FILES, files in a page folder are propagated to the Twig array meta.files for file extensions listed in ALLOWED_PAGE_FILETYPES. Any custom page CSS file is ignored, see section "Per-page custom CSS" above:

• document.css: Type text/plain, size 0.06 kB Bytes, date: 2025-11-28, 06:23:57
• document.ini: Type text/plain, size 0.03 kB Bytes, date: 2025-11-17, 13:47:43
• document.pdf: Type application/pdf, size 186.00 kB Bytes, date: 2025-11-17, 13:50:44
• document.txt: Type text/plain, size 0.02 kB Bytes, date: 2025-11-17, 13:47:49
• gravitron.gif: Type image/gif, size 39.74 kB Bytes, date: 2025-11-18, 18:02:08
• gravitron.jpg: Type image/jpeg, size 72.61 kB Bytes, date: 2025-11-18, 18:01:52
• gravitron.svg: Type image/svg+xml, size 4.88 kB Bytes, date: 2025-11-25, 08:30:38
• gravitron.webp: Type image/webp, size 15.88 kB Bytes, date: 2025-11-18, 18:10:18

Media files

If enabled globally via ENABLE_PAGE_FILES, image and video files defined in ALLOWED_MEDIA_FILETYPES, are available in meta.media_files and can automatically be shown in an in-page gallery. — see below. Andre Rinas SimpleLightbox is used for image links with rel="lightbox". Any custom page CSS file is ignored, see section "Per-page custom CSS" above:

• gravitron.gif: Type image/gif, size 39.74 kB Bytes, date: 2025-11-18, 18:02:08
• gravitron.jpg: Type image/jpeg, size 72.61 kB Bytes, date: 2025-11-18, 18:01:52
• gravitron.svg: Type image/svg+xml, size 4.88 kB Bytes, date: 2025-11-25, 08:30:38
• gravitron.webp: Type image/webp, size 15.88 kB Bytes, date: 2025-11-18, 18:10:18

Gallery

Theme information

This theme has a user/config/theme.yaml file. If present and valid, its content together with configuration data is propagated to the Twig array theme:

• Variable theme_name: Gravitron
• Variable theme_author: Stefan Onderka
• Variable theme_email: contact@gravitron.dev
• Variable theme_website: https://gravitron.dev/manual/
• Variable theme_demo: https://gravitron.dev/
• Variable theme_repo: https://github.com/noppingen/Gravitron
• Variable theme_date: 2025-11-29 10:21:15 CET
• Variable theme_codename: Wanking Weasel
• Variable theme_version: 0.7 alpha

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