mdcms/docs/unreleased.md

Unreleased changes

Changes merged into development that have not yet been released to main.

---

Tabs & Accordions (app/index.html)

Four new mdcms fenced-block types for rich content layout. All four variants read from the active theme automatically — no new config keys, no per-theme overrides needed.

Block types

Language tag	Alias for	Renders as
tab-underline	—	Tab strip, active tab marked with underline
tab	tab-underline	(same)
tab-filled	—	Tab strip, tabs as filled chips
accordion-underline	—	Stacked accordion, header underline style
accordion	accordion-underline	(same)
accordion-filled	—	Stacked accordion, filled card style

Authoring syntax

Open a fenced block with the language tag mdcms <type>. The body is YAML with a single top-level key items:, whose value is a list of item objects.

```mdcms tab-underline
items:
  - title: Install
    default: selected
    content: |
      Install with `npm i mdcms` or `pnpm add mdcms`.
  - title: Configure
    content: |
      Drop a `mdcms.config.yaml` next to your content folder.
  - title: Deploy
    content: |
      Any static host. The build emits plain HTML.
```

Per-item keys

Key	Required	Type	Notes
title	yes	plain string	Label shown on the tab button or accordion header. Plain text only — no Markdown.
content	yes	Markdown block	Body content. Use the YAML literal block scalar (|) for multi-line Markdown. Rendered with the same pipeline as the surrounding page (GFM, syntax highlighting, internal links).
default	no	string	Tabs: selected marks the tab that is open on load; if no item has selected, the first item is used. notselected (or omitting the key) leaves the tab inactive. Exactly one tab should be selected. Accordions: open makes the item expanded on load; closed (or omitting) leaves it collapsed. Any number of accordion items may be open.
title-style	no	string	Heading level for screen readers and external TOC tools. One of "#", "##", "###", "####", "#####", "######", or "" (default). Visual size is always fixed by the component — this only changes the underlying ARIA role and level. Use a value when you want the item to be picked up as a heading by assistive technology.

Examples

Tabs — underline (default)

```mdcms tab
items:
  - title: npm
    default: selected
    content: |
      ```bash
      npm install mdcms
      ```
  - title: pnpm
    content: |
      ```bash
      pnpm add mdcms
      ```
  - title: yarn
    content: |
      ```bash
      yarn add mdcms
      ```
```

Tabs — filled chips

```mdcms tab-filled
items:
  - title: Overview
    default: selected
    content: |
      MD-CMS is a markdown-based static site system with no build step.
  - title: Features
    content: |
      - Sidebar navigation
      - Full-text search
      - PWA + offline support
      - Dark / light theme
```

Accordion — underline (default)

```mdcms accordion
items:
  - title: What is MD-CMS?
    default: open
    content: |
      A single-file browser renderer. No build pipeline, no compilation,
      no server required.
  - title: How do I install it?
    content: |
      Run `pip install mdcms` or download a binary from the GitHub releases page.
  - title: Does it work offline?
    content: |
      Yes — run `mdcms fetch-deps` to bundle vendor assets locally, then enable
      `pwa: yes` in `config.yml` for full offline support.
```

Accordion — filled cards

```mdcms accordion-filled
items:
  - title: Can I use custom themes?
    default: open
    content: |
      Yes. Create a `theme.yml` and reference it with `theme: theme.yml` in
      `config.yml`. The theme controls colours, fonts, and layout.
  - title: title-style example
    title-style: "##"
    content: |
      This header is announced as an `<h2>` to screen readers, even though
      its visual size is set by the accordion component.
```

How the appearance adapts to themes

The components derive their fill colours and bar/border colours from the active theme at runtime. No new keys in config.yml or theme.yml are needed.

Bold themes (nav background is visually distinct from the page — e.g. a dark sidebar on a light page, or a coloured nav like red or navy): filled tabs and accordion headers use the nav background colour as their fill; the bar/border uses the nav colour. This makes the components look like an extension of the sidebar chrome.

Subtle themes (nav background is almost identical to the page — e.g. both near-white or both near-dark): filled tabs use a light tint of the accent colour; the bar and border use the accent colour directly. This keeps the components visible without a strong nav background to borrow from.

The switch between bold and subtle is automatic. The algorithm uses HSL chroma (S × (1−|2L−1|)) rather than raw HSL saturation, which would give false "bold" readings for near-white or near-black nav backgrounds.

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mdcms build patches <title> with sitename

mdcms build now rewrites the <title> tag in index.html with the value of sitename from config.yml. Previously the tag was hardcoded (MD-CMS) in older templates, or blank in the starter template, so link previews in WhatsApp, Slack, and other crawlers that read static HTML showed the wrong name.

---

Untranslated posts now visible in all categories

Status: On development, pending release.

What was broken

When the category system is enabled, a post file without a category suffix (e.g. posts/my-post.md) was silently assigned to the default category only. Switching to any other category caused those posts to disappear from the nav and from posts-* tag listings — even though no translated version existed. If you wrote posts without a language suffix, they simply vanished the moment a visitor switched category.

Pages without a category suffix are unaffected: they continue to be assigned to the default category, which is the correct behaviour for pages.

What it does now

Posts without a category suffix are treated as uncategorised — meaning they appear in every category. A post called my-post.md now shows up regardless of which category is active. A post called my-post.en.md still appears only in the en category as before.

Mixed situations work as expected: if you have both my-post.md and my-post.nb.md, the Norwegian variant is shown when the nb category is active, and the bare my-post.md is shown for every other category.

What changes in the build output

After rebuilding a site with mdcms build, affected post entries in nav.yml gain an uncategorized: true field:

- file: posts/my-post.md
  title: My Post
  sort: 100
  uncategorized: true

In search.json, these entries carry "category": null instead of the default category code. This is what tells the renderer to include them universally.

A rebuild is required for existing sites to pick up the change.

---

Fix: category-variant pages fail to load on servers with SPA routing (e.g. Cloudflare Pages)

When a site uses category-suffixed page files (e.g. page.current.md) and is hosted on a server configured with SPA fallback routing (serving index.html with HTTP 200 for any unknown path), the renderer's fetchPageFile mistook the HTML fallback for a found markdown file. It returned index.html content instead of falling through to try the .current.md variant. The page rendered the raw HTML of index.html as markdown, showing the <title> text (sitename) in the content area.

fetchPageFile now checks the Content-Type response header and rejects any response with text/html, continuing to the next candidate URL instead.

---

Fix: stale service worker not removed when pwa: no

index.html unconditionally registers service-worker.js on every page load. When a site switched from pwa: yes to pwa: no, mdcms build stopped generating a new service worker, but the old one remained active in browsers that had visited the site before. The stale worker continued to serve cached responses from the old build.

mdcms build now writes a self-unregistering service-worker.js when pwa: no. On the visitor's next page load, the browser installs this stub worker, which immediately unregisters itself and evicts any previously cached content. manifest.json is also removed if present.

---

Fix: config.yml YAML parse errors now abort the build with a clear message

A malformed config.yml (e.g. a stray tab character, which YAML forbids as a token starter) previously caused read_config to silently return an empty dict. The build would proceed with no config — categories disabled, no default category code — producing a broken nav.yml with wrong filenames and missing variants fields, so category-variant pages would not appear in the sidebar.

read_config now raises ClickException on both OSError and yaml.YAMLError, aborting the build with a descriptive error message instead of continuing silently with an empty config.