Markdown Fences
The Markdown transformer replaces Mermaid fences in an output tree, leaving the source files untouched.
What gets transformed§
A fenced code block tagged mermaid is replaced with inline SVG:
```mermaid
flowchart LR
A --> B
```The generated Markdown contains:
<div class="mermaid-diagram">
<svg ...>...</svg>
</div>The transformer handles backtick and tilde fences, indented fences, and multiple diagrams in one file. Fences in other languages are left untouched. An unclosed fence is also left unchanged.
Source files stay untouched§
Use --out-dir to write the transformed Markdown into a separate tree:
ondine markdown content --out-dir build/contentDirectory inputs mirror their relative paths under the output directory. For example, content/posts/example.md becomes build/content/posts/example.md.
The command writes Markdown only. Copy non-Markdown files from the source tree separately if your site needs colocated assets.
Check generated output§
ondine markdown content --out-dir build/content --check--check writes nothing. It exits with status 1 when a generated file is missing or stale, which makes it suitable for CI. The output directory must already exist.
Write one file to stdout§
ondine markdown page.md --stdout--stdout accepts exactly one Markdown file and writes the transformed Markdown to standard output.
IDs and accessibility§
Ondine emits fixed ondine-title and ondine-desc IDs when the diagram source defines an accessibility title or description. The transformer namespaces those IDs per diagram, so multiple diagrams can share one page without collisions.
Use Mermaid's accTitle and accDescr directives in the fence:
```mermaid
flowchart LR
accTitle: Build pipeline
accDescr: Source is compiled to inline SVG.
A --> B
```There is no separate alt or caption metadata syntax. The fence source and the generated SVG carry the accessible information.
Static site example§
A typical static-site pipeline is:
ondine markdown content --out-dir build/contentBuild the site from build/content, or use the same directory as the content root of your generator. Keep the original content tree as the source of truth.