MkDocs Macros - Placeholders

This macros allows defining input parameters on a page, and automatically replace placeholders throughout the page.

How it works

1. Placeholders like %%database%% are used in Markdown wherever you want dynamic substitution.
2. The macro {{ placeholder("database") }} auto-generates that format.
3. The macro {{ create_input_block([...]) }} renders:
   • An input form for required/optional fields.
   • A JavaScript function that walks the entire rendered page and replaces all instances of %%<placeholder-id>%%.
4. When the user clicks "Apply" or presses Enter inside a field:
   • The entire page is scanned.
   • All matching placeholders (e.g. %%database%%) are replaced live.
   • Placeholders in other field values (like %%env%% inside %%database%%) are also resolved.

Using GET parameters for defaults

• If values are present in the URL, fields are pre-filled and automatically applied.

  http://localhost:8000/?database=mkdocsDb&env=test
  

Usage example

# Output Demo

{{ create_input_block([
  {"id": "env", "label": "Environment", "required": True, "default": ["dev", "prod", "test"]},
  {"id": "database", "label": "Database", "required": False, "default": "%%env%%_db"},
]) }}

\```html
<div style="color: green;">const database = "{{ placeholder("database") }}";</div>
<div style="color: green;">const env = "{{ placeholder("env") }}";</div>
\```

Run the demo

Build the container

docker build -t mkdocs-macros-placeholders .

Run the MkDocs server

docker run -p 127.0.0.1:8000:8000 --rm -v "${PWD}:/app" mkdocs-macros-placeholders