Meta Resources
explains how metadata is used in a Decker deck. Each slide focuses on a specific metadata concept
September 22, 2025
Samantha Monty
Chair for Human-Computer Interaction, University of Würzburg

Introduction to Metadata in Decker

Title: What is Metadata in Decker?

Content:

  • Metadata is data that describes other data.
  • In Decker, it is used to customize slides and resources.
  • It includes things like colors, file paths, reveal.js settings, and more.

The metadata is used for this deck

---
color:
  black: "#000"
  magenta: "#f0f"
  white: "#fff"
csl: /test/decks/acm-sig-proceedings.csl
deep:
  down:
    bool: true
meta-data:
  - chart-meta.yaml
  - level1.yaml
rpv-test:
  branch:
    no-path: just some value
    path: /test/decks/data/just-used-in-template.png
  deeper:
    leaf-path: /test/decks/data/just-used-in-template.png
  leaf-no-path: just some value
  leaf-path: /test/decks/data/just-used-in-template.png
runtime-path-variables:
  - one.more.from.doc.meta
something: /test/decks/include/06-metal.png
static-resource-dirs:
  - assets
template:
  css: dummy.css
test:
  default-decker-deck: From this deck
  merge-list:
    - This line is from this deck
  some-value: This line is from this deck
title: Meta Resources 
subtitle: explains how **metadata** is used in a Decker deck. Each slide focuses on a specific metadata concept
whiteboard-background-color: "#f0f"
---

Using External Metadata Files (meta-data)

Title: Importing Metadata from YAML Files

Content: - Use the meta-data key to include external YAML files.

  • Example:x

    meta-data:
  - chart-meta.yaml
  - level1.yaml

  • These files define reusable values for the deck.

Referencing Metadata in Slides ([:meta](...))

Title: Displaying Metadata Values Inside Slides

Content:

  • Use [:meta](key.path) to show metadata values.

  • Example:

    [:meta](color.white) → white color
    [:meta](test.default-decker) → value from decker.yaml

Metadata Source Precedence

Title: Metadata Loading Order

Content:

  1. Current deck (in the markdown file)
  2. decker.yaml
  3. default.yaml
  • Higher-priority sources override the lower ones.

Merging List Values

Title: Combining Lists from Multiple Sources

Content:

  • Lists with the same key are merged from various sources.

  • Example:

    The test.merge-list includes values from default.yaml, decker.yaml, and the current deck.

File Path Metadata (runtime-path-variables)

Title: Variables that Hold File Paths

Content:

  • Stores file paths such as images or data files.

  • Example:

    rpv-test:
  leaf-path: /path/to/image.png

  • Useful for loading assets in the deck.

Color Values in Metadata

Title: Defining and Using Colors

Content:

  • Define color values in metadata:

    color:
  white: "#fff"
  black: "#000"
  magenta: "#f0f"

  • Use them in slides:
    [:meta](color.magenta)

Reveal.js Configuration via Metadata

Title: Reveal Settings Like Centering, Slide Numbers

Content:

  • Reveal.js uses metadata to control presentation behavior.

  • Examples:

    • reveal.center: center slide content
    • reveal.slideNumber: show slide numbers
    • reveal.history, reveal.fragments

Transitive Inclusion Chain

Title: Following Metadata Inclusion Chains

Content:

  • Metadata files can include others, forming a chain.

  • Example:

    meta-resources-deck.md <- level1.yaml <- include/level2.yaml <- 06-metal-v.png

Static Resource Paths

Title: Declaring Static Files and Paths

Content:

  • Static resources are declared using static-resource-dirs.
  • Metadata may also include absolute file paths for resources like images.

Conclusion

Title: Why Use Metadata?

Content:

  • Better control, structure, and reusability.
  • Easy to adjust global settings without editing all slides.
  • Clean separation of data and presentation logic.