"GL Style Package" specification

Best practice for storing complete "GL style" for a map in a GitHub repo, gist, directory or a zip package.

Map style preview

After following steps you will get free preview of your map on github.io pages like OSM Bright GL style preview.

Requirements

• GitHub repository
• Style saved as a style.json in root
• Icons used in style saved as SVG files inside icons/

Installation

Warning: Following steps will automatically create/rewrite content of you gh-pages branch on every push you make.

• Enable Travis for your repository
• Copy .travis.sample.yml into your repository master as .travis.yml
• Generate personal access token if you don't have any
• Encrypt it using travis encrypt -r [user]/[repo] GITHUB_TOKEN=[the token here] (install travis using gem install travis)
  • You can use also --add option when running this command to automatically append encrypted variable into your .travis.yml.
• Insert following to your .travis.yml (if it was not inserted using --add option):

env:
  global:
    - secure: [encrypted token here without quotes]

• Visit https://[user].github.io/[repo] in your browser.

Ideas

Discussion, specification and validator for correctness and completeness of storing map styles described in MapBox GL Style JSON together with all related assets in a single directory or github repository.

The spec should solve these issues:

• Storage of complete JSON GL styles in Github / Gist with revisions (versioning) and possible collaboration of multiple people / designers
• Specification of the structure of such repo, verifiable by a script
• Guarantee, that the style and all assets are included - and available in an editable form (sprites in SVG format, correctly linked fonts) - not in a derivative form, verifiable by a script
• Presence of license of the style (code+creative), part of verification
• It should be possible to deploy offline or deploy to a tileserver (TileServerGL or another)
• It should be possible to load & save the styles with an editor (Maputnik or another)
• Fonts may be saved in a separate repo - for easier reuse
• JSON style or another metadata file may contain information about compatibility requirements for the fonts, vectortiles, etc
• Ensure the style package (.zip made from GitHub repo) can be downloaded and used offline in a standalone mobile app

This repo should contain a script (to be run on Travis), which will validate the files with a set of tests, report potential issues and convert the original assets into an online preview hosted on gh-pages of the same github repo.

Related materials:

• Mapbox GL Style Spec: https://github.com/mapbox/mapbox-gl-style-spec & https://www.mapbox.com/mapbox-gl-style-spec/
• Process of compiling of assets described at: https://github.com/klokantech/osm2vectortiles-gl-styles

The spec/travis scripts may be applied on the default styles of OSM2VectorTiles, OpenMapTiles, KlokanTech, OSM Liberty, etc.