MapLibre GL JS Documentation

The source code for https://maplibre.org/maplibre-gl-js-docs/, the website that hosts API documentation and examples for MapLibre GL JS. A GitHub Actions Workflow is triggered on push to the main branch. This Action builds the static website and deploys it to GitHub Pages by pushing to the gh-pages branch.

Migration Note

We are now migrating this documentation from Mapbox to MapLibre. If you want to contribute feel free to open an issue on GitHub or submit a pull request to propose directly your changes.

Requirements

• Node 16
• npm 8

If you're not sure if your Node and NPM versions are up to date, run nvm use before installing dependencies. If you don't have NVM installed, you can find installation instructions here.

The NPM scripts will not run on Windows, but work perfectly with WSL2.

Setting up the Development Environment

After cloning this repository, run:

npm ci # install dependencies with npm
git submodule update --init # initialize maplibre-gl-js git submodule
cd maplibre-gl-js && npm ci && npm run build-tsc

When pulling in new commits that change the maplibre-gl-js submodule, run git submodule update to update the local copy as well.

Writing API Documentation

API documentation is written as JSDoc comments and processed with documentationjs in the source code of maplibre-gl-js. This repository fetches the source code through a git submodule.

• Classes, methods, events, and anything else in the public interface must be documented with JSDoc comments. Everything outside of the public interface may be documented and must be tagged as @private.
• Text within JSDoc comments may use markdown formatting. Code identifiers must be surrounded by `backticks`.
• Documentation must be written in grammatically correct sentences ending with periods.
• Documentation must specify measurement units when applicable.
• Documentation descriptions must contain more information than what is obvious from the identifier and JSDoc metadata.
• Class descriptions should describe what the class is, or what its instances are. They do not document the constructor, but the class. They should begin with either a complete sentence or a phrase that would complete a sentence beginning with "A T is..." or "The T class is..." Examples: "Lists are ordered indexed dense collections." "A class used for asynchronous computations."
• Function descriptions should begin with a third person singular present tense verb, as if completing a sentence beginning with "This function..." If the primary purpose of the function is to return a value, the description should begin with "Returns..." Examples: "Returns the layer with the specified id." "Sets the map's center point."
• @param, @property, and @returns descriptions should be capitalized and end with a period. They should begin as if completing a sentence beginning with "This is..." or "This..."
• Functions that do not return a value (return undefined), should not have a @returns annotation.
• Member descriptions should document what a member represents or gets and sets. They should also indicate whether the member is read-only.
• Event descriptions should begin with "Fired when..." and so should describe when the event fires. Event entries should clearly document any data passed to the handler, with a link to MDN documentation of native Event objects when applicable.

Writing Examples

Examples are written as Batfish pages in docs/pages/example. Each example requires two files: an .html file containing the source code for the example, and a .js file containing example boilerplate and front matter. The front matter should include the following items:

• title: A short title for the example in sentence case as a verb phrase.
• description: A one sentence description of the example in plain text. This description will appear alongside a thumbnail and title on the examples page.
• topics: An array of topics for the example, see docs/data/topics.json for a list of topics.
• thumbnail: The filename of the example's thumbnail image (without the file extension).
• contentType: example: Set the contentType to equal example.

In content area of the markdown page include an extended description of the example and add links to documentation or other important resources where possible.

In the .html file, write the HTML and JavaScript constituting the example.

• Do not include an access token in the example code. The access token will be inserted automatically by the template, using the current logged in user's default public token, or a placeholder <insert token here> string if the user is not logged in.
• On commit, Prettier will format the code for all files, including HTML.

Every example must have an accompanying image. To get an image, run the site locally and take a screenshot of the rendered map in the example:

1. Run npm run create-image <example-file-name> <mapbox-access-token>. The script will take a screenshot of the map in the example and save it to docs/img/src/. Commit the image.
2. Run npm start to verify that your example image is loading as expected.

💡 If npm run create-image does not generate an ideal image. You can also take a screenshot of it yourself by running the site locally with npm start and taking a screenshot of the example map in PNG format. Resize it to 1200 x 500 pixels and save it in the docs/img/src folder.

Running the Documentation Server Locally

To start a documentation server locally, run:

npm start

The command will print the URL you can use to view the documentation.

💡 If you receive an error related to @mapbox/appropriate-images, try nvm use && npm start.

The examples section of the locally run documentation will use the GL JS version located in ../maplibre-gl-js/dist, so make sure to have a working minified build in your local copy of the maplibre-gl-js repo (not the submodule; clone maplibre-gl-js into the same directory as maplibre-gl-js-docs and run npm build-prod-min there).

Committing and Publishing Documentation

When a new GL JS release goes out, the release manager will make a PR that updates this repo's maplibre-gl-js submodule to point to the new release. When updating the submodule, you may need to run npm test -- -u to update Jest snapshots related to the sidebar navigation.

To update or add a new example, PR the relevant changes to this repo. The example will be live once the PR is merged. If this example uses a version of GL JS that isn't yet released, the PR should not be merged until the release is out.