TerriaJS sample plugin

This repository implements a sample TerriaJS plugin. The plugin implements a custom tool for drawing an interactive 3D box on the map. It serves as an example for setting up an loading an external plugin library that adds some new functionality to Terria without forking it.

Plugins allow extending Terria in two ways:

• By adding support for new data formats or APIs through implementing new catalog item types.
• and extending the UI in limited ways to create custom workflows.

This plugin code utilizes these additional peer dependencies from the TerriaJS library and are pre-requisites for understanding the code:

• terriajs-plugin-api - for interfacing with the TerriaJS library.
• CesiumJS - The 3D mapping library
• mobx - Reactive state management library
• ReactJS
• styled-components
• yarn - Package manager

Additional documentation for developing with terria is available at https://docs.terria.io. You can also reach us through our discussion forum if you require additional help.

This plugin repository is a work in progress and will be updated as the different APIs evolve. Meanwhile expect breaking changes 👷

Current status

• Load external plugins in TerriaJS at build time
• Support for registering custom data types (aka catalog items)
• Initial, limited support for extending UI to add custom workflows
• Testing
• Linting

Adding the plugin to your terriamap

Clone terriamap

git clone https://github.com/terriajs/terriamap
cd terriamap

Add this plugin as dependency in package.json

yarn add -W 'terriajs-plugin-sample'

Add it to the plugin registry file plugins.ts

const plugins: any[] = [
  import("terriajs-plugin-sample")
];
...
export default plugins;

Note: The file plugins.ts is in the terriamap project root directory.

Now build your terriamap and start the server

# From the terriamap directory run
yarn run gulp dev

Once the server is running visit http://localhost:3001 to load the app. You should see a new plugin button added to the map toolbar on the right hand side. Opening the tool will prompt the user to draw a rectangle on the map, this will place a 3d box of the same dimension on the map. Screenshot of the plugin in action:

Plugin development workflow

This section assumes you have completed the steps for adding the plugin to your terriamap.

Developing the plugin requires correctly setting up the yarn workspace. Your local directory structure should look something like:

terriamap/
  packages/
  ├── plugin-sample
  └── terriajs

The terriajs and plugin-sample repositories must be checked out under terriamap/packages/ folder

Checkout terriajs and sample-plugin into the packages folder

cd terriamap/
mkdir -p packages
git clone https://github.com/terriajs/terriajs packages/terriajs
git clone https://github.com/terriajs/plugin-sample packages/plugin-sample

Add the plugin package to the yarn workspace settings of your terriamap package.json file.

Edit package.json for terriamap:

  {
  "private": true,
  "workspaces": {
    "packages": [
      "packages/terriajs",
      "packages/cesium",
      "packages/terriajs-server"
      "packages/plugin-sample" // <-- plugin-sample added here
    ],

   ...
   
   "dependencies": {
    "terriajs-plugin-api": "0.0.1-alpha.16",
    "terriajs-plugin-sample": "0.0.1-alpha.8", // <-- plugin-sample version should match the version in packages/plugin-sample/package.json

Build terriamap

From your terriamap folder run:

yarn install
# Starts a terriamap dev server that watches for code changes and rebuilds the map
yarn run gulp dev

Build plugin-sample

cd terriamap/packages/plugin-sample
# Start a plugin build process that watches for file changes
yarn run watch

Note: you need to keep both the yarn commands running, then start making make changes to the plugin code, terriamap will automatically rebuild your changes.

Watch for errors from the plugin build process. Note that the app page doesn't reload automatically when the code rebuilds, you have to refresh the page to see your changes.