Building Custom Viz Plugins

This is a tutorial to help you build a "Hello World" viz plugin. The intent is to provide a basic scaffolding to build any sort of data visualization, using any viz libary you'd like (e.g. ECharts, AntV, HighCharts, VX, and D3.).

You can build the Hello World plugin by running a Yeoman generator, which takes a few simple options, and provides this plugin scaffolding.

Getting Set Up

Install Yeoman and the Superset Package Generator

This Hello World plugin we'll be building is generated automatically with Yeoman. Let's first get that installed by opening up a terminal and installing both the yo module and the superset package generator (v0.14.7) to create the new plugin.

npm install -g yo @superset-ui/generator-superset

Install Superset

There are complete instructions available on the Superset Github repository. In a nutshell, the easiest way is to:

Have a Mac or linux-based machine
Install Docker
Clone the repository to your computer
Use your terminal to cd into the superset directory
Run docker-compose up
Open another terminal, and cd into superset/superset-frontend
Run npm install to load up all the npm packages.
Run npm run dev-server to spin up the Webpack hot-reloading server
Wait for it to build, and then open your browser to http://localhost:9000 and log in with admin/admin. You're off to the races! (Note: we'll be restarting this later)

Install Superset-UI

Clone the superset-ui repository to your computer. It can sit in the same parent directory as your superset repo
Use your terminal to cd into superset-ui
Run yarn install and wait for all the packages to get installed

Build Your "Hello, World"

Write generate some code!

Using your terminal, cd into your local superset-ui repo folder and then into the plugins subdirectory.
Make a new directory for your plugin, i.e. mkdir plugin-chart-hello-world. Note: we highly recommend following the plugin-chart-your-plugin-name pattern.
Now cd plugin-chart-hello-world
Finally, run yo @superset-ui/superset
Select Create superset-ui chart plugin package on the following screen:

Give it a name (in our case, go with the default, based on the folder name):
Give it a description (again, default is fine!)
Choose which type of React component you want to make (Class, or Function component).
Select whether you'd like your visualization to be timeseries-based or not
Select whether or not you want to include badges at the top of your README file (really only needed if you intend to contribute your plugin to the superset-ui repo).
Admire all the files the generator has created for you. Note that EACH of these is chock full of comments about what they're for, and how best to use them.

Add your Plugin to Superset (with NPM Link)

Now, we want to see this thing actually RUN! To do that, we'll add your package to Superset and embrace the magic power of npm link to see it in-situ, without needing to build the plugin, or open any PRs on Github.

Add your package to the package.json file in superset/superset-frontend.

Note: Do not run npm install... explanation below.

Add your plugin to the MainPreset.js file (located in superset/superset-frontend/src/visualizations/presets/MainPreset.js) in two places, alongside the other plugins.

{' '}
Open a terminal window to superset/superset-frontend. If you did the Install Superset steps above, you may still have webpack running there, and you can just stop it with ctrol-c. If not, just open a new window and or cd to that directory path.

4) Use npm link to symlink plugin, using a relative path to superset-ui and your plugin folder, e.g. npm link ../../superset-ui/plugins/plugin-chart-hello-world.

Restart your webpack dev server with npm run dev-server. You'll know it worked if you see a line stating [Superset Plugin] Use symlink source for @superset-ui/plugin-chart-hello-world @ ^0.0.0.

NOTE: If/when you do an npm install that erases the symlink generated by npm link, so you'll have to redo those steps.

NOTE: Dynamic import is a work in progress. We hope you won't even need to DO this soon. We'll be blogging again when that day comes, we assure you. In short, we have a goal to make editing package.json and MainPreset.js unnecessary, so all the code changes are made in ONE repo.

See it with your own eyes!

You should now be able to go to the Explore view in your local Superset and add a new chart! You'll see your new plugin when you go to select your viz type.

Now you can load up some data, and you'll see it appear in the plugin!

The plugin also outputs three things to your browser's console:

formData, a.k.a. everything sent into your viz from the controls
props, as output from the transformProps file for your plugin's consumption
The actual HTML element, which your plugin has hooks into for any necessary DOM maniupluation

Make it Your Own

Now you're free to run wild with your new plugin! Here are a few places to start digging in:

Read the comments and docs

Take a look through the full file tree of the plugin. The Readme gives details for the job of each file. EACH of these files has been annotated with extensive comments of what the file is for, and the basics of what you can do with it.

Take control!

The plugin includes a couple of example controls, but you can certainly continue to add as many as you need to. The comments/documentation within the controls file is a start, but we recommend looking at existing superset-ui plugins for more examples of how you can implement controls to enhance your queries, work with your data, and change your visualization's display.

Build the perfect query

The buildQuery file where your plugin actually fetches data from the Superset backend. This file builds he query "context" for your plugin. For a simple plugin, this file needn't do much. There are a couple changes that need to be made for a timeseries plugin, thus the option in the Yeoman generator.

This file also allows you to add various post-processing operations, to have the Superset backend process your data in various ways (pivoting, etc), but that's a whole other topic we'll cover separately in the near future.

Style with Emotion

Each of these methods lets you add custom CSS styles using Emotion 👩‍🎤(a CSS-in-JS approach) which has access to Superset's burgeoning set of theme variables, and also automatically scopes the styles to your plugin, so they don't "leak" to other areas of Superset.

In the Hello World plugin, we've included a few example Theme variables (colors, gridUnits, and typographic weights/sizes). We'll be continuing to add more variables to this theme file as we continue to push Superset (and the viz plugins) toward the standards of the Superset redesign (see SIP-34)

Give it a thumbnail

Because come on... that's the fun part, right?

Build it!

In this tutorial, you built your plugin in the superset-ui repo. This means you can use the built-in build scripts that the repo provides. With your terminal of choice, simply cd into the root directory of supeset-ui and run yarn build. This will kick off a build of ALL the Superset plugins and packages, including yours.

Test early, test often!

The Hello World plugin includes some basic Jest tests to act as a starting point to add unit tests to your plugin. These do a quick sanity check that the plugin actually loads correctly, and then run through the basics of making sure that your controls are properly respected by modifying the resulting data and/or props of the plugin. Running yarn test from the root directory of superset-ui will run all the tests for plugins/packages, including your Hello World.

Deploying Custom Visualization to Production

To deploy plugins to a production environment, you must have additional code inside Superset that includes the npm packages of your plugins so they can be installed in the frontend.

One option is to build your Dockerfile so it contains your custom visualization packages.