See the component page for more information.
We've put together a guide to world-data to help get you rolling.
Add the logic specific to your new element and verify its functionality. Good unit tests are essential to your verification plan but a good way to quickly sanity test your component is to access your demo.html file via a local web server. There are several ways to do this but one easy method is to run a simple web server that ships with Python, using the commands:
python -m SimpleHTTPServerOr other method using NodeJS:
http-server ./This starts a web server on port 8000, so you can test your new element by navigating a browser to localhost:8000/test/index.html.
The tests are also compatible with web-component-tester. You can run them on multiple local browsers via:
npm install -g web-component-tester
wct