Today, I wanted to dynamically create some content via an html canvas in my angular.dart application. After some tinkering, I figured out how.
First, you need to mix in the NgShadowRootAware class which will give you a onShadowRoot method. In this method, you can get a reference to your Canvas element that's created in the component's html. I save a reference to the context2D there.
Then, you can use the context2D to draw your view whenever content gets updated. For instance, I have the drawTimeline() call in the setter for the current day property.