Instead of making a new Polymer component from scratch, as we did in the previous recipes, you can also start from a native HTML element and build upon that. This is made possible because our component is backed up by a class that can inherit the properties and behavior of an existing HTML element class. For our example, we will extend a
Div element. You can find the code in the project
web\index.html, where a component with the name
dom-extendis imported through the following line:
From this, we know that the component is defined in
dom_extend.html, and the code behind it is in a file named
dom_extend.dart. For a discussion of the ...