html5 - Extending dart:html classes in dart -

i new dart , wonder if can, example, extend divelement class create custom elements in 1 line of code. looking this;

class redbox extends divelement {     redbox(text) {         this.text = text;         this.style.background = "red";     } }  redbox mybox = new redbox("hello world"); document.body.append(mybox); 

of course have more complex elements custom functions. in general, possible?

when try run this, get:

implicit call super constructor 'divelement()' 

you can extend html elements, there few requirements. 1 you're running need redbox.created constructor, , can redirect super class. created must generative constructor, though can add factory constructors.

another requirement element registered document.registerelement.

try adding this:

class redbox extends htmlelement {   redbox.created() : super.created() {     style.background = "red";   }   factory redbox(text) => new element.tag('my-redbox')..text = text; }  document.registerelement('my-redbox', redbox);