even though this is a bit old: You actually can pass parameters like this:
<my-custom-element booleanAttr valueAttr="test"></my-custom-element>
And your custom element should look something like:
@CustomTag('my-custom-element')
class MyCustomElement extends PolymerElement {
...
@published bool booleanAttr;
@published String valueAttr;
...
}
-- EDIT --
But as already pointed out this can be easily done for polymerelements with a factory:
import 'package:polymer/polymer.dart';
import 'dart:html';
@CustomTag('my-custom-element')
class MyCustomElement extends PolymerElement {
String a;
factory MyCustomElement.custom(String _a) {
MyCustomElemente = new Element.tag('my-custom-element');
e..a = _a
// ...
..initialized();
return e;
}
MyCustomElement.created() : super.created() {
}
void initialized() {
print("initialized: " + a);
}
}