method prepareElement

Source

void prepareElement() {
  if (_elementPrepared) {
    window.console.warn('Element already prepared: $_name');
    return;
  }
  _initJsObject();
  // Dart note: get the corresponding <polymer-element> declaration.
  _element = _getDeclaration(_name);
  // install property storage
  createPropertyObserver();
  openPropertyObserver();
  // install boilerplate attributes
  copyInstanceAttributes();
  // process input attributes
  takeAttributes();
  // add event listeners
  addHostListeners();
}