Method attachedCallback

src/base-element.js:450–452

* Override in subclass to adjust the element when it is being added to * the DOM. Could e.g. be used to add a listener. Notice, that this * callback is called immediately after `buildCallback()` if the element * is attached to the DOM.

()

   * is attached to the DOM.
   */
  attachedCallback() {
    // Subclasses may override.
  }

  /**
   * Override in subclass to adjust the element when it is being removed from