Polymer 3使用behaivor的方式是什么？

Question

What's the proper way of using iron-overlay-behavior in Polymer 3. Shouldn't that be as simple as extending the class? But I ain't sure because my component already extends PolymerElement.

Any simple example should help.

Answer 1

Have you looked at the Polymer.mixinBehaviors() helper function? Behaviors are superseded by mixins as of Polymer 2, and as far as I can tell the version 3 does not bring any changes in that regard.

Here is how you would use iron-overlay-behavior in a Polymer 3 element:

import {PolymerElement} from '@polymer/polymer';
import {IronOverlayBehavior} from '@polymer/iron-overlay-behavior';
import {mixinBehaviors} from '@polymer/polymer/lib/legacy/class.js';

class MyOverlay extends
  mixinBehaviors([IronOverlayBehavior], PolymerElement) {
  ...
}

Answer 2

import {mixinBehaviors} from '@polymer/polymer/lib/legacy/class.js';

class MyClass extends mixinBehaviors([MyBehavior], PolymerElement) { ... }

from https://polymer-library.polymer-project.org/3.0/docs/devguide/registering-elements#using-legacy-behaviors-with-class-style-elements