**[ This description is mirrored from README.md at [github.com/arsnebula/nebula-checked-behavior](https://github.com//arsnebula/nebula-checked-behavior/blob/v2.0.0/README.md) on 2019-05-22 ]** [](https://www.webcomponents.org/element/arsnebula/nebula-checked-behavior) [](https://www.polymer-project.org) [](https://saucelabs.com/beta/builds/1c182290c7a24faa8cf2c97b8b86be2d) [](https://gitter.im/arsnebula/webcomponents) [](https://www.patreon.com/arsnebula) # \ A [Polymer](https://www.polymer-project.org) ES2015 class extension mixin to support a checked state. * Adds a `checked` and `value` property to a custom element * Processes keyboard, mouse and touch gestures to update `checked` state and trigger standard events * Supports [WAI-ARIA](https://www.w3.org/TR/wai-aria-practices-1.1/#checkbox) authoring practices for **a11y** ## Installation ``` $ bower install -S arsnebula/nebula-checked-behavior ``` ## Getting Started Import the package. ```html ``` Use the class mixin factory to extend an element. ```js class DemoElement extends Nebula.CheckedBehavior(Polymer.Element) { static get is() { return 'demo-element' } } customElements.define(DemoElement.is, DemoElement) ``` Style the element based on the `checked` attribute. ```css :host([checked]) { background-color: green; } ``` *For more information see the API Reference documentation.* ## Contributing We welcome and appreciate feedback from the community. Here are a few ways that you can show your appreciation for this package: * Give us a **Star on GitHub** from either [webcomponents.org](https://www.webcomponents.org/element/arsnebula/nebula-element-mixin) or directly on [GitHub](https://github.com/arsnebula/nebula-element-mixin). * Submit a feature request, or a defect report on the [Issues List](https://www.webcomponents.org/element/arsnebula/nebula-element-mixin/issues). * Become a [Patreon](https://www.patreon.com/arsnebula). It takes a lot of time and effort to develop, document, test and support the elements in our [Nebula Essentials](https://www.webcomponents.org/collection/arsnebula/nebula-essentials) collection. Your financial contribution will help ensure that our entire collection continues to grow and improve. If you are a developer, and are interested in making a code contribution, consider opening an issue first to describe the change, and discuss with the core repository maintainers. Once you are ready, prepare a pull request: 1. Fork it! 2. Create your feature branch: `git checkout -b my-new-feature` 3. Commit your changes: `git commit -am 'Add some feature'` 4. Push to the branch: `git push origin my-new-feature` 5. Submit a pull request :D ## Change Log See [CHANGELOG](/CHANGELOG.md) ## License See [LICENSE](/LICENSE.md)