**[ This description is mirrored from README.md at [github.com/arsnebula/nebula-dispatch](https://github.com//arsnebula/nebula-dispatch/blob/v2.0.3/README.md) on 2019-05-22 ]** [](https://www.webcomponents.org/element/arsnebula/nebula-dispatch) [](https://www.polymer-project.org) [](https://saucelabs.com/beta/builds/c5332849634f47c0ab51948a8326b79e) [](https://gitter.im/arsnebula/webcomponents) [](https://www.patreon.com/arsnebula) # \ Send and receive action requests between web components. * Can be used to implement a unidirectional data flow architecture * Uses a standard custom `dispatch` event to facilitate communication between elements * Listens for events on `window` so sender/receiver can be anywhere in document hierarchy * Uses a `Promise` to allow action handler to resolve or reject the action and notify caller ## Installation ```sh $ bower install -S arsnebula/nebula-dispatch ``` ## Getting Started Import the package. ```html ``` Use the `Nebula.DispatchBehavior` class extension mixin to add the `dispatchAction` method to any element. The `dispatchAction` method returns a `Promise` that allows the action handler to resolve or reject the action request. ```js class MyElement extends Nebula.DispatchBehavior(Polymer.Element) { static get is() { return 'my-element' } ready() { super.ready() this.dispatchAction('MY_ACTION', {message: 'Hello World'}).then( (message) => { console.log('Action completed:', message) }) } } ``` Use the `Nebula.DispatcherBehavior` class extension mixin to automatically receive dispatch events, and invoke action handlers. Methods on the dispatcher element will be automatically invoked if the method name matches the action type. ```js class MyActionsElement extends Nebula.DispatcherBehavior(Polymer.Element) { static get is() { return 'my-actions-element' } MY_ACTION(action) { try { // do stuff with payload const payload = action.payload action.resolve('Hello, nice to meet you') } catch(error) { action.reject(error) } } } ``` *For more information, see the API 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)