nebula-dispatch - Vaadin Add-on Directory
Send and receive action requests between web components.
**[ 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)