nebula-dispatch | Vaadin

Send and receive action requests between web components.

[ This description is mirrored from at on 2019-05-22 ]

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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


$ bower install -S arsnebula/nebula-dispatch

Getting Started

Import the package.

<link rel="import" href="/bower_components/nebula-dispatch/nebula-dispatch.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.

class MyElement extends Nebula.DispatchBehavior(Polymer.Element) {
  static get is() { return 'my-element' }
  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.

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) {

For more information, see the API documentation.


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 or directly on GitHub.

  • Submit a feature request, or a defect report on the Issues List.

  • Become a Patreon. It takes a lot of time and effort to develop, document, test and support the elements in our 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





Link to this version
ImportedReleased 01 May 2017ISC License
Framework Support
Polymer 1.0+
Polymer 2.0+
Browser Independent
Install with
bower install --save arsnebula/nebula-dispatch"#2.0.2"
Run the above Bower command in your project folder. If you have any issues installing, please contact the author.
Release notes - Version 2.0.2


  • polymer#Polymer/polymer#>=2.0.0-rc.1 <3.0
  • nebula-element-mixin#arsnebula/nebula-element-mixin#^2.0.0