cornflux

cornflux (beta)

A library for dispatching events in a React application using the react context as a data bus.

Motivation

The TL;DR version: data isolation. Protect your application data and state storage in components that can only be interfaced with via actions.

The longer version can be found in this post on medium if you have the patience.

Installation

# make sure you have the dependencies first:
npm install --save react react-dom react-schema
npm install --save cornflux

Usage

There are two conceptual types provided by the library; action providers and action emitters.

Action providers are components that perform actions, while action emitters are ones that request an action be performed.

Handling actions

Construct an "acting" version of the component that should be performing side-effects with the ActionProvider decorator and define the action handlers:

import { ActionProvider } from 'cornflux';
import DataConsumer from './DataConsumer';

const DataProvider = React.createClass({
  getInitialState() {
    return { count: 0 };
  },

  render() {
    return <DataConsumer count={this.state.count}
  }
});

const ActingDataProvider = ActionProvider(DataProvider, {
  actions: [
    ADJUST_COUNT(component, payload) {
      component.setState({ count: payload.count });
    }
  ]
});

export default MyActingComponent;

Triggering actions

Construct an "emitting" version of the component that needs to request an action be performed with the ActionEmitter decorator. You must explicitly specify the list of action names that it will trigger.

import { ActionEmitter } from 'cornflux';

const DataConsumer = React.createClass({
  render() {
    return React.createElement('button', {
      onClick: this.incrementCounter
    });
  },

  incrementCounter() {
    this.props.dispatch('ADJUST_COUNT', { count: this.props.count + 1 });
  }
});

const EmittingDataConsumer = ActionEmitter(DataConsumer, {
  actions: [
    'ADJUST_COUNT'
  ]
});

export default EmittingDataConsumer;

That's really it. What you use for storing and manipulating data is of no relevance to cornflux. You can use Redux, Ember, Backbone, or whatever you want.

API Reference

ActionProvider: (Component, options: Object) -> Component

The options are as follows:

!actions: Object.<{ String, Function }>

The actions that are provided by the component. The keys are the action identifiers (and that's what emitters will be using to request it) and the values are the actual handlers.

The handler signature is as such:

(
  state: Object,
  payload: Object,
  Object.<{
    dispatch: (String, Object) -> Any,
    propagate: () -> Any
  }>
) -> Any

The first argument, state, is either the reduced state of the container if a reducer was defined, otherwise it's the component instance itself.

The payload argument is the action payload that was provided when the action was emitted.

The third argument is an object containing two functions:

• dispatch which lets your handler dispatch other events. The signature is is similar to emitter's dispatch.
• propagate is a callback for yielding (or "bubbling") the action to a provider higher in the chain. Note that it accepts NO parameters, the action is yielded as-is.

?displayName: String

A custom display name for the decorated component.

Defaults to: ActionProvider($ORIGINAL_COMPONENT_DISPLAY_NAME)

?reducer: (component) -> Object

A funcion for "reducing" the component instance into some state that the action handlers need.

This option gives you a greater degree of what the action handlers may end up touching, if you're really paranoid.

Defaults to: (x) -> x. The identity function where the component instance itself is passed through.

?serviceWrapper: (Any) -> Any

Compatibility option for applications that use promises or relied on earlier dispatchers always generating promises (or something alike.)

The function will receive the return value of the action handler and can augment it in any way it sees fit.

Defaults to: (x) -> x

?verbose: Boolean

Turn this on if you want diagnostic messages be output to the console for debugging.

Defaults to: false

ActionEmitter: (Component, options: Object) -> Component

!actions: Array.<String>

The list of actions that the component is expected to emit. At run-time, the actions you list will be verified to be provided by some ActionProvider up the tree, otherwise a warning will be logged.

?propName: String

The name of the prop that will be passed down to the decorated component to use for dispatching actions.

Defaults to: dispatch

License

The MIT license.