fusion-plugin-redux-action-emitter-enhancer

Redux store enhancer that emits actions via an injected event emitter.

The fusion-plugin-redux-action-emitter-enhancer provides a Redux compatible store enhancer. This plugin composes a new, enhanced store creator, which captures and emits all dispatched actions.

This is useful for when you want to collect data about redux actions, potentially to recreate user journeys or statefulness.

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Table of contents

• Installation
• Usage
  • Capturing action emits
  • Transforming action payloads on emission
• Setup
• API
  • Registration API
    • ReduxActionEmitterEnhancer
    • EnhancerToken
    • ActionEmitterTransformerToken
  • Dependencies
  • Service API
  • Emit API

---

Installation

yarn add fusion-plugin-redux-action-emitter-enhancer

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Usage

Capturing action emits

We can register a simple callback to listen for the events emitted by this enhancer - in this case, redux-action-emitter:action. Normally we might want to log these to a backend service, but for simplicity, we'll log them to console.

// src/plugins/some-emit-consumer.js
export default createPlugin({
  deps: {events: UniversalEventsToken},
  middleware: ({events}) => {
    events.on('redux-action-emitter:action', payload => {
      console.log("Action emitted: ", payload);
    });
  }
});

Transforming action payloads on emission

This plugin depends on fusion-plugin-universal-events to emit the action payloads, which means the payloads are sent over-the-wire to the server-side, which can consume much of the network bandwidth, or even cause 413 Payload Too Large HTTP errors. The dependence is the reason why by default the plugin will only emit certain properties from the raw action payload.

By default, _trackingMeta is an opinionated property to be picked and emitted from the raw payload for tracking(analytics) purposes. For customizations, you should provide a transformer function to mainly filter/pick properties for emission.

// src/app.js
import {ActionEmitterTransformerToken} from 'fusion-plugin-redux-action-emitter-enhancer';

app.register(ActionEmitterTransformerToken, action => {
  const base = {type: action.type};
  switch (action.type) {
    case 'ADD_TO_SHOPPING_CART':
    case 'REMOVE_FROM_SHOPPING_CART':
      return {
        ...base,
        items: action.payload.items,
      };
    case 'ADD_COUPON': {
      return {
        ...base,
        couponId: action.payload.couponId,
      };
    }
    case 'SUPER_BIG_PAYLOAD':
      return null; // !!Omit the action type from emission entirely!!
    default:
      return base;
  }
});

Or, if you are certain about emitting everything from the raw payload, maybe when bandwidth is actually not a concern for your application:

app.register(ActionEmitterTransformerToken, action => action);

---

Setup

// src/main.js
import UniversalEvents, {UniversalEventsToken} from 'fusion-plugin-universal-events';
import {FetchToken} from 'fusion-tokens';
import Redux, {ReduxToken, ReducerToken, EnhancerToken} from 'fusion-plugin-react-redux';
import fetch from 'unfetch';
import ReduxActionEmitterEnhancer from 'fusion-plugin-redux-action-emitter-enhancer';
import reducer from './reducers/root.js'

export default function start() {
  const app = new App(root);

  app.register(UniversalEventsToken, UniversalEvents, {fetch});
  __BROWSER__ && app.register(FetchToken, fetch);

  app.register(ReduxToken, Redux);
  app.register(ReducerToken, reducer);
  app.register(EnhancerToken, ReduxActionEmitterEnhancer);

  return app;
}

// src/reducers/root.js
export default (state, action) => {
  // reducer goes here
}

---

API

Registration API

ReduxActionEmitterEnhancer

import ReduxActionEmitterEnhancer from 'fusion-plugin-redux-action-emitter-enhancer';

This plugin. It can be registered as a dependency to any plugin that expects a Redux Store Enhancer. Typically, it should be registered with EnhancerToken.

EnhancerToken

import {EnhancerToken} from 'fusion-plugin-react-redux';

If you are using fusion-plugin-react-redux, we recommend registering this plugin to the EnhancerToken.

ActionEmitterTransformerToken

import {ActionEmitterTransformerToken} from 'fusion-plugin-redux-action-emitter-enhancer';

Default transformer

action => ({type: action.type, _trackingMeta: action._trackingMeta})

Providing a transform function for the raw action payloads. See "Transforming action payloads on emission" for more information.

Dependencies

import UniversalEvents, {UniversalEventsToken} from 'fusion-plugin-universal-events';

app.register(UniversalEventsToken, UniversalEvents);

An event emitter plugin which emits the actions. Typically, it is registered with fusion-plugin-universal-events.

Service API

type StoreEnhancer = (next: StoreCreator) => StoreCreator

This plugin provides a Redux compatible store enhancer.

Emit API

To consume action events, add an event listener for the following emitted events:

• redux-action-emitter:action

The payload is the Redux action itself.