redux-window-message-thunk

A middleware that allows you to setup event handlers for window 'message' events.

How it works

This library allows for the creation of window.postMessage listeners associated with a set of callback functions and the dispatch the callback result through redux middleware. These callbacks are associated to the respective listener by matching the callback function name with the type property of the message data received, and are only dispatched if the origin matches a trusted domain from the domains array passed to the middleware.

Usage

npm install redux-window-message-thunk

Then in the place you're creating your redux store, add the middleware:

import { createStore, applyMiddleware } from 'redux';
import reduxWindowMessageThunk from 'redux-window-message-thunk';
import myReducerFn from './myReducer.js';

const messageCallbacks = {
  'MODAL_CLOSE': (data) => {
    const { someKey } = data
    return {
      type: 'HANDLE_MODAL_IN_PARENT',
      key: someKey
    }
  }
}

const myOrigins = ['https://my.project.dev']

const messageMiddleware = reduxWindowMessageThunk(myOrigins, messageCallbacks)

const store = createStore(
  myReducerFn,
  applyMiddleware(messageMiddleware)
);

Message callback thunk

A message callback should either be mapped an action as shown above or a thunk.

const messageCallbacks = {
  'MODAL_CLOSE': (data) => {
    return (dispatch, getState) => {
      const { someKey } = data;
      if (getState().allowedKey === someKey) {
        dispatch({
          type: 'HANDLE_MODAL_IN_PARENT',
          key: someKey
        })
      }
    }
  }
}

What's Happening

This will begin listening to all window message events. If an event comes along with a payload of the shape:

data: {
  type: 'MODAL_CLOSE',
  someKey: true,
},

It will look for a method on your messageCallbacks map, and if it finds it will pass your data to it and dispatch the result.

A part of the thunk-centric-redux set of tools

This library is part of a larger set of tools that can be helpful for making thunk-centric Redux applications. Visit that project to see a runnable example app that makes use of this code in context.

MIT License

Copyright (c) 2015-2019 Ian Taylor & Contributors

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.