Redux Handler Middleware

Middleware that executes custom handlers before and after state updates. This can be especially useful for handling navigation redirects.

Install

npm install redux-handler-middleware --save

Quick Example

middleware/handlerMiddleware.js

import browserHistory from 'react-router/lib/browserHistory';
import createHandlerMiddleware from 'redux-handler-middleware';
import {FETCH_POST_FAILURE, FETCH_POSTS_FAILURE} from 'constants/blog';

const handlerMiddleware = createHandlerMiddleware([{
    actions: [FETCH_POSTS_FAILURE, FETCH_POST_FAILURE],
    afterHandler: (store, action) => {
        if(action.payload.status === 404){
            browserHistory.push('/404');
        }
    }
}]);

export default handlerMiddleware;

store/createStore.js

import { createStore, applyMiddleware, combineReducers } from 'redux';
import handlerMiddleware from 'middleware/handlerMiddleware';
import rootReducer from 'reducers';

export default createStore(
    rootReducer,
    {},
    applyMiddleware(handlerMiddleware)
);

So now when a FETCH_POSTS_FAILURE or a FETCH_POST_FAILURE action is dispatched, the afterHandler will be invoked after the state updates and it will redirect you to /404. This provides a simple and intuitive solution to navigating in response to actions.

Usage

createHandlerMiddleware - Function

Must be passed an array of plain objects.

Defining Handlers

action - String

The type of the action. This is used when determining which handlers to fire.

actions - Array of actions

This is useful when multiple action types use the same handler.

beforeHandler - Function

Handler to be called before the state is updated.

afterHandler - Function

Handler to be called after the state is updated.

Special Thanks

to Diego Castillo who came up with the original idea in his blog post.