redux-prefetcher

v0.0.2

Published

2 years ago

It allows you to do async actions before rendering the view.

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dweedon

redux react async props

ReduxConnect for React Router

How do you usually request data and store it to redux state? You create actions that do async jobs to load data, create reducer to save this data to redux state, then connect data to your component or container.

Usually it's very similar routine tasks.

Also, usually we want data to be preloaded. Especially if you're building universal app, or you just want pages to be solid, don't jump when data was loaded.

This package consist of 2 parts: one part allows you to delay containers rendering until some async actions are happening. Another stores your data to redux state and connect your loaded data to your container.

Notice

This is a fork and refactor of redux-async-connect

Installation & Usage

Using npm:

$ npm install redux-connect -S

import { Router, browserHistory } from 'react-router';
import { ReduxAsyncConnect, asyncConnect, reducer as reduxAsyncConnect } from 'redux-connect'
import React from 'react'
import { render } from 'react-dom'
import { createStore, combineReducers } from 'redux';

// 1. Connect your data, similar to react-redux @connect
@asyncConnect([{
  key: 'lunch',
  promise: ({ params, helpers }) => Promise.resolve({ id: 1, name: 'Borsch' })
}])
class App extends React.Component {
  render() {
    // 2. access data as props
    const lunch = this.props.lunch
    return (
      <div>{lunch.name}</div>
    )
  }
}

// 3. Connect redux async reducer
const store = createStore(combineReducers({ reduxAsyncConnect }), window.__data);

// 4. Render `Router` with ReduxAsyncConnect middleware
render((
  <Provider store={store} key="provider">
    <Router render={(props) => <ReduxAsyncConnect {...props}/>} history={browserHistory}>
      <Route path="/" component={App}/>
    </Router>
  </Provider>
), el)

Server

import { renderToString } from 'react-dom/server'
import { match, RoutingContext } from 'react-router'
import { ReduxAsyncConnect, loadOnServer, reducer as reduxAsyncConnect } from 'redux-connect'
import createHistory from 'history/lib/createMemoryHistory';
import { Provider } from 'react-redux';
import { createStore, combineReducers } from 'redux';
import serialize from 'serialize-javascript';

app.get('*', (req, res) => {
  const store = createStore(combineReducers({ reduxAsyncConnect }));

  match({ routes, location: req.url }, (err, redirect, renderProps) => {

    // 1. load data
    loadOnServer({ ...renderProps, store }).then(() => {

      // 2. use `ReduxAsyncConnect` instead of `RoutingContext` and pass it `renderProps`
      const appHTML = renderToString(
        <Provider store={store} key="provider">
          <ReduxAsyncConnect {...renderProps} />
        </Provider>
      )

      // 3. render the Redux initial data into the server markup
      const html = createPage(appHTML, store)
      res.send(html)
    })
  })
})

function createPage(html, store) {
  return `
    <!doctype html>
    <html>
      <body>
        <div id="app">${html}</div>

        <!-- its a Redux initial data -->
        <script dangerouslySetInnerHTML={{__html: `window.__data=${serialize(store.getState())};`}} charSet="UTF-8"/>
      </body>
    </html>
  `
}

API

Usage with `applyRouterMiddleware`

Thanks to @mmahalwy for a good usage example Pass custom render method to ReduxAsyncConnect, it can look like this:

// on client
const component = (
  <Router
    render={(props) => (
      <ReduxAsyncConnect
        {...props}
        helpers={{ client }}
        filter={item => !item.deferred}
        render={applyRouterMiddleware(useScroll())}
      />
    )}
    history={history}
    routes={getRoutes(store)}
  />
);

Basically what you do is instead of using render method like:

const render = props => <RouterContext {...props} />;

you use

const render = applyRouterMiddleware(...middleware);

Usage with `ImmutableJS`

This lib can be used with ImmutableJS or any other immutability lib by providing methods that convert the state between mutable and immutable data. Along with those methods, there is also a special immutable reducer that needs to be used instead of the normal reducer.

import { setToImmutableStateFunc, setToMutableStateFunc, immutableReducer as reduxAsyncConnect } from 'redux-connect';

// Set the mutability/immutability functions
setToImmutableStateFunc((mutableState) => Immutable.fromJS(mutableState));
setToMutableStateFunc((immutableState) => immutableState.toJS());

// Thats all, now just use redux-connect as normal
export const rootReducer = combineReducers({
  reduxAsyncConnect,
  ...
})

React Router Issue

While using the above immutablejs solution, an issue arose causing infinite recursion after firing off a react standard action. The recursion was caused because the componentWillReceiveProps method will attempt to resync with the server. Thus componentWillReceiveProps -> resync with server -> changes props via reducer -> componentWillReceiveProps

The solution was to only resync with server on route changes. A reloadOnPropsChange prop is expose on the ReduxAsyncConnect component to allow customization of when a resync to the server should occur.

Method signature (props, nextProps) => bool

const reloadOnPropsChange = (props, nextProps) => {
  // reload only when path/route has changed
  return props.location.pathname !== nextProps.location.pathname;
};

export const Root = ({ store, history }) => (
  <Provider store={store} key="provider">
    <Router render={(props) => <ReduxAsyncConnect {...props}
      reloadOnPropsChange={reloadOnPropsChange}/>} history={history}>
      {getRoutes(store)}
    </Router>
  </Provider>
);

Comparing with other libraries

There are some solutions of problem described above:

AsyncProps It solves the same problem, but it doesn't work with redux state. Also it's significantly more complex inside, because it contains lots of logic to connect data to props. It uses callbacks against promises...
react-fetcher It's very simple library too. But it provides you only interface for decorating your components and methods to fetch data for them. It doesn't integrated with React Router or Redux. So, you need to write you custom logic to delay routing transition for example.
react-resolver Works similar, but isn't integrated with redux.

Redux Connect uses awesome Redux to keep all fetched data in state. This integration gives you agility:

you can react on fetching actions like data loading or load success in your own reducers
you can create own middleware to handle Redux Async Connect actions
you can connect to loaded data anywhere else, just using simple redux @connect
finally, you can debug and see your data using Redux Dev Tools

Also it's integrated with React Router to prevent routing transition until data is loaded.

Contributors

Collaboration

You're welcome to PR, and we appreciate any questions or issues, please open an issue!

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