CacheRoute

English | 中文说明

Route with cache for react-router like keep-alive in Vue.

If you want <KeepAlive /> only, try react-activation

React v15+

React-Router v4+

Problem

Using Route, component can not be cached while going forward or back which lead to losing data and interaction

Reason & Solution

Component would be unmounted when Route was unmatched

After reading source code of Route we found that using children prop as a function could help to control rendering behavior.

Hiding instead of Removing would fix this issue.

https://github.com/ReactTraining/react-router/blob/master/packages/react-router/modules/Route.js#L41-L63

Install

npm install react-router-cache-route --save
# or
yarn add react-router-cache-route

Usage

Replace Route with CacheRoute

Replace Switch with CacheSwitch (Because Switch only keeps the first matching state route and unmount the others)

import React from 'react'
import { HashRouter as Router, Route } from 'react-router-dom'
import CacheRoute, { CacheSwitch } from 'react-router-cache-route'

import List from './views/List'
import Item from './views/Item'

const App = () => (
  <Router>
    <CacheSwitch>
      <CacheRoute exact path="/list" component={List} />
      <Route exact path="/item/:id" component={Item} />
      <Route render={() => <div>404 Not Found</div>} />
    </CacheSwitch>
  </Router>
)

export default App

CacheRoute props

name	type	default	description
when	`String` / `Function`	`"forward"`	Decide when to cache
className	`String`	-	`className` prop for the wrapper component
behavior	`Function`	`cached => cached ? { style: { display: "none" }} : undefined`	Return `props` effective on the wrapper component to control rendering behavior
cacheKey	`String`	-	For imperative control caching
multiple (React v16.2+)	`Boolean` / `Number`	`false`	Allows different caches to be distinguished by dynamic routing parameters. When the value is a number, it indicates the maximum number of caches. When the maximum value is exceeded, the oldest updated cache will be cleared.
unmount (UNSTABLE)	`Boolean`	`false`	Whether to unmount the real dom node after cached, to save performance (Will cause losing the scroll position after recovered, fixed with `saveScrollPosition` props)
saveScrollPosition (UNSTABLE)	`Boolean`	`false`	Save scroll position

CacheRoute is only a wrapper component that works based on the children property of Route, and does not affect the functionality of Route itself.

For the rest of the properties, please refer to https://reacttraining.com/react-router/

About `when`

The following values can be taken when the type is String

[forward] Cache when forward behavior occurs, corresponding to the PUSH or REPLACE action in react-router
[back] Cache when back behavior occurs, corresponding to the POP action in react-router
[always] Always cache routes when leave, no matter forward or backward

When the type is Function, the component's props will be accepted as the first argument, return true/false to determine whether to cache.

CacheSwitch props

name	type	default	description
which	`Function`	`element => element.type === CacheRoute`	`<CacheSwitch>` only saves the first layer of nodes which type is `CacheRoute` by default, `which` prop is a function that would receive a instance of React Component, return `true/false` to decide if `<CacheSwitch>` need to save it, reference #55

Lifecycles

Component with CacheRoute will accept one prop named cacheLifecycles which contains two functions to inject customer Lifecycle didCache and didRecover

import React, { Component } from 'react'

export default class List extends Component {
  constructor(props) {
    super(props)

    props.cacheLifecycles.didCache(this.componentDidCache)
    props.cacheLifecycles.didRecover(this.componentDidRecover)
  }

  componentDidCache = () => {
    console.log('List cached')
  }

  componentDidRecover = () => {
    console.log('List recovered')
  }

  render() {
    return (
      // ...
    )
  }
}

Drop cache manually

You can manually control the cache with cacheKey prop and dropByCacheKey function.

import CacheRoute, { dropByCacheKey, getCachingKeys } from 'react-router-cache-route'

...
<CacheRoute ... cacheKey="MyComponent" />
...

console.log(getCachingKeys()) // will receive ['MyComponent'] if CacheRoute is cached which `cacheKey` prop is 'MyComponent'
...

dropByCacheKey('MyComponent')
...

remaxjs/react-router-cache-route