react-model

react-model ·

The State management library for React

🎉 Support Both Class and Hooks Api

⚛️ Support preact, react-native and Next.js

⚔ Full TypeScript Support

📦 Built with microbundle

⚙️ Middleware Pipline ( redux-devtools support ... )

☂️ 100% test coverage, safe on production

🐛 Debug easily on test environment

import { Model } from 'react-model'

// define model
const Todo = {
  state: {
    items: ['Install react-model', 'Read github docs', 'Build App']
  },
  actions: {
    add: todo => {
      // s is the readonly version of state
      // you can also return partial state here but don't need to keep immutable manually
      // state is the mutable state
      return state => {
        state.items.push(todo)
      }
    }
  }
}

// Model Register
const { useStore } = Model(Todo)

const App = () => {
  return <TodoList />
}

const TodoList = () => {
  const [state, actions] = useStore()
  return <div>
    <Addon handler={actions.add} />
    {state.items.map((item, index) => (<Todo key={index} item={item} />))}
  </div>
}

---

Recently Updated

• feat(middleware): support enable/disable sepecific middleware
• fix(stateupdater): fix the issue that setState on unmounted component

Quick Start

CodeSandbox: TodoMVC

Next.js + react-model work around

v2 docs

install package

npm install react-model

Table of Contents

• Core Concept
  • Model
  • Model Register
  • useStore
  • getState
  • actions
  • subscribe
• Advance Concept
  • immutable Actions
  • SSR with Next.js
  • Middleware
  • Expand Context
• Other Concept required by Class Component
  • Provider
  • connect
• FAQ
  • Migrate from 3.1.x to 4.x.x
  • How can I disable the console debugger?
  • How can I add custom middleware
    • How can I make persist models
  • How can I deal with local state
  • How can I deal with huge dataset / circular dataset
  • actions throw error from immer.module.js
  • How can I customize each model's middlewares?

Core Concept

Model

Every model has its own state and actions.

const initialState = {
  counter: 0,
  light: false,
  response: {}
}

interface StateType {
  counter: number
  light: boolean
  response: {
    code?: number
    message?: string
  }
}

interface ActionsParamType {
  increment: number
  openLight: undefined
  get: undefined
} // You only need to tag the type of params here !

const model: ModelType<StateType, ActionsParamType> = {
  actions: {
    increment: async (payload, { state }) => {
      return {
        counter: state.counter + (payload || 1)
      }
    },
    openLight: async (_, { state, actions }) => {
      await actions.increment(1) // You can use other actions within the model
      await actions.get() // support async functions (block actions)
      actions.get()
      await actions.increment(1) // + 1
      await actions.increment(1) // + 2
      await actions.increment(1) // + 3 as expected !
      return { light: !state.light }
    },
    get: async () => {
      await new Promise((resolve, reject) =>
        setTimeout(() => {
          resolve()
        }, 3000)
      )
      return {
        response: {
          code: 200,
          message: `${new Date().toLocaleString()} open light success`
        }
      }
    }
  },
  state: initialState
}

export default model

// You can use these types when use Class Components.
// type ConsumerActionsType = getConsumerActionsType<typeof Model.actions>
// type ConsumerType = { actions: ConsumerActionsType; state: StateType }
// type ActionType = ConsumerActionsType
// export { ConsumerType, StateType, ActionType }

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Model Register

react-model keeps the application state and actions in separate private stores. So you need to register them if you want to use them as the public models.

model/index.ts

import { Model } from 'react-model'
import Home from '../model/home'
import Shared from '../model/shared'

const models = { Home, Shared }

export const { getInitialState, useStore, getState, actions, subscribe, unsubscribe } = Model(models)

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useStore

The functional component in React ^16.8.0 can use Hooks to connect the global store. The actions returned from useStore can invoke dom changes.

The execution of actions returned by useStore will invoke the rerender of current component first.

It's the only difference between the actions returned by useStore and actions now.

import React from 'react'
import { useStore } from '../index'

// CSR
export default () => {
  const [state, actions] = useStore('Home')
  const [sharedState, sharedActions] = useStore('Shared')

  return (
    <div>
      Home model value: {JSON.stringify(state)}
      Shared model value: {JSON.stringify(sharedState)}
      <button onClick={e => actions.increment(33)}>home increment</button>
      <button onClick={e => sharedActions.increment(20)}>
        shared increment
      </button>
      <button onClick={e => actions.get()}>fake request</button>
      <button onClick={e => actions.openLight()}>fake nested call</button>
    </div>
  )
}

optional solution on huge dataset (example: TodoList(10000+ Todos)):

1. use useStore on the subComponents which need it.
2. use useStore selector. (version >= v4.0.0-rc.0)

advance example with 1000 todo items

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getState

Key Point: State variable not updating in useEffect callback

To solve it, we provide a way to get the current state of model: getState

Note: the getState method cannot invoke the dom changes automatically by itself.

Hint: The state returned should only be used as readonly

import { useStore, getState } from '../model/index'

const BasicHook = () => {
  const [state, actions] = useStore('Counter')
  useEffect(() => {
    console.log('some mounted actions from BasicHooks')
    return () =>
      console.log(
        `Basic Hooks unmounted, current Counter state: ${JSON.stringify(
          getState('Counter')
        )}`
      )
  }, [])
  return (
    <>
      <div>state: {JSON.stringify(state)}</div>
    </>
  )
}

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actions

You can call other models' actions with actions api

actions can be used in both class components and functional components.

import { actions } from './index'

const model = {
  state: {},
  actions: {
    crossModelCall: () => {
      actions.Shared.changeTheme('dark')
      actions.Counter.increment(9)
    }
  }
}

export default model

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subscribe

subscribe(storeName, actions, callback) run the callback when the specific actions executed.

import { subscribe, unsubscribe } from './index'

const callback = () => {
  const user = getState('User')
  localStorage.setItem('user_id', user.id)
}

// subscribe action
subscribe('User', 'login', callback)
// subscribe actions
subscribe('User', ['login', 'logout'], callback)
// unsubscribe the observer of some actions
unsubscribe('User', 'login') // only logout will run callback now

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Advance Concept

immutable Actions

The actions use immer produce API to modify the Store. You can return a producer in action.

Using function as return value can make your code cleaner when you modify the deep nested value.

TypeScript Example

// StateType and ActionsParamType definition
// ...

const model: ModelType<StateType, ActionsParamType> = {
  actions: {
    increment: async (params, { state: s }) => {
      // return (state: typeof s) => { // TypeScript < 3.9
      return state => {
        state.counter += params || 1
      }
    },
    decrease: params => s => {
      s.counter += params || 1
    }
  }
}

export default model

JavaScript Example

const Model = {
  actions: {
    increment: async (params) => {
      return state => {
        state.counter += params || 1
      }
    }
  }
}

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SSR with Next.js

Store: shared.ts

const initialState = {
  counter: 0
}

const model: ModelType<StateType, ActionsParamType> = {
  actions: {
    increment: (params, { state }) => {
      return {
        counter: state.counter + (params || 1)
      }
    }
  },
  // Provide for SSR
  asyncState: async context => {
    await waitFor(4000)
    return { counter: 500 }
  },
  state: initialState
}

export default model

Global Config: _app.tsx

import { models, getInitialState, Models } from '../model/index'

let persistModel: any

interface ModelsProps {
  initialModels: Models
  persistModel: Models
}

const MyApp = (props: ModelsProps) => {
  if ((process as any).browser) {
    // First come in: initialModels
    // After that: persistModel
    persistModel = props.persistModel || Model(models, props.initialModels)
  }
  const { Component, pageProps, router } = props
  return (
    <Container>
      <Component {...pageProps} />
    </Container>
  )
}

MyApp.getInitialProps = async (context: NextAppContext) => {
  if (!(process as any).browser) {
    const initialModels = context.Component.getInitialProps
      ? await context.Component.getInitialProps(context.ctx)
      await getInitialState(undefined, { isServer: true }) // get all model initialState
      // : await getInitialState({ modelName: 'Home' }, { isServer: true }) // get Home initialState only
      // : await getInitialState({ modelName: ['Home', 'Todo'] }, { isServer: true }) // get multi initialState
      // : await getInitialState({ data }, { isServer: true }) // You can also pass some public data as asyncData params.
    return { initialModels }
  } else {
    return { persistModel }
  }
}

Page: hooks/index.tsx

import { useStore, getState } from '../index'
export default () => {
  const [state, actions] = useStore('Home')
  const [sharedState, sharedActions] = useStore('Shared')

  return (
    <div>
      Home model value: {JSON.stringify(state)}
      Shared model value: {JSON.stringify(sharedState)}
      <button
        onClick={e => {
          actions.increment(33)
        }}
      >
    </div>
  )
}

Single Page Config: benchmark.tsx

// ...
Benchmark.getInitialProps = async () => {
  return await getInitialState({ modelName: 'Todo' }, { isServer: true })
}

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Middleware

We always want to try catch all the actions, add common request params, connect Redux devtools and so on. We Provide the middleware pattern for developer to register their own Middleware to satisfy the specific requirement.

// Under the hood
const tryCatch: Middleware<{}> = async (context, restMiddlewares) => {
  const { next } = context
  await next(restMiddlewares).catch((e: any) => console.log(e))
}

// ...

let actionMiddlewares = [
  tryCatch,
  getNewState,
  setNewState,
  stateUpdater,
  communicator,
  devToolsListener
]

// ...
// How we execute an action
const consumerAction = (action: Action) => async (params: any) => {
  const context: Context = {
    modelName,
    setState,
    actionName: action.name,
    next: () => {},
    newState: null,
    params,
    consumerActions,
    action
  }
  await applyMiddlewares(actionMiddlewares, context)
}

// ...

export { ... , actionMiddlewares}

⚙️ You can override the actionMiddlewares and insert your middleware to specific position

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Expand Context

const ExtCounter: ModelType<
  { name: string }, // State Type
  { ext: undefined }, // ActionParamsType
  { name: string } // ExtContextType
> = {
  actions: {
    // { state, action } => { state, action, [name] }
    ext: (_, { name }) => {
      return { name }
    }
  },
  state: { name: '' }
}

const { useStore } = Model(ExtCounter, { name: 'test' })
// state.name = ''
const [state, actions] = useStore()
// ...
actions.ext()
// state.name => 'test'

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Other Concept required by Class Component

Provider

The global state standalone can not effect the react class components, we need to provide the state to react root component.

import { PureComponent } from 'react'
import { Provider } from 'react-model'

class App extends PureComponent {
  render() {
    return (
      <Provider>
        <Counter />
      </Provider>
    )
  }
}

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connect

We can use the Provider state with connect.

Javascript decorator version

import React, { PureComponent } from 'react'
import { Provider, connect } from 'react-model'

const mapProps = ({ light, counter }) => ({
  lightStatus: light ? 'open' : 'close',
  counter
}) // You can map the props in connect.

@connect(
  'Home',
  mapProps
)
export default class JSCounter extends PureComponent {
  render() {
    const { state, actions } = this.props
    return (
      <>
        <div>states - {JSON.stringify(state)}</div>
        <button onClick={e => actions.increment(5)}>increment</button>
        <button onClick={e => actions.openLight()}>Light Switch</button>
      </>
    )
  }
}

TypeScript Version

import React, { PureComponent } from 'react'
import { Provider, connect } from 'react-model'
import { StateType, ActionType } from '../model/home'

const mapProps = ({ light, counter, response }: StateType) => ({
  lightStatus: light ? 'open' : 'close',
  counter,
  response
})

type RType = ReturnType<typeof mapProps>

class TSCounter extends PureComponent<
  { state: RType } & { actions: ActionType }
> {
  render() {
    const { state, actions } = this.props
    return (
      <>
        <div>TS Counter</div>
        <div>states - {JSON.stringify(state)}</div>
        <button onClick={e => actions.increment(3)}>increment</button>
        <button onClick={e => actions.openLight()}>Light Switch</button>
        <button onClick={e => actions.get()}>Get Response</button>
        <div>message: {JSON.stringify(state.response)}</div>
      </>
    )
  }
}

export default connect(
  'Home',
  mapProps
)(TSCounter)

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FAQ

Migrate from 3.1.x to 4.x.x

1. remove Model wrapper

sub-model.ts

// 3.1.x
export default Model(model)
// 4.x.x
export default model

models.ts

import Sub from './sub-model'
export default Model({ Sub })

1. use selector to replace depActions

Shared.ts

interface State {
  counter: number
  enable: boolean
}

interface ActionParams {
  add: number
  switch: undefined
}

const model: ModelType<State, ActionParams> = {
  state: {
    counter: 1
    enable: false
  },
  actions: {
    add: (payload) => state => {
      state.counter += payload
    },
    switch: () => state => {
      state.enable = !state.enable
    }
  }
}

const Component = () => {
  // 3.1.x, Component rerender when add action is invoked
  const [counter] = useStore('Shared', ['add'])
  // 4.x.x, Component rerender when counter value diff
  const [counter] = useStore('Shared', state => state.counter)
}

How can I disable the console debugger

import { middlewares } from 'react-model'
// Find the index of middleware

// Disable all actions' log
middlewares.config.logger.enable = false
// Disable logs from specific type of actions
middlewares.config.logger.enable = ({ actionName }) => ['increment'].indexOf(actionName) !== -1

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How can I add custom middleware

import { actionMiddlewares, middlewares, Model } from 'react-model'
import { sendLog } from 'utils/log'
import Home from '../model/home'
import Shared from '../model/shared'

// custom middleware
const ErrorHandler: Middleware = async (context, restMiddlewares) => {
  const { next } = context
  await next(restMiddlewares).catch((e: Error) => sendLog(e))
}

// Find the index of middleware
const getNewStateMiddlewareIndex = actionMiddlewares.indexOf(
  middlewares.getNewState
)

// Replace it
actionMiddlewares.splice(getNewStateMiddlewareIndex, 0, ErrorHandler)

const stores = { Home, Shared }

export default Model(stores)

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How can I make persist models

import { actionMiddlewares, Model } from 'react-model'
import Example from 'models/example'

// Example, not recommend to use on production directly without consideration
// Write current State to localStorage after action finish
const persistMiddleware: Middleware = async (context, restMiddlewares) => {
  localStorage.setItem('__REACT_MODEL__', JSON.stringify(context.Global.State))
  await context.next(restMiddlewares)
}

// Use on all models
actionMiddlewares.push(persistMiddleware)
Model({ Example }, JSON.parse(localStorage.getItem('__REACT_MODEL__')))

// Use on single model
const model = {
  state: JSON.parse(localStorage.getItem('__REACT_MODEL__'))['you model name']
  actions: { ... },
  middlewares: [...actionMiddlewares, persistMiddleware]
}

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How can I deal with local state

What should I do to make every Counter hold there own model? 🤔

class App extends Component {
  render() {
    return (
      <div className="App">
        <Counter />
        <Counter />
        <Counter />
      </div>
    )
  }
}

Counter model

interface State {
  count: number
}

interface ActionParams {
  increment: number
}

const model: ModelType<State, ActionParams> = {
  state: {
    count: 0
  },
  actions: {
    increment: payload => {
      // immer.module.js:972 Uncaught (in promise) Error: An immer producer returned a new value *and* modified its draft. Either return a new value *or* modify the draft
      // Not allowed
      // return state => (state.count += payload)
      return state => {
        state.count += payload
      }
    }
  }
}

Counter.tsx

const Counter = () => {
  const [{ useStore }] = useState(() => Model(model))
  const [state, actions] = useStore()
  return (
    <div>
      <div>{state.count}</div>
      <button onClick={() => actions.increment(3)}>Increment</button>
    </div>
  )
}

export default Counter

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How can I deal with huge dataset / circular dataset

Immer assumes your state to be a unidirectional tree. That is, no object should appear twice in the tree, there should be no circular references.

Immer freezes everything recursively, for large data objects that won't be changed in the future this might be over-kill, in that case it can be more efficient to shallowly pre-freeze data using the freeze utility.

import { freeze } from 'immer'

export const ExpensiveModel: ModelType<ExpensiveState, ExpensiveActionParams> = {
  state: {
    moduleList: []
  },
  actions: {
    setPreFreezedDataset: () => {
      const optimizedDataset = freeze(hugeDataset)
      return { moduleList: optimizedDataset }
    }
  }
}

actions throw error from immer.module.js

immer.module.js:972 Uncaught (in promise) Error: An immer producer returned a new value *and* modified its draft. Either return a new value *or* modify the draft

How to fix:

actions: {
  increment: payload => {
    // Not allowed
    // return state => (state.count += payload)
    return state => {
      state.count += payload
    }
  }
}

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How can I customize each model's middlewares?

You can customize each model's middlewares.

import { actionMiddlewares, Model } from 'react-model'
const delayMiddleware: Middleware = async (context, restMiddlewares) => {
  await timeout(1000, {})
  context.next(restMiddlewares)
}

const nextCounterModel: ModelType<CounterState, NextCounterActionParams> = {
  actions: {
    add: num => {
      return state => {
        state.count += num
      }
    },
    increment: async (num, { actions }) => {
      actions.add(num)
      await timeout(300, {})
    }
  },
  // You can define the custom middlewares here
  middlewares: [delayMiddleware, ...actionMiddlewares],
  state: {
    count: 0
  }
}

export default Model(nextCounterModel)

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