use-store-path v1.0.7

useStorePath

React hook for subscribe to redux store and force redraw component when specified path in the store changed

Usage

import { createStore } from 'redux';
import { Provider, useStore } from 'react-redux';
import { getUseStorePath } from 'use-store-path';

const store = createStore(reduce );

const exStore = {
  ...store,
  useStorePath: getUseStorePath(store),
}

const App = () => {
  return <Provider store={exStore} >
    <Container />
  </Provider>
}

const Container = () => {
  const { useStorePath } = useStore()
  const value1 = useStorePath([ 'path', 'to', 'value1' ])
  const value2 = useStorePath([ 'path', 'to', 'value2' ])
  return <Component value={value1} value2={value2} />
}

Usage with Typescript

interface Value {
    x: number;
    y: number;
}

const Container = () => {
  const { useStorePath } = useStore()
  const value1 = useStorePath<Value>([ 'path', 'to', 'value1' ])
  const value2 = useStorePath<Value>([ 'path', 'to', 'value2' ])
  return <Component value={value1} value2={value2} />
}

You can use only 'redux' and 'use-store-path' libraries without 'react-redux'

import { createStore } from 'redux';
import { getUseStorePath } from 'use-store-path';

const { dispatch, getState } = createStore(reduce);
const exStore = {
  ...store,
  useStorePath: getUseStorePath(store),
}
export const StoreContext = createContext<typeof extandedStore>(extandedStore);
export const useAppStore = () => useContext(StoreContext);

const App = () => {
  return <StoreContext.Provider store={exStore} >
    <Container />
  </StoreContext.Provider>
}

const Container = () => {
  const { useStorePath, dispatch } = useAppStore()
  const value1 = useStorePath([ 'path', 'to', 'value1' ])
  const value2 = useStorePath([ 'path', 'to', 'value2' ])
  return <Component value={value1} value2={value2} onChange={() => dispatch(actionX())} />
}

API

getUseStorePath({ subscribe, getState });

Parameters:

subscribe(listener) - Function that adds a change listener. (See redux documentation)

getState() - Function that return root state. (See redux documentation)

Returns:

Hook useStorePath()

useStorePath(path: string[]): any;

Parameters:

path: string[] - Path to the value in the state.

Returns:

Value in the selected path. If value not exists, return undefined

How it work

This library contains method getSubscribePath({ subscribe, getState }).
This function 1. add listener for the changes in the redux store 2. return 2 methods: subscribePath(path: string[], subscription: Subscription) getStateByPath(path: string[])

subscribePath - Function that adds subscription into internal object by specified path For example after call:

subscribePath([], subscription1)
subscribePath(['a','b'], subscription2)
subscribePath(['a','c'], subscription3)
subscribePath(['a','c'], subscription4)

Will created rootListener:

{
    subscribes: [ subscription1 ], children: {
        a: { subscribes: [], children: {
            b: { subscribes: [ subscription2 ] }
            c: { subscribes: [ subscription3, subscription4 ] }
        }}
    }
}

When redux state changed, then iterate rootListener and compare previous and new state on each node.

If state of this node changed, then subscription add to the fireQueue, and recursive iterate children nodes.

Then subscriptions one by one pull from fireQueue and call.

fireQueue resolve issue when new dispatch call inside subscription.