React Redux Boilerplate

index.js

/**
 * Folder structure
 */ 
 
 src
 -- redux
 -- -- action
 -- -- -- builder.js
 -- -- -- counter.js
 -- -- reducer
 -- -- -- builder.js
 -- -- -- counter.js
 -- -- -- rootReducer.js
 
 /**
 * 1. Create the reducer: reducer/builder.js
 */ 
 
// Use immer for create the next immutable state tree by simply modifying the current tree.
import produce from 'immer';

// The state should always be defined.
const initialState = {
	arr: ""
}

export default function builder (state = initialState, action) {
	console.log('reducer', state, action)
	switch(action.type) {
		case 'PUSH':
			return produce(state, draft => {
				draft.arr += 'X'
			})
		case 'SLICE':
			return produce(state, draft => {
				draft.arr = draft.arr.substring(0, draft.arr.length-1)
			})
		case 'CLEAR':
			return produce(state, draft => {
				draft.arr = ""
			})
		default:
			return state
	}
}

 /**
 * 2. Create the action creators and types: action/builder.js
 */ 

/**
 * Action Types
 * Sometimes it's a good idea to put them in a seperate file.
 */ 

export const PUSH = 'PUSH'
export const SLICE = 'SLICE'
export const CLEAR = 'CLEAR'

 /**
  * Action Creators
  */

export function push () {
	return {
		type: PUSH
	}
}

export const slice = () => {
	return {
		type: SLICE
	}
}

export const clear = () => ({ type: CLEAR })

 /**
 * 3. Register the reducer at the rootReducer: reducer/rootReducer.js
 */ 

import { combineReducers } from "redux";
import counter from "./counter"
import builder from "./builder"


export default combineReducers({
	counter,
	builder
});

 /**
 * 4. Connect your components: Builder.js
 */ 

import React from 'react'
import { connect } from 'react-redux'

import { push, slice, clear } from './redux/actions/builder'

const mapStateToProps = (state) => {
	return {
		arr: state.builder.arr,
	}
}

const mapDispatchToProps = {
	push,
	slice,
	clear
}

function Builder (props) {
	// const [count, setCount] = useState(0)
	// now count is part of the state (this.state.count)
	// not a setter is available: setCount(0)
	// useState(<initialValue>)

	const _push = () => {
		props.push()
	}

	const _slice = () => {
		props.slice()
	}

	const _clear = () => {
		props.clear()
	}

	return (
		<div>
        <h2>Builder</h2>
        <div>
          <button onClick={_slice}>-</button>
          <span>{props.arr}</span>
          <button onClick={_push}>+</button>
        </div>
		<div>
			<button onClick={_clear}>Reset</button>
		</div>
      </div>
	)
}

export default connect(mapStateToProps, mapDispatchToProps)(Builder)