[ React ] React 실전 ② 프로젝트 기초 공사 2

[ 상태 관리 ]

 

일기 데이터를 관리할 state를 App 컴포넌트에 작성하기

 

App.js

import React, { useReducer, useRef } from "react";

import { BrowserRouter, Route, Routes } from "react-router-dom";
import "./App.css";
import Home from "./pages/Home";
import Diary from "./pages/Diary";
import New from "./pages/New";
import Edit from "./pages/Edit";

// COMPONENTS
import MyButton from "./components/MyButton";
import MyHeader from "./components/MyHeader";

const reducer = (state, action) => {
  let newState = [];
  switch (action.type) {
    case "INIT": {
      return action.data;
    }
    case "CREATE": {
      const newItem = {
        ...action.data,
      };
      newState = [newItem, ...state];
      break;
    }
    case "REMOVE": {
      newState = state.filter((it) => it.id !== action.targetId);
      break;
    }
    case "EDIT": {
      newState = state.map((it) =>
        it.id === action.data.id ? { ...action.data } : it
      );
      break;
    }
  }

  return state;
};

export const DiaryStateContext = React.createContext();
export const DiaryDispatchContext = React.createContext();

function App() {
  const [data, dispatch] = useReducer(reducer, []);

  const dataId = useRef(0);
  //CREATE
  const onCreate = (date, content, emotion) => {
    dispatch({
      type: "CREATE",
      data: {
        id: dataId.current,
        data: new Date(date).getTime(),
        content,
        emotion,
      },
    });
    dataId.current += 1;
  };
  //REMOVE
  const onRemove = (targetId) => {
    dispatch({ type: "REMOVE", targetId });
  };
  //EDIT
  const onEdit = (targetId, date, content, emotion) => {
    dispatch({
      type: "EDIT",
      data: {
        id: dataId,
        data: new Date(date).getTime(),
        content,
        emotion,
      },
    });
  };

  return (
    <DiaryStateContext.Provider value={data}> 
      <DiaryDispatchContext.Provider value={(onCreate, onEdit, onRemove)}>
        <BrowserRouter>
          <div className="App">
            <Routes>
              <Route path="/" element={<Home />} />
              <Route path="/new" element={<New />} />
              <Route path="/diary/:id" element={<Diary />} />
              <Route path="/diary" element={<Diary />} />
              <Route path="/edit" element={<Edit />} />
            </Routes>
          </div>
        </BrowserRouter>
      </DiaryDispatchContext.Provider>
    </DiaryStateContext.Provider>
  );
}

export default App;