我如何从 React-Redux 中的 reducer 中的状态更新对象数组中单个元素的名称字段？

Question

以下是我的减速器的初始状态：

const InitialState = {
    data:[],
    SelectUser : null,
    name: "Not Yet Selected"
};

下面是我从 api 获取的数据 [] 状态：

[
 {
  "id": 1,
  "name": "Leanne Graham",
  "username": "Bret",
  "email": "Sincere@april.biz",
  "address": {
    "street": "Kulas Light",
    "suite": "Apt. 556",
    "city": "Gwenborough",
    "zipcode": "92998-3874",
    "geo": {
      "lat": "-37.3159",
      "lng": "81.1496"
    }
  },
  "phone": "1-770-736-8031 x56442",
  "website": "hildegard.org",
  "company": {
    "name": "Romaguera-Crona",
    "catchPhrase": "Multi-layered client-server neural-net",
    "bs": "harness real-time e-markets"
  }
 },
 {
  "id": 2,
  "name": "Ervin Howell",
  "username": "Antonette",
  "email": "Shanna@melissa.tv",
  "address": {
    "street": "Victor Plains",
    "suite": "Suite 879",
    "city": "Wisokyburgh",
    "zipcode": "90566-7771",
    "geo": {
      "lat": "-43.9509",
      "lng": "-34.4618"
    }
  },
  "phone": "010-692-6593 x09125",
  "website": "anastasia.net",
  "company": {
    "name": "Deckow-Crist",
    "catchPhrase": "Proactive didactic contingency",
    "bs": "synergize scalable supply-chains"
  }
 }
]

我想将 name 从 state data[]中的对象更改为 state name 。 其中object的id与SelecUser状态object中的id相同。 SelectUser也是一个对象，其内容与data[]中的元素相同。 所有状态都已设置。

以下是迄今为止创建的减速器：

const InitialState = {
    data:[],
    SelectUser : null,
    name: "Not Yet Selected"
};

export default (state=InitialState, action)=>{
    switch(action.type){
            case 'FETCH_USER':
                return {...state,data:action.payload};
            case 'USER_SELECTED':
                return {...state,SelectUser:action.payload};
            case 'USER_CHANGE':
                return {...state,name:action.payload};
            default:
                return state;
    }
};

所有提到的案例都是以前执行过的。

Answer 1

我想将名称从状态数据 [] 中的对象更改为具有相同 ID 的对象中的状态名称，该 ID 已存储在 SelectUser 中

我假设您想根据某个action更改name ，为简单起见，我将其称为CHANGE_NAME 。

case 'CHANGE_NAME' return handleNameChange(state, action)

现在你只需要在数据中找到对应的对象， spread它的原始内容并覆盖name

const handlerNameChange = (state, action) =>{
    const { name } = action

    return {
        ...state,
        data : state.data.map(item =>{
            if(item.id !== state.SelectUser.id) return item
            return {
                ...item,
                name
            }
        })
    }
}

Answer 2

试试这个，

export default (state=InitialState, action)=>{
    switch(action.type){
            case 'FETCH_USER':
                return {...state,data:action.payload};
            case 'USER_SELECTED':
                return {...state,SelectUser:action.payload};
            case 'USER_CHANGE':
                return {
                         ...state,
                         name: state.data.reduce((prev, item)=>{
                                  if(state.SelectUser && state.SelectUser.some(elt=>elt.id === item.id)){
                                      return item.name;
                                  }else{
                                      return prev;
                                  }
                         }, null);
                };
            default:
                return state;
    }
};