如何使用redux工具箱修改状态

Question

数据是动态提供的，我不知道它在initialState中分配的价值。这使我出了一个我无法应付的错误。

如何在initialState?中没有对象时更新状态的对象

错误

filteringSlice.ts:12 

Uncaught TypeError: Cannot read properties of undefined (reading 'products')
    at addFilter (filteringSlice.ts:12:1)
    at createReducer.ts:280:1
    at produce (immerClass.ts:94:1)
    at createReducer.ts:279:1
    at Array.reduce (<anonymous>)
    at reducer (createReducer.ts:246:1)
    at reducer (createSlice.ts:325:1)
    at combination (redux.js:560:1)
    at k (<anonymous>:2235:16)
    at D (<anonymous>:2251:13)

呼叫动作

onChange={(selectedValue) => {
  dispatch(
    addFilter({
      products: { category__name: { filter: selectedValue } },
    })
  );
}}

切片

import { createSlice } from "@reduxjs/toolkit";
const initialState = {} as any;
const filteringSlice = createSlice({
  name: "filtering",
  initialState,
  reducers: {
    addFilter: (state, action) => {
      const key = Object.keys(action.payload)[0];
      const key2 = Object.keys(action.payload[key])[0];
      const values = Object.values(action.payload[key])[0];
      //@ts-ignore
      state.filters[key][key2] = { ...state.filters[key][key2], ...values };
    },
  },
});
const { reducer, actions } = filteringSlice;
export const { addFilter } = actions;
export default reducer;

Answer 1

因此，您的状态首先是一个空对象：

const initialState = {} as any;

但是，您的访问方式就好像它有一个更深层次的嵌套结构一样：

state.filters[key][key2] = ...

这不起作用，因为没有state['filters']，也没有state['filters']['products']等等。

您需要手动创建该嵌套的每个级别(或者为您的状态考虑一个更好、更平坦的结构)：

/*
action.payload = {
  products: {
    category__name: {
      filter: selectedValue
    }
  }
}
*/
const key = Object.keys(action.payload)[0]; // 'products'
const key2 = Object.keys(action.payload[key])[0]; // 'category__name'
const values = Object.values(action.payload[key])[0]; // selectedValue

if (!state.filters) {
  state.filters = {};
}
if (!state.filters[key]) {
  state.filters[key] = {}; 
}
if (!state.filters[key][key2]) {
    state.filters[key][key2] = {};
}

state.filters[key][key2] = { ...state.filters[key][key2], ...values };