[Front-end knowledge] React foundation consolidation (36) - asynchronous operation in RTK

React foundation consolidation (36) - asynchronous operations in RTK

1. Using asynchronous operations in RTK

1. Introduce createAsyncThunk in RTK to monitor execution status in extraReducers

   import {
         
          createSlice, createAsyncThunk } from "@reduxjs/toolkit";
   import axios from "axios";
   
   export const fetchHomeMultidataAction = createAsyncThunk(
     "fetch/homemultidata",
     async () => {
         
         
       const res = await axios.get("http://123.207.32.32:8000/home/multidata");
       return res.data;
     }
   );
   
   const homeSlice = createSlice({
         
         
     name: "home",
     initialState: {
         
         
       banners: [],
       recommends: [],
     },
     reducers: {
         
         
       changeBanners(state, {
          
           payload }) {
         
         
         state.banners = payload;
       },
       changeRecommends(state, {
          
           payload }) {
         
         
         state.recommends = payload;
       },
     },
     extraReducers: {
         
         
       [fetchHomeMultidataAction.pending](state, action) {
         
         
         console.log("fetchHomeMultidataAction pending");
       },
       [fetchHomeMultidataAction.fulfilled](state, {
          
           payload }) {
         
         
         console.log("fetchHomeMultidataAction fulfilled");
         state.banners = payload.data.banner.list;
         state.recommends = payload.data.recommend.list;
       },
       [fetchHomeMultidataAction.rejected](state, action) {
         
         
         console.log("fetchHomeMultidataAction rejected");
       },
     },
   });
   
   export const {
         
          changeBanners, changeRecommends } = homeSlice.actions;
   export default homeSlice.reducer;
   
   

2. Introduce the required asynchronous operation Action in the interface

   import React, {
         
          PureComponent } from "react";
   import {
         
          connect } from "react-redux";
   import {
         
          addNumber } from "../store/features/counter";
   import {
         
          fetchHomeMultidataAction } from "../store/features/home";
   
   export class Home extends PureComponent {
         
         
     componentDidMount() {
         
         
       this.props.fetchHomeMultidata()
     }
   
     addNumber(num) {
         
         
       this.props.addNumber(num);
     }
   
     render() {
         
         
       const {
         
          counter } = this.props;
       return (
         <div>
         home:{
         
         counter}
     <button onClick={
         
         (e) => this.addNumber(5)}>+5</button>
   <button onClick={
         
         (e) => this.addNumber(8)}>+8</button>
   <button onClick={
         
         (e) => this.addNumber(18)}>+18</button>
   </div>
   );
   }
   }
   
   const mapStateToProps = (state) => ({
         
         
     counter: state.counter.counter,
   });
   
   const mapDispatchToProps = (dispatch) => ({
         
         
     addNumber(num) {
         
         
       dispatch(addNumber(num));
     },
     fetchHomeMultidata(){
         
         
       dispatch(fetchHomeMultidataAction())
     }
   });
   
   export default connect(mapStateToProps, mapDispatchToProps)(Home);
   
   

3. View running results
   

2. Another way of writing extraReducer (chain call)

1. extraReducer can also pass in a function that accepts a builder parameter:

extraReducers: (builder) => {
    
    
  builder
    .addCase(fetchHomeMultidataAction.pending, (state, action) => {
    
    
    console.log("fetchHomeMultidataAction pending");
  })
    .addCase(fetchHomeMultidataAction.fulfilled, (state, {
     
      payload }) => {
    
    
    console.log("fetchHomeMultidataAction fulfilled");
    state.banners = payload.data.banner.list;
    state.recommends = payload.data.recommend.list;
  })
    .addCase(fetchHomeMultidataAction.rejected, (state, action) => {
    
    
    console.log("fetchHomeMultidataAction rejected");
  });
},

2. View the running results, which are consistent with the previous writing results