如何使用Redux从服务器获取数据？

Question

我需要借助Redux之类的工具从服务器获取数据。我看了一些有关它的教程，并为此编写了一些代码。这里是：

actions / fetching_actions.js

import * as Actions from '../constants/action_types';

function fetchListOfCities() {
  return fetch(`${Actions.BASE_URL}/data/2.5/find?lat=55.5&lon=37.5&cnt=10&appid=8df903ce56f6d18245e72f380beb297d`);
}

export const listOfCitiesRequest = () => function (dispatch) {
  return fetchListOfCities()
    .then(list => list.json())
    .then((list) => {
      dispatch(getListOfCities(list));
    }).catch((error) => {
      console.log(error);
    });
};

export const getListOfCities = result => ({
  type: Actions.LIST_RESPONSE,
  result,
});

常量/action_types.js

export const BASE_URL = 'http://api.openweathermap.org';

export const LIST_RESPONSE = 'LIST_RESPONSE';

export const CITY_RESPONSE = 'CITY_RESPONSE';

reducers / fetching_reducer.js

import * as Actions from '../constants/action_types';

const initialState = {
  list: [],
  city: {},
};

const FETCHING_REDUCER = (state = initialState, action) => {
  switch (action.type) {
    case Actions.LIST_RESPONSE:
      return {
        ...state,
        list: action.result,
      };
    case Actions.CITY_RESPONSE:
      return {
        ...state,
        city: action.result,
      };
    default:
      return state;
  }
};

export default FETCHING_REDUCER;

reducers / index.js

import * as Actions from '../constants/action_types';

const initialState = {
  list: [],
  city: {},
};

const FETCHING_REDUCER = (state = initialState, action) => {
  switch (action.type) {
    case Actions.LIST_RESPONSE:
      return {
        ...state,
        list: action.result,
      };
    case Actions.CITY_RESPONSE:
      return {
        ...state,
        city: action.result,
      };
    default:
      return state;
  }
};

export default FETCHING_REDUCER;

不幸的是，我不知道该怎么做。在组件中以这种方式获取数据之前：

getCitiesListFromApiAsync = async () => {
     const fetchData = await fetch('http://api.openweathermap.org/data/2.5/find?lat=55.5&lon=37.5&cnt=10&appid=8df903ce56f6d18245e72f380beb297d').then();
     const data = await fetchData.json();

     if (data.cod !== '200') {
       Alert.alert('Loading failed');
     } else {
       this.setState({ data });
     }
   };

但是我听说最好通过redux来获取数据，所以，请您能解释一下如何完成此获取部分，我应该在这里添加什么？

Answer 1

在佐贺中，请导入这些东西

import {  put } from 'redux-saga/effects';

getCitiesListFromApiAsync = async () => {
     const fetchData = await fetch('http://api.openweathermap.org/data/2.5/find?lat=55.5&lon=37.5&cnt=10&appid=8df903ce56f6d18245e72f380beb297d').then();
     const data = await fetchData.json();

     if (data.cod !== '200') {
       Alert.alert('Loading failed');
     } else {
       yield put({ type: LIST_RESPONSE, payload: data });
     }
   };

在减速器中

  switch (action.type) {
    case Actions.LIST_RESPONSE:
      return {
        ...state,
        list: action.payload,
      };