记录一篇关于redux-saga的基本使用过程

安装

npm install --save redux
npm install --save redux-saga

配置action

actionType

创建文件src/actions/types.js，在types.js文件中添加需要的action类型

export const TEST1_ACTION = 'test1';
export const SET_TEST2_ACTION = 'change_test2';
export const SET_TEST3_ACTION = 'change_test3';

createActions

创建文件src/actions/test.js，在test.js文件中编写action

import {TEST1_ACTION, SET_TEST2_ACTION, SET_TEST3_ACTION} from './types

// 获取test1的值
export const getTest1Action = () => {
  return {
    type:TEST1_ACTION
  }
}

// 写入test2的值
export const setTest2Action = (testValue) => {
  return {
    type:SET_TEST2_ACTION,
    payload:testValue
  }
}

// 写入test3的值
export const setTest3Action = (payload) => {
  return {
    type:SET_TEST3_ACTION,
    payload
  }
}

配置reducer

因为一个项目中可能会有很多地方需要用到reducer，所以把这些reducer文件分开管理比较好，比如：test.js,settings.js,auth.js等等。

创建文件src/reducers/test.js，编写test reducer

import {TEST1_ACTION, SET_TEST2_ACTION, SET_TEST3_ACTION} from '../actions/types

// 初始化
const initTest = {
  test1:'这是test1初始化的值',
  test2:'这是test2初始化的值',
  test3:'这是test3初始化的值'
}

export default (state = initTest, action) =>{
  switch (action.type) {
    case TEST1_ACTION:{
      return {
        ...state
      }
    }
    case SET_TEST2_ACTION:{
      return {
        ...state,
        test2:action.payload
      }
    }
    case SET_TEST3_ACTION:{
      return {
        ...state,
        test3:action.payload.testValue
      }
    }
    default:
    return state
  }
}

创建文件src/reducers/index.js

import {combineReducers} from 'redux'
import test from './test'


const reducers = combineReducers({
  test,
  /*
  还可以继续加入其它的reducer文件，比如：
  settings,
  auth,
  */
});

export default reducers;

配置saga

创建文件src/sagas/test.js

import {all,fork,put,takeEvery} from 'redux-saga/effects'
import {setTest2Action, setTest3Action} from "../actions/test"
import {SET_TEST2_ACTION, SET_TEST3_ACTION} from "../actions/actionTypes"
import axios from 'axios'

function* changeTest2 (testValue) {
  yield put(setTest2Action(testValue))
}

function* changeTest3 (obj) {
  try{
    // 这里使用axios从网络获取数据演示，没有安装axios的需要先安装它。
    // 期间响应状态码判断就省略了，就当它每次请求都成功获得testValue的数据
    response = axios.get('http://localhost/api/test')
    
    // 假设response.data里面有一个key为testValue的值
    yield put(setTest3Action(response.data))
  } catch (error) {
    console.error('这里也可以yield put一个createAction，这里不作演示')
  }
}

export function* setTest2 () {
  yield takeEvery(SET_TEST2_ACTION, changeTest2)
}

export function* setTest3 () {
  yield takeEvery(SET_TEST3_ACTION, changeTest3)
}

export default function* testSaga(){
  yield all([
    fork(setTest2),
    fork(setTest3),
  ])
}

创建文件src/sagas/index.js

import {all} from 'redux-saga/effects';
import testSaga from './test'

export default function* rootSaga() {
  yield all([
    testSaga()
  ]);
}

配置store

import {applyMiddleware, compose, createStore} from 'redux';
import reducers from '../reducers/index';
import createSagaMiddleware from 'redux-saga';
import rootSaga from '../sagas/index';


const sagaMiddleware = createSagaMiddleware();

// 使用数组是为了方便以后继续添加中间件
const middlewares = [sagaMiddleware];

const composeEnhancers = window.__REDUX_DEVTOOLS_EXTENSION_COMPOSE__ || compose;
const store = createStore(
 reducers,
 composeEnhancers(applyMiddleware(...middlewares))
);

sagaMiddleware.run(rootSaga);

export default store;

App入口文件路由配置

import React from 'react'
import {Provider} from 'react-redux'
import store from './store'
import Test from './Test/'
import {BrowserRouter, Route, Switch} from "react-router-dom"

const MainApp = () =>
 <Provider store={store}>
  <BrowserRouter>
   <Switch>
    <Route path="/" component={Test}/>
   </Switch>
  </BrowserRouter>
 </Provider>;

export default MainApp

Test.js

src/Test/index.js

import React from 'react'
import {connect} from 'react-redux'
import {setTest2Action, setTest3Action} from '../actions/test'

class Test extends React.Component {
  render() {

    const {test1, test2, test3, setTest2Action, setTest3Action} = this.props

    return {
      <div>
        <div>
          test1的值为：{test1}
        </div>
        <div>
          test2的值为：{test2}
          <button onClick={setTest2Action('abc')}>设置test2的值为 abc</button>
        </div>
        <div>
          test3的值为：{test3}
          <button onClick={setTest3Action()}>从网络获取test3的值</button>
        </div>
      </div>
    }
  }
}

const mapStateToProps = ({test}) => {
  const {test1,test2,test3} = test;
  return {test1,test2,test3}
}

export default connect (mapStateToProps,{setTest2Action, setTest3Action})(Test)

至此，即可运行 npm start进行测试了

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持呐喊教程。

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