如何在任何调度操作上运行 redux-saga 中间件?

Question

我在"usersaga.js中定义了以下 redux saga 中间件函数

import {call, put, takeEvery, takeLatest} from "redux-saga/effects";
import {REQUEST_API_DATA, receiveApiData} from '../store/actions';
import userServiceObject from '../services/user.service';

// Worker Saga function will be fired on USER_FETCH_ACTIONS
export function* getApiData(action){
console.log(action)
try{
// Do Api Call
const data = yield call(userServiceObject.getUsers);
console.log(data.data);
yield put(receiveApiData(data.data));
}
catch(error){
console.log("this is error part and executing");
console.log(error);
}
}

在"index.js"文件中，我使用"run"方法运行上面的函数getApiData

import React from 'react';
import ReactDOM from 'react-dom';
import {createStore, combineReducers, applyMiddleware } from 'redux';
import {Provider} from 'react-redux';
import './index.css';
import App from './App';
import * as serviceWorker from './serviceWorker';
import contactReducer from './store/reducers/userlist';
// For Creating Saga and connecting store to saga middleware
import createSagaMiddleware from 'redux-saga';
import {getApiData} from './sagas/usersaga';
const sagaMiddleware = createSagaMiddleware();
const rootReducer = combineReducers({
res: contactReducer
})
const store = createStore(rootReducer, applyMiddleware(sagaMiddleware));
sagaMiddleware.run(getApiData);
ReactDOM.render(<Provider store={store}> <App /> </Provider>, document.getElementById('root'));

serviceWorker.unregister();

它成功地从 api 获取数据，我成功地处理了由"接收ApiData"动作生成器函数生成的行动中的数据。
我想在由调度的函数"requestApiData"生成的操作上调用getApiData函数。操作名称为"{类型：REQUEST_API_DATA}"
如何在调度的操作上运行我们的 getApiData。 我的用户列表化简器文件如下所示

import * as actionTypes from "../actions";
const initialState = {
value: '',
results: []
};
const reducer = (state = initialState, action) => {
switch(action.type){
case actionTypes.STORE_CONTACTS:   // This is for storing all contacts in the state here
console.log(action.values)
return {
...state,
results: action.values
}
case actionTypes.RECEIVE_API_DATA:  
console.log(action);
return{
...state,
results: action.contacts
}
case actionTypes.DELETE_CONTACT:
return {
...state,
results: action.value
}
case actionTypes.ADD_CONTACT:
// perform add action to the database, update state and return All new data
return {
...state,
}
case actionTypes.EDIT_CONTACT:
return {
...state,
}
default:
return state;
}
};
export default reducer;

Answer 1

您需要使用实际上已经在usersaga中导入的takeEvery效果.js

所以在用户aga中.js添加这个传奇：

export function* requestWatcher(action){
yield takeEvery('REQUEST_API_DATA', getApiData);
}

在索引中.js运行此 saga 而不是直接运行getApiData：

sagaMiddleware.run(requestWatcher);

这是redux-saga的基本概念之一，我真的建议阅读文档 https://redux-saga.js.org/docs/basics/UsingSagaHelpers.html