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React/Redux中的通用还原剂/作用

redux reactjs javascript

kojow7 · 技术社区 · 6 年前

我正在尝试确定如何在同一个组件中使用多个数据段。

Cards . 所以,如果用户点击 /cards/hockey /cards/football ,它应该遵循相同的过程,检查是否存储了数据,如果没有从API中提取数据,并显示包含该数据的Cards页面。

stats 关于不同运动队的数据。

我不会总是提前知道什么类型的卡是可用的,所以我不能在我的应用程序中硬编码特定的运动类型。

所以在本例中,我只想创建两个组件:cards和stats,但需要动态加载数据来填充这些组件。

现在我有太多的重复进行,它是硬编码。这意味着,如果不创建新代码来处理这些类型中的每一个,我就不能在将来动态地添加新类型。

举个例子,现在我有了行动/足球卡片.js和/或行动/曲棍球卡片行动.js. 然后我有一个减速机/足球减速机.js和/或减速器/曲棍球减速机.js. 对于Stats组件,我可能也有类似的组件。

我还指定了状态,例如 FETCH_HOCKEY_CARDS_SUCCESS 或 FETCH_FOOTBALL_CARDS_SUCCESS .

我试图遵循的一个例子是 https://scotch.io/tutorials/bookshop-with-react-redux-ii-async-requests-with-thunks

我能做些什么使我的代码更通用,这样我就不需要硬编码特定的数据集了。有没有什么好的教程可以处理类似的情况?

进一步澄清

我的一个组件(屏幕)是运动卡屏幕。菜单系统(带链接)是从API在站点加载时自动生成的,所以我并不总是知道有哪些链接可用。所以,可能有曲棍球,足球,以及其他一些我没有想到的运动的链接。单击菜单链接时,它将调用该运动类型的API,并在运动卡屏幕上显示数据。

基于上面的链接(以及其他类似的站点),我已经在actions and reducers部分找到了如何硬编码每个特定运动的请求,但是如果我不提前了解运动,我还无法找到一般的方法。

根据目前的答复进一步澄清

如果有人在API数据库中添加了一个名为MuffiBall的新sport,我的应用程序就需要能够处理它。因此,我不能期望为每个添加到API的新运动添加新的JavaScript代码。

我当前代码的概要

索引.js

//index.js
//Other imports here (not shown)
import Cards from './components/CardsPage'
import * as cardActions from './actions/cardActions';
import * as statsActions from './actions/statsActions';

import configureStore from './store/configureStore';

const store = configureStore();

/* Bad place to put these, and currently I am expected to know what every sport is*/
store.dispatch(hockeyActions.fetchHockey());
store.dispatch(footballActions.fetchFootball());
store.dispatch(muffiballActions.fetchMuffiball());


render(
  <Provider store={store}>
          <Router>
                <div>

                    /* Navigation menu here (not shown) */
                    /* Currently it is manually coded, */
                    /* but I will be automatically generating it based on API */

                      <Route exact path="/" component={Home} />
                      <Route path="/about" component={About} />
                      <Route path="/cards/:val" component={Cards} />
                      <Route path="/stats/:val" component={Stats} />
                </div>
          </Router>
  </Provider>,
  document.getElementById('app')
);

商店/配置存储.js

// store/configureStore.js
import {createStore, compose, applyMiddleware} from 'redux';
// Import thunk middleware
import thunk from 'redux-thunk';
import rootReducer from '../reducers';

export default function configureStore(initialState) {
  return createStore(rootReducer, initialState,
    // Apply to store
    applyMiddleware(thunk)
  );
}

// actions/actionTypes

export const FETCH_HOCKEY_SUCCESS = 'FETCH_HOCKEY_SUCCESS';
export const FETCH_FOOTBALL_SUCCESS = 'FETCH_FOOTBALL_SUCCESS';
export const FETCH_MUFFIBALL_SUCCESS = 'FETCH_MUFFIBALL_SUCCESS';

行动/曲棍球动作.js(每项运动一个这样的文件-需要制作一个通用文件):

// hockeyActions.js (one such file for every sport - need to make this one generic file):

import Axios from 'axios';

const apiUrl = '/api/hockey/';
// Sync Action
export const fetchHockeySuccess = (hockey) => {
  return {
    type: 'FETCH_HOCKEY_SUCCESS',
    hockey
  }
};


//Async Action
export const fetchHockey = () => {
  // Returns a dispatcher function
  // that dispatches an action at a later time
  return (dispatch) => {
    // Returns a promise
    return Axios.get(apiUrl)
      .then(response => {
        // Dispatch another action
        // to consume data

        dispatch(fetchHockeySuccess(response.data))
      })
      .catch(error => {
        console.log(error)
        throw(error);
      });
  };
};

异径管/曲棍球减速机.js(每项运动有一个这样的文件-需要制作一个通用文件)

// reducers/hockeyReducers.js (one such file for every sport - need to make this one generic file)

import * as actionTypes from '../actions/actionTypes'

export const hockeyReducer = (state = [], action) => {
  switch (action.type) {
    case actionTypes.FETCH_HOCKEY_SUCCESS:
          return action.hockey;
    default:
          return state;
  }
};

// reducers/index.js

import { combineReducers } from 'redux';
import {hockeyReducer} from './hockeyReducers'
import {footballReducer} from './footballReducers'
import {muffiballReducer} from './muffiballReducers'

export default combineReducers({
  hockey: hockeyReducer,
  football: footballReducer,
  muffiball: muffiballReducer,
  // More reducers for each sport here
});

组件/卡片页.js:

//components/CardsPage.js

import React from 'react';
import { connect } from 'react-redux';

class Cards extends React.Component{
  constructor(props){
    super(props);

    this.state = {
        data: this.props.data,
    }

  }

  componentWillReceiveProps(nextProps){
        this.setState({
                data: nextProps.data,
        })
  }

  render(){

    return(
        {/* cards displayed from this.state.data */}
    )
  }
}

const mapStateToProps = (state, ownProps) => {
  return {
    data: state[ownProps.match.params.val]
  }
};

export default connect(mapStateToProps)(Cards);

4 回复 | 直到 6 年前

lecstor 6 年前

退一步,找出具有独特形状的数据类型,例如 cards 和 stats 如

export const fetchCards = (sport) => {
  return (dispatch) => {
    return Axios.get(`/api/${sport}/`)
      .then(response =>
        dispatch(fetchCardSuccess({ sport, data: response.data }))
      )
      .catch(error => {
        console.log(error)
        throw(error);
      });
  };
};

减速机

export const cardReducer = (state = {}, action) => {
  switch (action.type) {
    case actionTypes.FETCH_CARD_SUCCESS:
      return { ...state, [action.sport]: action.data };
    default:
      return state;
  }
};

卡片选择器

export const getSport(state, sport) {
  return state.cards[sport];
}

pizzarob 6 年前

你可以买个普通的 <Results /> 组件。不确定如何进行路由,但可以使用URL的路径名来确定要获取和显示的数据。

路由组件(React Router 4)可以如下所示:

<Route path="/cards/:id" render={props => <Results {...props} />}

然后在你的 <Results/> 可以使用的组件 react-redux componentDidMount 你可以看看你有没有合适的数据。如果您没有合适的数据,那么从componentDidMount发送一个操作来获取它。像这样的

import { connect } from 'react-redux';
import React from 'react';
import { fetchDataAction } from './actions';

class Results extends React.Component {
  componentDidMount() {
    // check if results exists, if not then fire off an action to get 
    // data. Use whatever async redux pattern you want
    if (!this.props.results) {
      this.props.fetchData();
    }
  }

  render() { /* DO SOMETHING WITH RESULTS, OR LACK OF */ }
}

const mapStateToProps = (state, ownProps) => ({
  results: state.results[ownProps.match.params.id],
});

const mapDispatchToProps = (dispatch, ownProps) => ({
  fetchData() {
    // send path parameter via action to kick off async fetch
    dispatch(fetchDataAction(ownProps.match.params.id));
  },
});

export default connect(mapStateToProps, mapDispatchToProps)(Results);

您可以有一个结果缩减器,它只是一个将类别映射到结果的对象。结果如下:

export default (state = {}, action) => {
  switch(action.type) {
    case 'FETCH_LOADED':
      const { payload: { type, results } } = action;
      return {
        ...state,
        [type]: results,
      };
    default:
      return state;
  };
};

Cody S 6 年前

Redux Ducks . 这里有一个 good helper library and example 在你的代码库中实现这个。

以上面链接中的示例为基础,您可以看到:

// remoteObjDuck.js

import Duck from 'extensible-duck'
import axios from 'axios'

export default function createDuck({ namespace, store, path, initialState={} }) {
  return new Duck({
    namespace, store,

    consts: { statuses: [ 'NEW', 'LOADING', 'READY', 'SAVING', 'SAVED' ] },

    types: [
      'UPDATE',
      'FETCH', 'FETCH_PENDING',  'FETCH_FULFILLED',
      'POST',  'POST_PENDING',   'POST_FULFILLED',
    ],

    reducer: (state, action, { types, statuses, initialState }) => {
      switch(action.type) {
        case types.UPDATE:
          return { ...state, obj: { ...state.obj, ...action.payload } }
        case types.FETCH_PENDING:
          return { ...state, status: statuses.LOADING }
        case types.FETCH_FULFILLED:
          return { ...state, obj: action.payload.data, status: statuses.READY }
        case types.POST_PENDING:
        case types.PATCH_PENDING:
          return { ...state, status: statuses.SAVING }
        case types.POST_FULFILLED:
        case types.PATCH_FULFILLED:
          return { ...state, status: statuses.SAVED }
        default:
          return state
      }
    },

    creators: ({ types }) => ({
      update: (fields) => ({ type: types.UPDATE, payload: fields }),
      get:        (id) => ({ type: types.FETCH, payload: axios.get(`${path}/${id}`),
      post:         () => ({ type: types.POST, payload: axios.post(path, obj) }),
      patch:        () => ({ type: types.PATCH, payload: axios.patch(`${path}/${id}`, obj) })
    }),

    initialState: ({ statuses }) => ({ obj: initialState || {}, status: statuses.NEW, entities: [] })
  })
}

每一项运动都会创造一只鸭子,重复使用相同的功能。

曲棍球:

// hockeyDuck.js

import createDuck from './remoteObjDuck'

export default createDuck({ namespace: 'my-app', store: 'hockeyCards', path: '/cards/hockey' })

// footballDuck.js

    import createDuck from './remoteObjDuck'

    export default createDuck({ namespace: 'my-app', store: 'footballCards', path: '/cards/football' })

// 异径管.js

import { combineReducers } from 'redux'
import footballDuck from './footballDuck'
import hockeyDuck from './hockeyDuck'

export default combineReducers({ [footballDuck.store]: footballDuck.reducer, [hockeyDuck.store]: hockeyDuck.reducer })

如果您想动态地向redux添加reducer,您必须使用以下方法: https://github.com/ioof-holdings/redux-dynamic-reducer . 然后可以根据API调用响应动态创建duck:

//get from API
var sport = "football";
var footballDuck = createDuck({ namespace: 'my-app', store: 'cards', path: `/cards/${sport}` });
store.attachReducer({ [footballDuck.store]: footballDuck.reducer });

-2

Estefano Timoteo 6 年前

// structure (something like...)

/*
./components 
./redux
./redux/actions
./redux/reducers
./redux/sagas
./redux/types
./util
*/

/* ------------------------------------------------- */

/* package.json */

{
  (...)
  "proxy": "http://localhost:3000",
  (...)  
}

/* ------------------------------------------------- */

/* index.js or otherComponent.js */

import React from 'react' 
import { render } from 'react-dom'
import { createStore, applyMiddleware } from 'redux'
import { Provider } from 'react-redux'
import reducers from './redux/reducers/index'
import logger from 'redux-logger'
import createSagaMiddleware from 'redux-saga'
import indexSagas from './redux/sagas/indexSagas'

import { environment } from './util/baseUrl'

const sagaMiddleware = createSagaMiddleware()

const store = 
  environment === 'DEV' ?
    createStore(
      reducers,
      window.__REDUX_DEVTOOLS_EXTENSION__ && 
      window.__REDUX_DEVTOOLS_EXTENSION__(),  
      applyMiddleware(sagaMiddleware, logger)
    ) :
    createStore(
      reducers,
      applyMiddleware(sagaMiddleware)
    ) 

sagaMiddleware.run(indexSagas)

render(
   <Provider store={store}>
      <App />      
   </Provider>,
 document.getElementById('app'))


/* ------------------------------------------------- */

/* baseURL.js */

const DEV = 'DEV'
const PROD = 'PROD'

/*-----------------------------------------*/
/*------*/ export const environment = DEV /* <------- */
/*-----------------------------------------*/

export const baseURL = 
    environment === DEV ?
    '/api/v1/' : 
    'https://abcde.website.net/api/v1/' 

/* ------------------------------------------------- */

/* genericTypes.js */

export const GET_REGISTERS_REQUEST = 'GET_REGISTERS_REQUEST'
export const GET_REGISTERS_SUCCESS = 'GET_REGISTERS_SUCCESS'
export const GENERIC_ERROR_MSG = 'GENERIC_ERROR_MSG'

/* ------------------------------------------------- */

/* actions.js */

export const getRegistersRequest = ( route ) => {
  return {
    type: GET_REGISTERS_REQUEST,
    route,
  }
}
export const getRegistersSuccess = ( data ) => {
  return {
    type: GET_REGISTERS_SUCCESS,
    data,
  }
} 
export const genericErrorMsg = ( errorMsg ) => {
  return {
    type: GENERIC_ERROR_MSG,
    errorMsg,
  }
}

/* ------------------------------------------------- */

/* genericReducer.js */

import { GET_REGISTERS_REQUEST, GET_REGISTERS_SUCCESS, GENERIC_ERROR_MSG } from '../types/genericTypes'

const INITIAL_STATE = {
  data: [],
  isFetching: false,
  isLoaded: false,
  error: false,
  errorMsg: '',
}

const genericReducer = (state = INITIAL_STATE, action) => {
  switch(action.type){
    case GET_REGISTERS_REQUEST:
      return {
        ...state,
        data: [],
        isFetching: true,
        isLoaded: false,
        error: false,
        errorMsg: '',
      }  
    case GET_REGISTERS_SUCCESS:
      return {
        ...state,
        data: action.data,
        isFetching: false,
        isLoaded: true,
      }
    case GENERIC_ERROR_MSG: 
      return {
        ...state,
        isFetching: false,
        error: true,
        errorMsg: action.errorMsg,
      }   
    default:
      return state
  }
}
export default genericReducer  

/* ------------------------------------------------- */

/* yourComponent.js  */

import React, { Component } from "react"
import { connect } from 'react-redux'
import { getRegistersRequest } from '../../redux/actions'   

//(...)
// this.props.getRegistersRequest('cards/hockey')
// this.props.getRegistersRequest('cards/football')
//(...)

const mapStateToProps = (state) => {
  return {
    data: state.genericReducer.data,
    isFetching: state.genericReducer.isFetching,
    isLoaded: state.genericReducer.isLoaded,
    error: state.genericReducer.error,
    errorMsg: state.genericReducer.errorMsg,
  } 
}
const mapDispatchToProps = (dispatch) => {
  return {
    getRegistersRequest: ( route ) => dispatch(getRegistersRequest( route )),
  }
}
export default connect(mapStateToProps, mapDispatchToProps)(yourComponent)

/* ------------------------------------------------- */

/* indexSagas.js */

import { takeLatest } from 'redux-saga/effects'
import axios from 'axios'

import { GET_REGISTERS_REQUEST } from '../types/genericTypes'
import { getRegistersRequest } from './genericSagas'

function* indexSagas() {
  try {
    yield (takeLatest(GET_REGISTERS_REQUEST, getRegistersRequest, axios))  
  }
  catch (e) {
    // (...)
  }
}
export default indexSagas  

/* ------------------------------------------------- */

/* genericSagas.js */

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

import { getRegistersSuccess, genericErrorMsg } from '../actions'

export function* getRegistrosRequest(axios, action) {
  const rest = createRest(axios)
  try {
    let route = ''
    switch (action.route) {
      case 'cards/hockey':
      case 'cards/football':
        route = action.route
        break
      default: {
        yield put(genericErrorMsg('Route [ ' + action.route + ' ] not implemented yet!'))
        return
      }
    }    
    const data = yield rest.get(route)
    yield put(getRegistersSuccess(data))
  }
  catch (e) {
    yield put(genericErrorMsg(e))
  }
}

/* ------------------------------------------------- */

/* createRest */

import { baseURL } from '../../util/baseUrl'
function createRest(axios){
  const token = localStorage.getItem('yourToken')
  const rest = axios.create({
    baseURL: baseURL,
    headers:{
      Authorization: 'Bearer ' + token
    }
  })
  return rest  
}
export default createRest

/* ------------------------------------------------- */

希望有帮助!