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问如何使用节点服务器端的redux-thunk？
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Stack Overflow用户

提问于 2020-02-23 06:39:15

回答 1查看 678关注 0票数 0

(代码来自https://redux.js.org/advanced/async-actions)

代码设置一个redux存储，然后通过一些操作调用存储上的调度。商店使用redux-thunk来管理异步API调用。

这是index.js

    import reduxThunk from 'redux-thunk'
    const { thunkMiddleware } = reduxThunk;
    import redux from 'redux';
    const { createStore } = redux;
    const { applyMiddleware } = redux;
    import { selectSubreddit, fetchPosts } from './actions.js'

    import rootReducer from './reducers.js'

    const store = createStore(
      rootReducer,
      applyMiddleware(thunkMiddleware)
    );

    store.dispatch(selectSubreddit('reactjs'));
    store.dispatch(fetchPosts('reactjs')).then(() => console.log(store.getState()));

运行node index.js后出错

    (node:19229) ExperimentalWarning: The ESM module loader is experimental.
    applyMiddleware [Function: applyMiddleware]
    /home/code/redux/tutorial_async_actions/node_modules/redux/lib/redux.js:648
            return middleware(middlewareAPI);
                  ^
    TypeError: middleware is not a function
        at /home/code/redux/tutorial_async_actions/node_modules/redux/lib/redux.js:648:16
        at Array.map (<anonymous>)
        at /home/code/redux/tutorial_async_actions/node_modules/redux/lib/redux.js:647:31
        at createStore (/home/code/redux/tutorial_async_actions/node_modules/redux/lib/redux.js:85:33)
        at file:///home/code/redux/tutorial_async_actions/index.js:18:15
        at ModuleJob.run (internal/modules/esm/module_job.js:110:37)
        at async Loader.import (internal/modules/esm/loader.js:164:24)

，我该怎么做才能让它运行呢？，我认为这与ES6和模块有关，但我被困住了……:(

我已经在这么做了(正如这个答案所建议的)

import redux from 'redux';
const { createStore, applyMiddleware } = redux;

(我可以用创建-反应-应用程序让这个工作.但我更愿意在没有webpack等人的情况下完成这项工作。

下面是供参考的剩余代码。

在这里的行动

    export const SELECT_SUBREDDIT = 'SELECT_SUBREDDIT'
    export function selectSubreddit(subreddit) {
      return {
        type: SELECT_SUBREDDIT,
        subreddit
      };
    }

    export const INVALIDATE_SUBREDDIT = 'INVALIDATE_SUBREDDIT'
    function invalidateSubreddit(subreddit) {
      return {
        type: INVALIDATE_SUBREDDIT,
        subreddit
      };
    }

    export const REQUEST_POSTS = 'REQUEST_POSTS'
    function requestPosts(subreddit) {
      return {
        type: REQUEST_POSTS,
        subreddit
      }
    }

    export const RECEIVE_POSTS = 'RECEIVE_POSTS'
    function receivePosts(subreddit, json) {
      return {
        type: RECEIVE_POSTS,
        subreddit,
        posts: json.data.children.map(child => child.data),
        receivedAt: Date.now()
      }
    }

    export function fetchPosts(subreddit) {
      return function (dispatch) {
        dispatch(requestPosts(subreddit));

        return fetch(`https://www.reddit.com/r/${subreddit}.json`)
          .then(
            response => response.json(),
            error => console.log('An error occurred.', error)
          )
          .then(json =>
            dispatch(receivePosts(subreddit, json))
          )
      }
    }

这里是减速机

    import redux from 'redux';
    const { combineReducers } = redux;
    import {
      SELECT_SUBREDDIT,
      INVALIDATE_SUBREDDIT,
      REQUEST_POSTS,
      RECEIVE_POSTS
    } from './actions.js';

    function selectedSubreddit(state = 'reactjs', action) {
      switch (action.type) {
        case SELECT_SUBREDDIT:
          return action.subreddit
        default:
          return state
      }
    }

    function posts(
      state = {
        isFetching: false,
        didInvalidate: false,
        items: []
      },
      action
    ) {
      switch (action.type) {
        case INVALIDATE_SUBREDDIT:
          return Object.assign({}, state, { didInvalidate: true })
        case REQUEST_POSTS:
          return Object.assign({}, state, { isFetching: true, didInvalidate: false });
        case RECEIVE_POSTS:
          return Object.assign({}, state, {
            isFetching: false, didInvalidate: false,
            items: action.posts,
            lastUpdated: action.receivedAt
          });
        default:
          return state;

      }
    }

    function postsBySubreddit(state = {}, action) {
      switch (action.type) {
        case INVALIDATE_SUBREDDIT:
        case RECEIVE_POSTS:
        case REQUEST_POSTS:
          return Object.assign({}, state, {
            [action.subreddit]: posts(state[action.subreddit], action)
          });
        default:
          return state
      }

    }

    const rootReducer = combineReducers({
      postsBySubreddit,
      selectedSubreddit
    });

    export default rootReducer;

在这里package.json

    {
      "name": "redux_async_actions",
      "version": "1.0.0",
      "description": "",
      "main": "index.js",
      "scripts": {
        "test": "echo \"Error: no test specified\" && exit 1"
      },
      "author": "",
      "license": "ISC",
      "type": "module",
      "dependencies": {
        "redux": "^4.0.5",
        "redux-thunk": "^2.3.0"
      }
    }

node.js

redux

redux-thunk

es6-modules

回答 1

Stack Overflow用户

回答已采纳

发布于 2020-02-24 04:32:31

(我最初问的是这个问题，但我的登录失败了)

我使用节点模块系统 (即使用所需的函数)来完成这个任务。ES6导出/导入应该可以工作，但我想我尝试使用的模块(redux、redux)中的一个模块与ES6导出/导入操作不太好。

本质上，我将export语句转换为exports.语句

export function(...) {...} => exports.myFunction = function(...) {...}

我将import语句转换为require语句。

import {myFunction} from './somefile.js'=> const module = require('./somefile.js')

在下面的代码中，如问题中所示，但使用了require。

index.js

    const redux = require('redux');
    const { createStore, applyMiddleware } = redux;

    const ReduxThunk = require('redux-thunk').default

    const actions = require('./actions.js');
    const { selectSubreddit, fetchPosts } = actions;

    const rootReducer = require('./reducers.js');

    const store = createStore(
      rootReducer.rootReducer,
      applyMiddleware(ReduxThunk)
    );

    store.dispatch(selectSubreddit('reactjs'));
    store.dispatch(fetchPosts('reactjs')).then(() => console.log(store.getState()));

actions.js

    const fetch = require('cross-fetch');

    const SELECT_SUBREDDIT = 'SELECT_SUBREDDIT'
    exports.SELECT_SUBREDDIT = SELECT_SUBREDDIT
    function selectSubreddit(subreddit) {
      return {
        type: SELECT_SUBREDDIT,
        subreddit
      };
    }
    exports.selectSubreddit = selectSubreddit;

    const INVALIDATE_SUBREDDIT = 'INVALIDATE_SUBREDDIT'
    exports.INVALIDATE_SUBREDDIT = INVALIDATE_SUBREDDIT
    function invalidateSubreddit(subreddit) {
      return {
        type: INVALIDATE_SUBREDDIT,
        subreddit
      };
    }

    const REQUEST_POSTS = 'REQUEST_POSTS'
    exports.REQUEST_POSTS = REQUEST_POSTS
    function requestPosts(subreddit) {
      return {
        type: REQUEST_POSTS,
        subreddit
      }
    }

    const RECEIVE_POSTS = 'RECEIVE_POSTS'
    exports.RECEIVE_POSTS = RECEIVE_POSTS
    function receivePosts(subreddit, json) {
      return {
        type: RECEIVE_POSTS,
        subreddit,
        posts: json.data.children.map(child => child.data),
        receivedAt: Date.now()
      }
    }

    function fetchPosts(subreddit) {
      return function (dispatch) {
        dispatch(requestPosts(subreddit));

        return fetch(`https://www.reddit.com/r/${subreddit}.json`)
          .then(
            response => response.json(),
            error => console.log('An error occurred.', error)
          )
          .then(json =>
            dispatch(receivePosts(subreddit, json))
          )
      }
    }
    exports.fetchPosts = fetchPosts;

reducers.js

    const redux = require('redux');
    const { combineReducers } = redux;
    const actions = require('./actions.js');
    const {
      SELECT_SUBREDDIT,
      INVALIDATE_SUBREDDIT,
      REQUEST_POSTS,
      RECEIVE_POSTS
    } = actions;

    function selectedSubreddit(state = 'reactjs', action) {
      switch (action.type) {
        case SELECT_SUBREDDIT:
          return action.subreddit
        default:
          return state
      }
    }

    function posts(
      state = {
        isFetching: false,
        didInvalidate: false,
        items: []
      },
      action
    ) {
      switch (action.type) {
        case INVALIDATE_SUBREDDIT:
          return Object.assign({}, state, { didInvalidate: true })
        case REQUEST_POSTS:
          return Object.assign({}, state, { isFetching: true, didInvalidate: false });
        case RECEIVE_POSTS:
          return Object.assign({}, state, {
            isFetching: false, didInvalidate: false,
            items: action.posts,
            lastUpdated: action.receivedAt
          });
        default:
          return state;

      }
    }

    function postsBySubreddit(state = {}, action) {
      switch (action.type) {
        case INVALIDATE_SUBREDDIT:
        case RECEIVE_POSTS:
        case REQUEST_POSTS:
          return Object.assign({}, state, {
            [action.subreddit]: posts(state[action.subreddit], action)
          });
        default:
          return state
      }

    }

    const rootReducer = combineReducers({
      postsBySubreddit,
      selectedSubreddit
    });

    exports.rootReducer = rootReducer;

package.json (通知包没有"type": "module",)

    {
      "name": "basic_example_only_node",
      "version": "1.0.0",
      "description": "",
      "main": "index.js",
      "scripts": {
        "test": "echo \"Error: no test specified\" && exit 1"
      },
      "author": "",
      "license": "ISC",
      "dependencies": {
        "cross-fetch": "^3.0.4",
        "redux": "^4.0.5",
        "redux-thunk": "^2.3.0"
      }
    }

票数 0

页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持

原文链接：

https://stackoverflow.com/questions/60363308

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