reactjs - "Uncaught TypeError: Cannot read property ' 类型 ' of undefined"并不清楚它与什么相关

Question

我最初认为这是 react-redux、axios、lodash 和/或 react-dropzone< 的问题;但是，文件上传正常，但仍然会触发此错误。 (即使在控制台中显示“失败”，文件也会被发布到服务器)。

根据我在这里读到的内容，我开始认为该问题可能与 react-router-redux 有关:

https://github.com/reactjs/react-router-redux/issues/182

但是，这些建议对我不起作用。

无论如何，我收到一个未捕获的类型错误:无法读取未定义的属性“类型”，我无法真正判断是什么原因导致它或如何解决它。以下是一些错误的屏幕截图:

所以这里是与 react-router 相关的内容。只是不确定发生了什么。

入口点:

// ./react/index.js
import React from 'react';
import ReactDOM from 'react-dom';
import { Provider } from 'react-redux';
import { createStore, applyMiddleware, compose } from 'redux';
import thunk from 'redux-thunk';
import { BrowserRouter, Switch, Route } from 'react-router-dom';
import { routerMiddleware, ConnectedRouter } from 'react-router-redux';

import createHistory from 'history/createBrowserHistory';

// Render on every route
import App from './components/app';
import Navbar from './containers/global/navbar';
import Footer from './containers/global/footer';

// Reducers 
import rootReducer from './reducers';

// SCSS for the project
import styles from '../assets/scss/main.scss';

// IE polyfill error fix
require('es6-promise').polyfill();
var axios = require('axios');

const history = createHistory();

const initialState = {};
const enhancers = [];
const middleware = [thunk, routerMiddleware(history)];

if (process.env.NODE_ENV === 'development') {
    const devToolsExtension = window.devToolsExtension

    if (typeof devToolsExtension === 'function') {
        enhancers.push(devToolsExtension())
    }
}

const composedEnhancers = compose(applyMiddleware(...middleware), ...enhancers);
const protectedRoute = compose(Timers, RequireAuth);

const store = createStore(rootReducer, initialState, composedEnhancers);

ReactDOM.render(
    <Provider store={store}>
        <ConnectedRouter history={history}>
            <div>
                <Navbar />
                <App />
                <Switch>
                      // various routes go here...
                </Switch>
                {/*<Footer />*/}
            </div>
        </ConnectedRouter>
    </Provider>
    , document.querySelector('.container'));

全局 reducer 以及与触发错误的操作相关的 reducer 。

// ./react/reducers/index.js
import { combineReducers } from 'redux';
import { reducer as form } from 'redux-form';
import { routerReducer } from 'react-router-redux';
import documentReducer from './documents';

const rootReducer = combineReducers({
    form,
    router: routerReducer,
    documents: documentReducer,
});

export default rootReducer;

<小时/>

// ./react/reducers/documents.js
import {
    DOCUMENTS
} from '../actions/documents';

export default function(state = {}, action) {
    switch(action.type) {
        case DOCUMENTS:
            return { 
                ...state, 
                survey_id: action.payload.survey_id, 
            };
        default:
            return state;
    }

    return state;
}

最后，出现错误时调用的操作。 需要指出的一件重要事情:当 axios.post 不在 _.map 中时(实际上是任何类型的数组迭代)，不会发生错误。但是，这只发送一个文件，这不是我想要的行为。

// ./react/actions/documents.js
import _ from 'lodash';
import axios from 'axios';
import { push } from 'react-router-redux';
import { ROOT_URL } from '../../config/config.json';

// Establish the different types
export const DOCUMENTS = 'documents';

export function submitDocument(files) {
    const uploaders = _.map(files, f => {
        const formData = new FormData();

        formData.append('file', f);

        return axios.post(
            `${ROOT_URL}/api/documents/fileupload`,
            formData,
            { headers: 
                { 
                    'content-type': 'multipart/form-data',
                    'Authorization': 'JWT ' +  sessionStorage.getItem('token')
                }
            }            
        )

    });

    axios.
        all(uploaders)
        .then(response => {
            console.log('Success');
        })
        .catch(error => {
            console.log('Failed');
        })
}

调用该操作的容器可能也会有所帮助:

// ./react/containers/documents/submit_documents.js
import _ from 'lodash';
import React, { Component } from 'react';
import { connect } from 'react-redux';
import { submitDocument } from '../../actions/documents';
import Dropzone from 'react-dropzone';

class SubmitDocuments extends Component {

    constructor() {
        super();
        this.state = {
            filesToBeSent: [],
            filesPreview: [],
        }

        this.handleClick = this.handleClick.bind(this);
        this.handleSubmit = this.handleSubmit.bind(this);
        this.onDrop = this.onDrop.bind(this);
    }

    handleSubmit(event) {
        event.preventDefault();
        this.props.submitDocument(this.state.filesToBeSent);
    }

    onDrop(acceptedFiles) {
        var filesToBeSent = this.state.filesToBeSent;       
        _.map(acceptedFiles, f => {
            filesToBeSent.unshift(f);
        });

        filesToBeSent = _.uniqBy(filesToBeSent, 'name');

        var filesPreview = [];

        _.map(filesToBeSent, i => {
            filesPreview.unshift(
                <div key={i.name}>
                    <h5>{i.name} - {i.size} bytes</h5>
                </div>
            )            
        });

        this.setState({
            filesToBeSent,
            filesPreview
        });
    }

    render() {
        return (
            <form onSubmit={this.handleSubmit}>
                <div className='panel panel-default'>
                    <div className='panel-heading'>
                        <h4><strong>Submit Documents</strong></h4>
                    </div>

                    <div className='panel-body'>
                        <Dropzone className='dropzone' onDrop={this.onDrop}> 
                            <h3>Click to add files or drag files here to upload</h3>
                        </Dropzone>
                        {this.state.filesPreview}
                        <button type='submit' disabled={this.state.filesPreview.length < 1} className='btn btn-primary'>Submit</button>
                        <button type='button' className='btn btn-danger' onClick={this.handleClick}>Cancel</button>
                    </div>
                </div>
            </form>
        ); 
    }
}

function mapStateToProps(state) {
    return {
        survey_id: state.documents.survey_id
    }
}

export default connect(mapStateToProps, { submitDocument })(SubmitDocuments);

此外，由于错误中提到了 webpack，因此这是它的配置:

var path = require('path')
var webpack = require('webpack')
var BundleTracker = require('webpack-bundle-tracker')
var ExtractTextPlugin = require('extract-text-webpack-plugin')

module.exports = {
  context: __dirname,

  entry: [
    '../react/index'  
  ],

  output: {
      path: path.resolve('./src/assets/bundles/'),
      filename: './js/[name]-[hash].js'
  },

  plugins: [
    new BundleTracker({filename: './src/config/webpack-stats.json'}),
    new ExtractTextPlugin({filename: './css/[name].[hash].css', allChunks: true})
  ],

  module: {
    loaders: [
      // {test: /\.(jpe?g|png|gif|svg)$/i, loader: "url-loader?name=img/[name].[ext]"},
      { 
        test: /\.jsx?$/, 
        exclude: /node_modules/, 
        loader: 'babel-loader',
        query: {
          presets: ["react", "es2015", "stage-1"]
        }
      },
      {
        test: /\.json$/,
        loader: ['json-loader'] 
      },
      {
        test: /\.scss$/,
        loader: ['style-loader', 'css-loader', 'sass-loader'] 
      },
      {
        test: /\.scss$/,
        use: ExtractTextPlugin.extract({
          fallback: 'style-loader',
          use: 'css-loader'
        })      
      },   
    ],
  },

  resolve: {
    extensions: ['*', '.js', '.jsx', '.gif']
  }
}

无论如何，不​​确定是什么原因造成的，几天来一直在尝试解决它。一切正常，否则看起来不专业。

Answer 1

就我而言，LastPass 扩展程序导致了此错误，而不是我的代码 (onloadwff.js)。
通过删除扩展来修复它。

<小时/>

根据 lastpass-cli/issues/428#comment ，您可以通过将 LastPass 扩展设置更新为仅在单击时运行来避免这种情况。