Импорт mongodb в js-файл переднего плана с веб-пакетом вызывает ошибку - PullRequest
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Импорт mongodb в js-файл переднего плана с веб-пакетом вызывает ошибку

0 голосов
/ 27 августа 2018

Я использую трюфельный пакет для создания Dapp, теперь я хочу использовать mongoDB для хранения и извлечения информации.При импорте модуля MongoDB webpack sever выдает ошибку, без бита import from 'mongodb' все работает нормально.Из того, что я могу понять, так как мой app.js файл находится на стороне клиента, я не могу просто импортировать его, но это то, для чего предназначен Webpack, плюс я дополнительно установил mongodb модуль локально, например: npm install mongodb --save и npm install mongodb --save-dev

Это ошибка: 

ERROR in ./~/mongodb/lib/url_parser.js
Module not found: Error: Can't resolve 'dns' in '/home/nik/ethereumStockExchange/node_modules/mongodb/lib'
 @ ./~/mongodb/lib/url_parser.js 7:8-22
 @ ./~/mongodb/lib/operations/mongo_client_ops.js
 @ ./~/mongodb/lib/mongo_client.js
 @ ./~/mongodb/index.js
 @ ./app/javascripts/app.js
 @ multi (webpack)-dev-server/client?http://localhost:8080 ./app/javascripts/app.js

ERROR in ./~/mongodb-core/lib/uri_parser.js
Module not found: Error: Can't resolve 'dns' in '/home/nik/ethereumStockExchange/node_modules/mongodb-core/lib'
 @ ./~/mongodb-core/lib/uri_parser.js 4:12-26
 @ ./~/mongodb-core/index.js
 @ ./~/mongodb/index.js
 @ ./app/javascripts/app.js
 @ multi (webpack)-dev-server/client?http://localhost:8080 ./app/javascripts/app.js

ERROR in ./~/mongodb-core/lib/connection/connection.js
Module not found: Error: Can't resolve 'net' in '/home/nik/ethereumStockExchange/node_modules/mongodb-core/lib/connection'
 @ ./~/mongodb-core/lib/connection/connection.js 5:8-22
 @ ./~/mongodb-core/index.js
 @ ./~/mongodb/index.js
 @ ./app/javascripts/app.js
 @ multi (webpack)-dev-server/client?http://localhost:8080 ./app/javascripts/app.js

ERROR in ./~/mongodb-core/lib/connection/connection.js
Module not found: Error: Can't resolve 'tls' in '/home/nik/ethereumStockExchange/node_modules/mongodb-core/lib/connection'
 @ ./~/mongodb-core/lib/connection/connection.js 6:8-22
 @ ./~/mongodb-core/index.js
 @ ./~/mongodb/index.js
 @ ./app/javascripts/app.js
 @ multi (webpack)-dev-server/client?http://localhost:8080 ./app/javascripts/app.js

ERROR in ./~/require_optional/~/resolve-from/index.js
Module not found: Error: Can't resolve 'module' in '/home/nik/ethereumStockExchange/node_modules/require_optional/node_modules/resolve-    from'
 @ ./~/require_optional/~/resolve-from/index.js 3:13-30
 @ ./~/require_optional/index.js
 @ ./~/mongodb-core/index.js
 @ ./~/mongodb/index.js
 @ ./app/javascripts/app.js
 @ multi (webpack)-dev-server/client?http://localhost:8080 ./app/javascripts/app.js

ERROR in ./~/require_optional/index.js
Module not found: Error: Can't resolve 'fs' in '/home/nik/ethereumStockExchange/node_modules/require_optional'
 @ ./~/require_optional/index.js 2:7-20
 @ ./~/mongodb-core/index.js
 @ ./~/mongodb/index.js
 @ ./app/javascripts/app.js
 @ multi (webpack)-dev-server/client?http://localhost:8080 ./app/javascripts/app.js

ERROR in ./~/mongodb/lib/gridfs/grid_store.js
Module not found: Error: Can't resolve 'fs' in '/home/nik/ethereumStockExchange/node_modules/mongodb/lib/gridfs'
 @ ./~/mongodb/lib/gridfs/grid_store.js 42:11-24
 @ ./~/mongodb/index.js
 @ ./app/javascripts/app.js
 @ multi (webpack)-dev-server/client?http://localhost:8080 ./app/javascripts/app.js

webpack: Failed to compile.

Это мой app.js файл, который упоминается как скрипт в моем index.html

// Import libraries we need.
import { default as Web3} from 'web3';
import { default as contract } from 'truffle-contract';
import listing_artifacts from '../../build/contracts/Listing.json';

import Mongo from 'mongodb';

// Updates the address and balance
window.updateBalance = function() {
  console.log("Updating balance\nDefault account:  " + web3.eth.defaultAccount + "\nCurrent balance:  " + web3.eth.getBalance(web3.eth.defaultAccount));
  $("#addressAndBalance").html("ADDRESS:&nbsp&nbsp&nbsp" + web3.eth.defaultAccount + "&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp BALANCE:&nbsp&nbsp&nbsp" + web3.eth.getBalance(web3.eth.defaultAccount).toString());
}

$(document).ready(function() {
  // This is used on startup in order to set up
  // the connection the Ethereum node
  if (typeof web3 !== 'undefined') {
    console.warn("Using web3 detected from external source like Metamask")
    // Use Mist/MetaMask's provider
    window.web3 = new Web3(web3.currentProvider);
  } else {
    console.warn("No web3 detected. Falling back to http://localhost:8545.");
    // fallback - use your fallback strategy (local node / hosted node + in-dapp id mgmt / fail)
    window.web3 = new Web3(new    Web3.providers.HttpProvider("http://localhost:8545"));
 }

  console.log("Accounts:  " + web3.eth.accounts);
   web3.eth.defaultAccount = web3.eth.accounts[0];
  updateBalance();
});

Этомой webpack.config.js

const path = require('path');
const CopyWebpackPlugin = require('copy-webpack-plugin');
//const mongo = require('mongodb');

module.exports = {
  entry: './app/javascripts/app.js',
  output: {
    path: path.resolve(__dirname, 'build'),
    filename: 'app.js'
  },
  plugins: [
    // Copy our app's index.html to the build folder.
    new CopyWebpackPlugin([
      { from: './app/index.html', to: "index.html" }
    ])
  ],
  module: {
    rules: [
      {
       test: /\.css$/,
       use: [ 'style-loader', 'css-loader' ]
      }
    ],
    loaders: [
      { test: /\.json$/, use: 'json-loader' },
      {
        test: /\.js$/,
        exclude: /(node_modules|bower_components)/,
        loader: 'babel-loader',
        query: {
          presets: ['es2015'],
          plugins: ['transform-runtime']
         }
      }
     ]
  }
}

Это мой package.json файл: 

{
  "name": "truffle-init-webpack",
  "version": "0.0.2",
  "description": "Frontend example using truffle v3",
  "scripts": {
    "lint": "eslint ./",
    "build": "webpack",
    "dev": "webpack-dev-server"
  },
  "author": "Douglas von Kohorn",
  "license": "MIT",
  "devDependencies": {
    "babel-cli": "^6.22.2",
    "babel-core": "^6.22.1",
    "babel-eslint": "^6.1.2",
    "babel-loader": "^6.2.10",
    "babel-plugin-transform-runtime": "^6.22.0",
    "babel-preset-env": "^1.1.8",
    "babel-preset-es2015": "^6.22.0",
    "babel-register": "^6.22.0",
    "copy-webpack-plugin": "^4.0.1",
    "css-loader": "^0.26.1",
    "eslint": "^3.14.0",
    "eslint-config-standard": "^6.0.0",
    "eslint-plugin-babel": "^4.0.0",
    "eslint-plugin-mocha": "^4.8.0",
    "eslint-plugin-promise": "^3.0.0",
    "eslint-plugin-standard": "^2.0.0",
    "fs": "0.0.1-security",
    "html-webpack-plugin": "^2.28.0",
    "json-loader": "^0.5.4",
    "mongodb": "^3.1.4",
    "style-loader": "^0.13.1",
    "truffle-contract": "^1.1.11",
    "webpack": "^2.2.1",
    "webpack-dev-server": "^2.3.0"
  },
  "dependencies": {
    "web3": "^0.20.2"
  }
}

Ответы [ 2 ]

0 голосов
/ 28 августа 2018

Вместо использования mongoDB на стороне клиента (что может быть возможно при использовании http rest api), я использовал indexedDB, встроенный в браузер.

0 голосов
/ 27 августа 2018

Вы не можете импортировать модуль mongodb в свой код на стороне клиента.Да, конечно!Вы можете импортировать модули узлов с помощью веб-пакета, но поскольку mongodb является библиотекой nodejs, здесь это невозможно.Но любая библиотека на стороне клиента в node_modules в порядке.

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