Angular4 + Universal + ng-bootstrap出现“意外的令牌导入”错误

Question

所以我升级到了角度4+，这样我就可以利用通用包进行服务器端渲染以实现搜索引擎优化目的。 我在现有的angular 2+项目中实现了这一点，将其升级为angular 4+并从https://github.com/evertonrobertoauler/cli-universal-demo/commit/a2610286bd3db5d4f4cce4318d7c220c11963eb6完成了所有必要的配置。

我使用ng-bootstrap https://ng-bootstrap.github.io/#/home(v1.0.0- alpha.22）只有一个区别。 但是当我使用npm run start-u-dev运行节点服务器时，我在ng-bootstrap中的import关键字出现了这个错误。

---

app-ui@0.0.0 start-u-dev /Users/giric/Projects/apnaDoctor/webapp/appUI  
ts-node src/server.ts  

/appUI/node_modules/@ng-bootstrap/ng-bootstrap/accordion/accordion.module.js:1
(function (exports, require, module, __filename, __dirname) { import { NgModule } from '@angular/core';  
                                                              ^^^^^^  
SyntaxError: Unexpected token import  
    at createScript (vm.js:53:10)  
    at Object.runInThisContext (vm.js:95:10)  
    at Module._compile (module.js:543:28)  
    at Object.Module._extensions..js (module.js:580:10)  
    at Module.load (module.js:488:32)  
    at tryModuleLoad (module.js:447:12)  
    at Function.Module._load (module.js:439:3)  
    at Module.require (module.js:498:17)  
    at require (internal/module.js:20:19)  
    at Object.<anonymous> (/appUI/dist/ngfactory/src/app/app.server.module.ngfa
ctory.ts:18:1)  
    at Module._compile (module.js:571:32)  
    at Module.m._compile (/appUI/node_modules/ts-node/src/index.ts:406:23)  
    at Module._extensions..js (module.js:580:10)  
    at Object.require.extensions.(anonymous function) [as .ts]
(/webapp/appUI/node_mod
ules/ts-node/src/index.ts:409:12)  
    at Module.load (module.js:488:32)  

pm ERR! Darwin 16.6.0  
npm ERR! argv "/usr/local/bin/node" "/usr/local/bin/npm" "run" "start-u-dev"  
npm ERR! node v7.7.4  
npm ERR! npm  v4.1.2  
npm ERR! code ELIFECYCLE  
npm ERR! app-ui@0.0.0 start-u-dev: `ts-node src/server.ts`  
npm ERR! Exit status 1  
npm ERR!  
npm ERR! Failed at the app-ui@0.0.0 start-u-dev script 'ts-node src/server.ts'.  
npm ERR! Make sure you have the latest version of node.js and npm installed.  
npm ERR! If you do, this is most likely a problem with the app-ui package,  
npm ERR! not with npm itself.  
npm ERR! Tell the author that this fails on your system:  
npm ERR!     ts-node src/server.ts  
npm ERR! You can get information on how to open an issue for this project with:  
npm ERR!     npm bugs app-ui  
npm ERR! Or if that isn't available, you can get their info via:  
npm ERR!     npm owner ls app-ui  
npm ERR! There is likely additional logging output above.  

npm ERR! Please include the following file with any support request:  

---

这就是我的package.json的样子

{  
  "name": "app-ui",  
  "version": "0.0.0",  
  "license": "MIT",  
  "scripts": {  
    "ng": "ng",  
    "start": "ng serve",  
    "build": "ng build",  
    "test": "ng test",
    "lint": "ng lint",
    "e2e": "ng e2e",
    "prestart": "npm install",
    "postinstall": "bower install",
    "prestart-u-dev": "npm install && ng build && ngc",
    "start-u-dev": "ts-node src/server.ts",
    "prestart-u-prod": "npm install && ng build --prod && ngc",
    "start-u-prod": "ts-node src/server.ts"
  },
  "private": true,
  "dependencies": {
    "@angular/animations": "^4.0.1",
    "@angular/cli": "^1.0.0-rc.1",
    "@angular/common": "^4.0.1",
    "@angular/compiler": "^4.0.1",
    "@angular/compiler-cli": "^4.0.1",
    "@angular/core": "^4.0.1",
    "@angular/forms": "^4.0.1",
    "@angular/http": "^4.0.1",
    "@angular/platform-browser": "^4.0.1",
    "@angular/platform-browser-dynamic": "^4.0.1",
    "@angular/platform-server": "^4.0.1",
    "@angular/router": "^4.0.1",
    "@ng-bootstrap/ng-bootstrap": "^1.0.0-alpha.22",
    "angular2-toaster": "^3.0.1",
    "core-js": "^2.4.1",
    "ng2-webstorage": "^1.5.1",
    "rxjs": "^5.1.0",
    "rxjs-es": "^5.0.0-beta.12",
    "typescript": "^2.2.2",
    "ui-router-ng2": "^1.0.0-beta.4",
    "zone.js": "^0.7.6"
  },
  "devDependencies": {
    "@types/jasmine": "2.5.38",
    "@types/node": "~6.0.60",
    "codelyzer": "~2.0.0",
    "jasmine-core": "~2.5.2",
    "jasmine-spec-reporter": "~3.2.0",
    "karma": "~1.4.1",
    "karma-chrome-launcher": "~2.0.0",
    "karma-cli": "~1.0.1",
    "karma-coverage-istanbul-reporter": "^0.2.0",
    "karma-jasmine": "~1.1.0",
    "karma-jasmine-html-reporter": "^0.2.2",
    "node-sass": "^4.5.0",
    "protractor": "~5.1.0",
    "raw-loader": "^0.5.1",
    "sass-loader": "^6.0.3",
    "ts-node": "~2.0.0",
    "tslint": "~4.4.2"
  }
}

更新：早些时候我删除了angular2-toaster，但后来又添加了它，以确保它不仅仅是烤箱模块抛出相同的错误。 事实证明，angular2-toaster和ng-bootstrap都犯了同样的错误。

更新2：当我使用ng服务器运行服务器时 ，它运行正常，使用ng-bootstrap和angular2-toaster与angular 4+没有任何问题

有什么建议？ 提前致谢。

Answer 1

对于那些试图了解解决方案的人来说，你基本上想要使用angular2-toaster和白名单angular2-toaster这个问题。

1. 如果使用angular-cli，请使用ng eject创建webpack.config.js

2. 通过npm install安装webpack-node-externals依赖项，并在webpack.config.js文件中添加以下行

    const nodeExternals = require('webpack-node-externals'); module.exports = { ... target: 'node', externals: [nodeExternals({ whitelist: [ /^@ng-bootstrap\\/ng-bootstrap/, /^angular2\\-toaster/, ] })], ... } 

Answer 2

这显然是一个构建问题 - 您似乎没有适当的服务器端代码的转换设置。 请注意， ng-bootstrap （与任何其他Angular 2.x +库！一样）以下列方式发送代码：

• 非捆绑式ES2015代码（带进口）
• UMD捆绑的ES5代码（不含导入）

如果你想在服务器上运行ng-bootstrap，你有两个选择：设置正确的转换管道和使用非捆绑代码或从bundle（位于bundles文件夹中）导入。

如果您决定采用ES5捆绑方法，则应该从@ng-bootstrap/ng-bootstrap/dist/ng-bootstrap而不仅仅是@ng-bootstrap/ng-bootstrap导入。 但要明确我不推荐它，因为你必须在服务器端和客户端代码中有不同的导入。

Answer 3

我想你可以创建两个模块。 一个是针对浏览器导入的ng-bootstrap，一个是针对服务器导入的ng-bootstrap。 我认为你必须创建一个共同的模块来共享组件，为浏览器模块和服务器模块提供服务。 Modal不会由服务器呈现给SEO。