Angular + amazon-cognito-identity-js，为什么我收到错误 : global is not defined

Question

从命令行:

ng new sandbox
cd .\sandbox\
ng serve

打开http://localhost:4200/ 。它有效。

npm install --save amazon-cognito-identity-js

在 \src\app\sign-up\sign-up.component.ts 内添加以下代码行:

import * as AmazonCognitoIdentity from 'amazon-cognito-identity-js';

添加构造函数:

  constructor() {
    new AmazonCognitoIdentity.CognitoUserPool({});
  }

刷新http://localhost:4200/ .

页面为空白。控制台出现错误:

Uncaught ReferenceError: global is not defined
    at Object../node_modules/buffer/index.js (index.js:43)
    at __webpack_require__ (bootstrap:76)
    at Object../node_modules/amazon-cognito-identity-js/es/AuthenticationHelper.js (AuthenticationHelper.js:1)
    at __webpack_require__ (bootstrap:76)
    at Object../node_modules/amazon-cognito-identity-js/es/index.js (index.js:1)
    at __webpack_require__ (bootstrap:76)
    at Object../src/app/app.component.ts (main.js:94)
    at __webpack_require__ (bootstrap:76)
    at Object../src/app/app.module.ts (app.component.ts:9)
    at __webpack_require__ (bootstrap:76)

解决此错误的最佳方法是什么？

Answer 1

将其作为 /src/polyfills.ts 中的最后一行

(window as any).global = window