问题

创建新的Angular Universal应用程序时，会生成一个server.ts文件，用于处理服务器端渲染（SSR）过程。如果您需要发出服务器请求来执行后端功能，似乎必须使用采用的服务器框架Express.js构建一个RESTful API，正如这两个示例这里和这里所描述的那样。但是，这两个示例都已经超过四年了。

要执行后端功能，我是否需要扩展生成的server.ts文件，如上述链接中所描述的？或者，Angular Universal是否提供了不同的方法或模式？与Angular组件或服务相比，我是否可以在此服务中运行后端功能？

我理解需要一个HTTP请求的实现，其中Express服务器会监听它。然而，我期望Angular Universal提供了一个额外的层次来简化这个过程。

由Angular Universal生成的server.ts文件：

import 'zone.js/node';

import { APP_BASE_HREF } from '@angular/common';
import { ngExpressEngine } from '@nguniversal/express-engine';
import * as express from 'express';
import { existsSync } from 'node:fs';
import { join } from 'node:path';
import { AppServerModule } from './src/main.server';

// 导出Express应用程序，以便它可以被无服务器函数使用。
export function app(): express.Express {
  const server = express();
  const distFolder = join(process.cwd(), 'dist/antiquetrade-ssr/browser');
  const indexHtml = existsSync(join(distFolder, 'index.original.html')) ? 'index.original.html' : 'index';

  // 我们的Universal express-engine（在https://github.com/angular/universal/tree/main/modules/express-engine找到）
  server.engine('html', ngExpressEngine({
    bootstrap: AppServerModule
  }));

  server.set('view engine', 'html');
  server.set('views', distFolder);

  // 示例Express Rest API端点
  // server.get('/api/**', (req, res) => { });
  // 从/browser目录下提供静态文件
  server.get('*.*', express.static(distFolder, {
    maxAge: '1y'
  }));

  // 所有常规路由使用Universal引擎
  server.get('*', (req, res) => {
    res.render(indexHtml, { req, providers: [{ provide: APP_BASE_HREF, useValue: req.baseUrl }] });
  });

  return server;
}

function run(): void {
  const port = process.env['PORT'] || 4000;

  // 启动Node服务器
  const server = app();
  server.listen(port, () => {
    console.log(`Node Express服务器正在监听http://localhost:${port}`);
  });
}

// Webpack将使用'__webpack_require__'替换'require'
// '__non_webpack_require__'是Node 'require'的代理
// 以下代码是为了确保仅在不需要捆绑时运行服务器。
declare const __non_webpack_require__: NodeRequire;
const mainModule = __non_webpack_require__.main;
const moduleFilename = mainModule && mainModule.filename || '';
if (moduleFilename === __filename || moduleFilename.includes('iisnode')) {
  run();
}

export * from './src/main.server';

<details>
<summary>英文:</summary>
When creating a new Angular Universal app, a server.ts file is generated to handle the server-side rendering (SSR) process. If you need to make a server request to execute a backend function, it seems that you have to build a RESTful API using the adopted server framework Express.js as those two examples [here][1] and [here][2] describe. However, both examples are older than four years. 
To execute backend functions, do I need to extend the generated server.ts file as described in the aforementioned links? Alternatively, does Angular Universal offer a different approach or pattern? Something compare to angular component or service, where I can also run the backend function within this service.
I understand that there needs to be an implementation of an http request, where the Express server listens for it. However, I expected that Angular Universal provides an additional layer to simplify this process. 
server.ts file generated by angular universal:
import &#39;zone.js/node&#39;;
import { APP_BASE_HREF } from &#39;@angular/common&#39;;
import { ngExpressEngine } from &#39;@nguniversal/express-engine&#39;;
import * as express from &#39;express&#39;;
import { existsSync } from &#39;node:fs&#39;;
import { join } from &#39;node:path&#39;;
import { AppServerModule } from &#39;./src/main.server&#39;;
// The Express app is exported so that it can be used by serverless Functions.
export function app(): express.Express {
const server = express();
const distFolder = join(process.cwd(), &#39;dist/antiquetrade-ssr/browser&#39;);
const indexHtml = existsSync(join(distFolder, &#39;index.original.html&#39;)) ? &#39;index.original.html&#39; : &#39;index&#39;;
// Our Universal express-engine (found @ https://github.com/angular/universal/tree/main/modules/express-engine)
server.engine(&#39;html&#39;, ngExpressEngine({
bootstrap: AppServerModule
}));
server.set(&#39;view engine&#39;, &#39;html&#39;);
server.set(&#39;views&#39;, distFolder);
// Example Express Rest API endpoints
// server.get(&#39;/api/**&#39;, (req, res) =&gt; { });
// Serve static files from /browser
server.get(&#39;*.*&#39;, express.static(distFolder, {
maxAge: &#39;1y&#39;
}));
// All regular routes use the Universal engine
server.get(&#39;*&#39;, (req, res) =&gt; {
res.render(indexHtml, { req, providers: [{ provide: APP_BASE_HREF, useValue: req.baseUrl }] });
});
return server;
}
function run(): void {
const port = process.env[&#39;PORT&#39;] || 4000;
// Start up the Node server
const server = app();
server.listen(port, () =&gt; {
console.log(`Node Express server listening on http://localhost:${port}`);
});
}
// Webpack will replace &#39;require&#39; with &#39;__webpack_require__&#39;
// &#39;__non_webpack_require__&#39; is a proxy to Node &#39;require&#39;
// The below code is to ensure that the server is run only when not requiring the bundle.
declare const __non_webpack_require__: NodeRequire;
const mainModule = __non_webpack_require__.main;
const moduleFilename = mainModule &amp;&amp; mainModule.filename || &#39;&#39;;
if (moduleFilename === __filename || moduleFilename.includes(&#39;iisnode&#39;)) {
run();
}
export * from &#39;./src/main.server&#39;;
[1]: https://stackoverflow.com/questions/44734307/how-to-make-http-post-request-in-angular-4-universal
[2]: https://github.com/SinghDigamber/angular-universal-crud
</details>
# 答案1
**得分**: 2
Angular不是一个可以运行任何后台服务的框架。Angular Universal 主要负责在服务器上渲染应用程序。在你的 server.ts 文件中，你可以看到以下代码：
```typescript
// 示例 Express Rest API 端点
// server.get('/api/**', (req, res) => { });

在这里，你可以按照常规的 Express 框架模式来运行服务器上的任务（如果需要）。总体而言，Angular Universal 不像其他 SSR 框架，比如 Laravel。它只是将 Angular 绑定到 Express 服务器，以便在服务器上渲染 Angular 应用程序。

// Example Express Rest API endpoints
// server.get('/api/**', (req, res) => { });