@nguniversal/express-engine

Express Engine for running Server Angular Apps

Usage no npm install needed!

<script type="module">
  import nguniversalExpressEngine from 'https://cdn.skypack.dev/@nguniversal/express-engine';
</script>

README

Angular Express Engine

This is an Express Engine for running Angular Apps on the server for server side rendering.

Usage

npm install @nguniversal/express-engine --save

To use it, set the engine and then route requests to it

import express from 'express';
import { ngExpressEngine } from '@nguniversal/express-engine';

const app = express();

// Set the engine
app.engine(
  'html',
  ngExpressEngine({
    bootstrap: ServerAppModule, // Give it a module to bootstrap
  }),
);

app.set('view engine', 'html');

app.get('/**/*', (req: Request, res: Response) => {
  res.render('../dist/index', {
    req,
    res,
  });
});

Configuring the URL and Document

It is possible to override the default URL and document fetched when the rendering engine is called. To do so, simply pass in a url and/or document string to the renderer as follows:

app.get('/**/*', (req: Request, res: Response) => {
  let url = 'http://someurl.com';
  let doc = '<html><head><title>New doc</title></head></html>';
  res.render('../dist/index', {
    req,
    res,
    url,
    document: doc,
  });
});

Extra Providers

Extra Providers can be provided either on engine setup

app.engine(
  'html',
  ngExpressEngine({
    bootstrap: ServerAppModule,
    providers: [ServerService],
  }),
);

Advanced Usage

Request based Bootstrap

The Bootstrap module as well as more providers can be passed on request

app.get('/**/*', (req: Request, res: Response) => {
  res.render('../dist/index', {
    req,
    res,
    bootstrap: OtherServerAppModule,
    providers: [OtherServerService],
  });
});

Using the Request and Response

The Request and Response objects are injected into the app via injection tokens. You can access them by @Inject

import { Request } from 'express';
import { REQUEST } from '@nguniversal/express-engine/tokens';

@Injectable()
export class RequestService {
  constructor(@Inject(REQUEST) private request: Request) {}
}

If your app runs on the client side too, you will have to provide your own versions of these in the client app.

Using a Custom Callback

You can also use a custom callback to better handle your errors

app.get('/**/*', (req: Request, res: Response) => {
  res.render(
    '../dist/index',
    {
      req,
      res,
    },
    (err: Error, html: string) => {
      res.status(html ? 200 : 500).send(html || err.message);
    },
  );
});