Convert Angular 4 web app to Angular Universal app

Question

I have a requirement to convert Angular 4 web app to Angular Universal.The reason for that is currently, the web app is not able to be properly indexed by Google (and Facebook social previews thumbnails) because it's a single page app and rendered on the client side.So now I need to implement Angular Universal, server-side rendering.

I got the knowledge of how to create a new Angular Universal app using this great video series.

Question: Can you please tell me the direction which I have to follow the convert existing app as an Angular Universal one.Maybe a nice URL or steps or whatever the direction will be highly appreciated.

Note: Here angular version is not a problem.Either 2 or 4.

Answer 1

From this blog (web archive backup)

First npm install --save @angular/platform-server @angular/animations

Edit /src/app/app.module.ts and change the BrowserModule import to BrowserModule.withServerTransition({appId: 'your-app-name'}),

Create a file /src/app/app.server.module.ts

import { NgModule } from '@angular/core';
import { ServerModule } from '@angular/platform-server';
import { AppModule } from './app.module';
import { AppComponent } from './app.component';

@NgModule({
imports: [
    ServerModule,
    AppModule
],
bootstrap: [AppComponent]
})
export class AppServerModule { }

Create a file /src/server.ts

import 'reflect-metadata';
import 'zone.js/dist/zone-node';
import { platformServer, renderModuleFactory } from '@angular/platform-server'
import { enableProdMode } from '@angular/core'
import { AppServerModuleNgFactory } from '../dist/ngfactory/src/app/app.server.module.ngfactory'
import * as express from 'express';
import { readFileSync } from 'fs';
import { join } from 'path';

const PORT = 4000;

enableProdMode();

const app = express();

let template = readFileSync(join(__dirname, '..', 'dist', 'index.html')).toString();

app.engine('html', (_, options, callback) => {
  const opts = { document: template, url: options.req.url };

  renderModuleFactory(AppServerModuleNgFactory, opts)
    .then(html => callback(null, html));
});

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

app.get('*.*', express.static(join(__dirname, '..', 'dist')));

app.get('*', (req, res) => {
  res.render('index', { req });
});

app.listen(PORT, () => {
  console.log(`listening on http://localhost:${PORT}!`);
});

Edit /src/tsconfig.app.json and add server.ts to the exclude array

Edit /tsconfig.json and after the "compilerOptions" node add the following

"angularCompilerOptions": {
    "genDir": "./dist/ngfactory",
    "entryModule": "./src/app/app.module#AppModule"
} 

Edit package.json and change the "scripts" section by adding "prestart" and altering "start"

"prestart": "ng build --prod && ngc",
"start": "ts-node src/server.ts"

You can now type npm run start in your console/terminal window and it will build everything and start serving on port 4000.

It doesn't watch the source or do hot-module-replacing etc, but once the server is running you can also type ng serve (assuming you are using the @angular/cli npm package) in another window and edit your single-page-app as you normally would and use npm run start only when rebuilding or changing server code.

Answer 2

Angular Universal is a better choice with regards to better SEO indexing. You have raised very nice concern about the migration of current Angular 4 project to Universal. However, with ANgular 4 release they have packaged universal with it. I will write a tutorial regarding it and share it with you soon.

However, you can try ng-universal-cli? https://www.npmjs.com/package/ng-universal-cli

With this, you can setup your new Angular 4 Univeral project with one command ngu new <project-name>

You can then move your existing project files to this newly created project.