How to get full base URL (including server, port and protocol) in Angular Universal?

Question

I need to get the full base URL (e.g. http://localhost:5000 or https://productionserver.com) of my Angular 2 app so that I can pass it along to a 3rd party service in the co

Answer 1

You’ll find that all content coming from Http requests won’t be pre-rendered: it’s because Universal needs absolute URLs.

As your development and production server won’t have the same URL, it’s quite painful to manage it on your own.

My solution to automate this : using the new HttpClient interceptor feature of Angular 4.3, combined with the Express engine.

The interceptor catches all requests when in server context to prepend the full URL.

import { Injectable, Inject, Optional } from '@angular/core';
 import { HttpInterceptor, HttpHandler, HttpRequest } from'@angular/common/http';
 @Injectable()
 export class UniversalInterceptor implements HttpInterceptor {
  constructor(@Optional() @Inject('serverUrl') protected serverUrl: string) {}
  intercept(req: HttpRequest, next: HttpHandler) {
    const serverReq = !this.serverUrl ? req : req.clone({
      url: ``${this.serverUrl}${req.url}``
    });
    return next.handle(serverReq);
  }
}

Then provide it in your AppServerModule :

import { NgModule } from '@angular/core';
import { ServerModule } from '@angular/platform-server';
import { HTTP_INTERCEPTORS } from '@angular/common/http';
import { AppModule } from './app.module';
import { AppComponent } from './app.component';
import { UniversalInterceptor } from './universal.interceptor';
@NgModule({
  imports: [
    AppModule,
    ServerModule
  ],
  providers: [{
    provide: HTTP_INTERCEPTORS,
    useClass: UniversalInterceptor,
    /* Multi is important or you will delete all the other interceptors */
    multi: true
  }],
  bootstrap: [AppComponent]
})
export class AppServerModule {}

Now you can use Express engine to pass the full URL to Angular, just update your server.js :

 function angularRouter(req, res) { 
  res.render('index', {
    req,
    res,
    providers: [{
      provide: 'serverUrl',
      useValue: `${req.protocol}://${req.get('host')}`
    }]
  });
}