D-Net

import { Injectable, OnInit, PLATFORM_ID, Inject } from '@angular/core';

import { isPlatformBrowser} from '@angular/common';

import { Http, Response, Headers, RequestOptions } from '@angular/http';

import { Observable, Subscription, BehaviorSubject } from 'rxjs/Rx';

import 'rxjs/add/operator/map';

import 'rxjs/add/operator/catch';

import 'rxjs/add/operator/toPromise';

import { EnvProperties } from './env-properties';

@Injectable()

export class EnvironmentSpecificService {

  public envSpecific: EnvProperties;

  public envSpecificNull: EnvProperties = null;

  testBrowser: boolean;

  private envSpecificSubject: BehaviorSubject<EnvProperties> = new BehaviorSubject<EnvProperties>(null);

  private propertiesUrl = (process.env.PROP_URL)?process.env.PROP_URL:"./assets/env-properties.json";

  constructor(private http: Http,@Inject(PLATFORM_ID) platformId: string) {

      this.testBrowser = isPlatformBrowser(platformId);

      if (this.testBrowser) {

          //this is only executed on the browser

      }

    console.log('EnvironmentSpecificService created ' +this.testBrowser);

/*

down vote

import { PLATFORM_ID, Inject } from '@angular/core';

import { isPlatformBrowser} from '@angular/common';

...

export class MyComponent {

...

    testBrowser: boolean;

    constructor(

        @Inject(PLATFORM_ID) platformId: string) {

            this.testBrowser = isPlatformBrowser(platformId);

            if (this.testBrowser) {

                //this is only executed on the browser

            }

    }

*/

  }

  public loadEnvironment() {

      // Only want to do this once - if root page is revisited, it calls this again.

      if (this.envSpecific === null || this.envSpecific === undefined) {

        console.log('Loading env-properties.json');

        return this.http.get(this.propertiesUrl)

            .map((data) => data.json())

            .toPromise<EnvProperties>();

      }

      return Promise.resolve(this.envSpecificNull);

  }

  public setEnvProperties(es: EnvProperties) {

    // This has already been set so bail out.

    if (es === null || es === undefined) {

        return;

    }

    this.envSpecific = es;

    console.log(this.envSpecific);

    if (this.envSpecificSubject) {

        this.envSpecificSubject.next(this.envSpecific);

    }

  }

  /*

    Call this if you want to know when EnvProperties is set.

  */

  public subscribe(caller: any, callback: (caller: any, es: EnvProperties) => void) {

      this.envSpecificSubject

          .subscribe((es) => {

              if (es === null) {

                  return;

              }

              callback(caller, es);

          });

  }

}