Best way to get a value from service file to app.module

Question

I wish to import a value returned from a service file let's say for example the service file is:

http.service.ts

selectedEnvironment() {
  return "abc";
}

But how can I get this value into my app.module file. Is there a preferred way?

I tried:

app.module

import { HttpService } from "./http.service";

export function HttpLoaderFactory(httpClient: HttpClient) {
  return new TranslateHttpLoader(httpClient, "./assets/" + HttpService.selectedEnvironment()+"/i18n/", ".json");
}

But it says "Property selectedEnvironment does not exist on type typeof HttpService ".

Answer 1

If it's an Angular Service

import { Injectable } from "@angular/core";

@Injectable()
export class YourHttpService {
  constructor() {}

  getEnvironment() {
    return "XYZ";
  }
}

You can specify the service as a parameter in HttpLoaderFactory . Please make sure that service name is specified in deps: [HttpClient,YourHttpService ] as well as in providers providers: [YourHttpService], of your app module

export function HttpLoaderFactory(httpClient: HttpClient,httpService:YourHttpService) {
    console.log(httpService.getEnvironment());
  return new TranslateHttpLoader(httpClient);
}

@NgModule({
  declarations: [
    AppComponent
  ],
  imports: [
    BrowserModule,
    HttpClientModule,
    TranslateModule.forRoot({
      loader: {
        provide: TranslateLoader,
        useFactory: HttpLoaderFactory,
        deps: [HttpClient,YourHttpService]
      }
    })
  ],
  providers: [YourHttpService],
  bootstrap: [AppComponent]
})
export class AppModule { }

Sample Code https://stackblitz.com/edit/transalate-vvmckq?file=src/app/app.module.ts

Answer 2

在app.module.ts中添加此

 providers: [HttpService]