How to create an Observable from static data similar to http one in Angular?

I am having a service that has this method:

export class TestModelService {

    public testModel: TestModel;

    constructor( @Inject(Http) public http: Http) {
    }

    public fetchModel(uuid: string = undefined): Observable {
        if(!uuid) {
            //return Observable of JSON.stringify(new TestModel());
        }
        else {
            return this.http.get("http://localhost:8080/myapp/api/model/" + uuid)
                .map(res => res.text());
        }
    }
}

in the component's constructor I am subscribing like this:

export class MyComponent {
   testModel: TestModel;
   testModelService: TestModelService;

   constructor(@Inject(TestModelService) testModelService) {
      this.testModelService = testModelService;

      testService.fetchModel("29f4fddc-155a-4f26-9db6-5a431ecd5d44").subscribe(
          data => { this.testModel = FactModel.fromJson(JSON.parse(data)); },
          err => console.log(err)
      );
   }
}

This works if an object comes from the server but I am trying to create an observable that will work with the given subscribe() call for a static string (this happens when testModelService.fetchModel() does not receive an uuid) so there is seamless handling in both cases.

Perhaps you could try to use the of method of the Observable class:

import { Observable } from 'rxjs/Observable';
import 'rxjs/add/observable/of';

public fetchModel(uuid: string = undefined): Observable {
  if(!uuid) {
    return Observable.of(new TestModel()).map(o => JSON.stringify(o));
  }
  else {
    return this.http.get("http://localhost:8080/myapp/api/model/" + uuid)
            .map(res => res.text());
  }
}

Stack Overflow Q#35219713, score: 189