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

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<string> {  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());  }}

As of July 2018 and the release of RxJS 6, the new way to get an Observable from a value is to import the of operator like so:

import { of } from 'rxjs';

and then create the observable from the value, like so:

of(someValue);

Note, that you used to have to do Observable.of(someValue) like in the currently accepted answer. There is a good article on the other RxJS 6 changes here.

Things seem to have changed since Angular 2.0.0

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

The .next() function will be called on your subscriber.