Notify from inner flatMap - rxjs

Question

Here a quite complex sample:
Main:
this.runInstructionAndGetResult().subscribe({
next: val => console.log(`NEXT VALUE: ${val}`),
error: val => console.log(`ERROR VALUE: ${val}`),
complete: val => console.log(`COMPLETE`)
});
Observables:
public runInstructionAndGetResult(): Observable<string> {
return this.runAnInstruction()
.flatMap((data) => {
console.info("flatMap of runAnInstruction:", data);
return this.getInstructionExecutionStatusInPolling()
.filter(data => data != "Polling")
.take(1)
.flatMap((data) => {
console.info("flatMap of getInstructionExecutionStatusInPolling:", data);
return this.getInstructionResult();
}).map((data) => {
console.info("Map of getInstructionResult:", data);
return data;
});
});
}
public runAnInstruction(): Observable<string> {
return Observable.of("StartRun");
}
public getInstructionResult(): Observable<string> {
return Observable.of("FinalResult");
}
public getInstructionExecutionStatusInPolling(): Observable<string> {
return Observable.interval(1000)
.concatMap(data => {
return this.getInstructionExecutionStatus();
});
}
public getInstructionExecutionStatus(): Observable<string> {
return Observable.of("Polling", "Terminate");
}
Here plunk:
https://plnkr.co/edit/c1cahMtVARQnLgnHWlEe?p=preview
Main problem is that i just would like to be notify about "evolution" of inner stream outside.
Right now we have "next" event on main only when all inner flatMap are completed.
How to get notify? How can i emit explicit values to main stream for example during polling?
Thanks.

Answer 1

I found a solution to share.
Here plunker updated:
https://plnkr.co/edit/c1cahMtVARQnLgnHWlEe?p=preview
Basically i create a simple observable using : https://github.com/Reactive-Extensions/RxJS/blob/master/doc/api/core/operators/create.md
then i call programmatically next method and complete finally:
public runInstructionAndGetResult(): Observable<string> {
return Observable.create((ops)=> {
ops.next(1);
this.runAnInstruction()
.concatMap((data) => {
ops.next(2);
console.info("flatMap of runAnInstruction:", data);
return this.getInstructionExecutionStatusInPolling()
.filter(data => data != "Polling")
.take(1)
.concatMap((data) => {
ops.next(3);
console.info("flatMap of getInstructionExecutionStatusInPolling:", data);
return this.getInstructionResult();
}).map((data) => {
console.info("Map of getInstructionResult:", data);
ops.next(4);
ops.complete();
return data;
});
}).subscribe();
});
}