Problem with Observable's expand function

Hi guys, i tried to use the expand() function on Observable object, but it returned always an empty Observable.

This is my easy code:

list_transaction = Observable ([1,2,3]);
list_transaction2 = Observable ([1,2,3]).expand();

In the log :


This is a common problem?

Thanks in advance ! Bye!

This is probably because the reactive operator isn’t evaluated unless the resulting value is consumed somewhere in the UI.

In other words, if your UX actually tries to use list_transaction2 (either directly or through a dependency chain of observables) then it’ll behave exactly as expected.

You can read a bit more about it here