The Observer from the Rx pattern is the trio of callbacks that
get subscribed to an Observable for receiving events.
The events received must follow the Rx grammar, which is:
onNext * (onComplete | onError)?
That means an Observer can receive zero or multiple events, the stream
ending either in one or zero onComplete or onError (just one, not both),
and after onComplete or onError, a well behaved Observable implementation
shouldn't send any more onNext events.
The Observer from the Rx pattern is the trio of callbacks that get subscribed to an Observable for receiving events.
The events received must follow the Rx grammar, which is: onNext * (onComplete | onError)?
That means an Observer can receive zero or multiple events, the stream ending either in one or zero
onComplete
oronError
(just one, not both), and after onComplete or onError, a well behaved Observable implementation shouldn't send any more onNext events.