operator_on_next

Invoke a callback for each value that can also decide whether to forward it.

• Returning true allows the value to be forwarded to the destination observer.
• Returning false prevents the value from being forwarded.

Like filter, but with access to the destination observer!

See Also

• TapOperator - Mirror all signals into another observer.
• TapNextOperator - Run a callback for each next value while letting signals pass through.
• OnSubscribeOperator - Run a callback when a subscription is established.
• FinalizeOperator - Execute cleanup when the observable finishes or unsubscribes.

Example

cargo run -p rx_core --example operator_on_next_example

let _subscription = (1..=5)
    .into_observable()
    .on_next(|next, destination| {
        destination.next(next * 99);
        true
    })
    .subscribe(PrintObserver::new("on_next_operator"));

Output:

on_next_operator - next: 99
on_next_operator - next: 1
on_next_operator - next: 198
on_next_operator - next: 2
on_next_operator - next: 297
on_next_operator - next: 3
on_next_operator - next: 396
on_next_operator - next: 4
on_next_operator - next: 495
on_next_operator - next: 5
on_next_operator - completed
on_next_operator - unsubscribed