Function tokens::on_change

pub fn on_change<TToken, TProducer, TConsumer, TState>(
    producer: TProducer,
    consumer: TConsumer,
    state: Option<Arc<TState>>
) -> impl Subscription
where
    TState: 'static,
    TToken: ChangeToken + 'static,
    TProducer: Fn() -> TToken + Send + Sync + 'static,
    TConsumer: Fn(Option<Arc<TState>>) + Send + Sync + 'static,

Registers a consumer action to be invoked whenever the token produced changes.

Arguments

• producer - The function that produces the change token
• consumer - The function that is called when the change token changes
• state - The optional state supplied to the consumer

Returns

An opaque subscription. When it is dropped, the producer will no longer be polled and the consumer will no longer be notified.