TypeScript: Abort or cancel a scheduled function

Coding
#1

I would like to begin a repeating check until a certain condition is true, so that an event occurs only once after the check passes.

Currently my code looks like this:

Time.scheduleRepeating(() => {
    if (a == b) {
        Debug.log("IT HAS HAPPENED...");
        // CANCEL THIS REPEATING SCHEDULE
    }
}, 0);

So my ideal setup would be, after the message is printed to the log, the repeating schedule is cancelled so that it doesn’t spam the log.

Equally important, I also have the task of cancelling a scheduled function before it executes. For example:

let timedPlatform = Scene.getItem("A1B2C3");

timedPlatform.onCollisionEnter((collider) => {
    Time.schedule(() => {
       Debug.log("Stop standing on me!");
    }, 5);
});
timedPlatform.onCollisionExit((collider) => {
    // CANCEL THE ABOVE TIMED SCHEDULE
});

Unfortunately there seems to be no mention in the API page on how to cancel a repeating schedule.

What is the proper way to cancel a schedule, both non-repeating and repeating?

#2

Have you tried break?

#3

schedule and scheduleRepeating return Dispose object which it meant for such use cases (docs).

For example for the second part of your question you can use something like that:

class PlatformNotificator {
    private disposables: Map<String, Disposable> = new Map()

    onCollisionEnter(collider: BaseItem): void {
        let disposable = Time.schedule(() => {
            Debug.log("Stop standing on me!");
        }, 5);
        this.disposables[collider.id] = disposable

    }

    onCollisionExit(collider: BaseItem): void {
        let disposable = this.disposables[collider.id]
        if (disposable) {
            disposable.dispose()
            this.disposables.delete(collider.id)
        }
    }
} 
let notificator = new PlatformNotificator()
timedPlatform.onCollisionEnter(notificator.onCollisionEnter);
timedPlatform.onCollisionExit(notificator.onCollisionExit);

Note, that I didn’t test it, but this should give you an idea.

For the first part I would recommend you to take a look at observer pattern. Using scheduleRepeating for checking state change is error prone, inefficient and not extensible.

3 Likes
#4

This is very helpful, thank you so much!

I’ll definitely take a look into these types of things, it’s definitely in my interests to make my code work better!