clearTimer

Cancel a scheduled timer.

import { setTimer, clearTimer, IDL, update } from 'azle';

export default class {
    activeTimers: Set<bigint> = new Set();

    @update([IDL.Nat], IDL.Nat64)
    scheduleTask(delaySeconds: number): bigint {
        const timerId = setTimer(delaySeconds, () => {
            console.log('Task executed!');
            this.activeTimers.delete(timerId);
        });

        this.activeTimers.add(timerId);
        return timerId;
    }

    @update([IDL.Nat64], IDL.Bool)
    cancelTask(timerId: bigint): boolean {
        if (this.activeTimers.has(timerId)) {
            clearTimer(timerId);
            this.activeTimers.delete(timerId);
            return true;
        }
        return false;
    }
}

The clearTimer function cancels a previously scheduled timer (created with either setTimer or setTimerInterval).

Parameters:

• timerId: The timer ID returned by setTimer or setTimerInterval

Returns: void

Important Notes:

• Safe to call with non-existent timer IDs (no error thrown)
• Works for both one-time timers (setTimer) and recurring timers (setTimerInterval)
• Once cleared, the timer ID cannot be reused