Another Svelte library to detect and deal with your users' idleness.

npm install svelte-idle-sensor
# or
yarn add svelte-idle-sensor
# or
pnpm add svelte-idle-sensor

<script lang="ts">
    import { initializeIdleSensor } from 'svelte-idle-sensor'

    const { idle, reminding, reset } = initializeIdleSensor({
        idleTimeout: 600_000,
        multitabSensor: 'my-app-sensor',
        reminderDuration: 120_000,
        onTabActivity: ({ detail: { isMainTab } }) =>
            isMainTab
                ? resumeExpensiveComputation()
                : pauseExpensiveComputation()
    })
</script>

{#if $idle}
    <LogoutPage />
{:else if $reminding}
    <AreYouStillTherePopup on:confirm={reset}>
{:else}
    <HomePage />
{/if}

or

<script lang="ts">
    import { IdleSensor, idle, reminding, reset } from 'svelte-idle-sensor'
</script>

<IdleSensor 
    idleTimeout={600_000}
    multitabSensor={true}
    reminderDuration={120_000}
    on:tabActivity={hanldeTabActivity}
/>
{#if $idle}
    <LogoutPage />
{:else if $reminding}
    <AreYouStillTherePopup on:confirm={reset}>
{:else}
    <HomePage />
{/if}

Here a Svelte REPL.

You can start the sensor either by calling initializeIdleSensor, or by using the <IdleSensor /> component. Generally, the initialized sensor will start onMount, unless you have set startManually to true in the configuration object (see configuration).

initializeIdleSensor must be called inside a component, but you don't have to wrap it in the component's onMount function, as it will be managed internally by the sensor itself.

Initializing the sensor, will also activate the start, stop and reset functions (see interacting with the sensor). If you don't initialize the sensor, calling them will have no effect.

There can be only one sensor per application, therefore calling initializeIdleSensor or instantiating <IdleSensor /> multiple times in the app, will result in a re-initialization of the same sensor, and not in several sensors running.

// with initializeIdleSensor()
<script>
    import { initializeIdleSensor } from 'svelte-idle-sensor'

    initializeIdleSensor()
</script>

// with <IdleSensor />
<script>
    import { IdleSensor } from 'svelte-idle-sensor'
</script>
<IdleSensor />

The sensor come with a default configuration, which you can personalize on its initialization. You can do it either via a configuration object passed as a parameter to initializeIdleSensor, or via optional props passed to <IdleSensor />. The options, all of which are non-mandatory as they all have a default value, are:

• idleTimeout: number; time of user's inactivity in milliseconds before the idle status changes to idle. This time is extended by the reminderDuration option. Triggering any of the events observed by the sensor (see the option events below), will reset the timer. It defaults to 15 minutes.
• reminderDuration: number; additional time slot after the idle timer expires, before declaring the user idle and calling the idle callback. This is to meet the use case when we may want to prompt the user to check if they are still active before declaring them idle, or to remind them that they will be logged out shortly. Events triggered in this phase won't stop the timer, only the reset and stop methods will (see Interacting with the sensor). It defaults to 0.
• onIdle | on:idle: (idleEvt: CustomEvent<{ lastFiredEvent: Event }>) => void; callback triggered when the user status passes to idle. When invoked, an IdleEvent, storing in its detail the last event fired before the reminding phase, will be passed as a parameter. Events fired in the prompt phase will not call this callback. It defaults to an empty function.
• onRemind | on:remind: (remindEvt: CustomEvent<{ lastFiredEvent: Event }>) => void; when the idleTimeout expires, before declaring the idle status, the remind callback is fired, starting the reminder timer. When invoked, a RemindEvent, storing in its detail the last event fired before the reminding phase, will be passed as a parameter. It defaults to an empty function.
• onActive | on:active: (activityEvt: CustomEvent<{ triggeringEvent: Event }>) => void; callback called when the user resumes activity after having been idle (resuming from the reminding phase doesn't trigger onActive). An ActivityEvent, storing the event that triggered the return to activity in its detail, is passed as a parameter. It defaults to an empty function.
• startManually: boolean; requires the event listeners to be bound manually by using the start method, instead of doing it automatically on the component's mount. It defaults to false.
• events: EventTypeName[]; a list of the DOM events that will be listened to in order to monitor the user's activity. The events must be of EventTypeName type (this type can be imported). The list defaults to ['mousemove', 'keydown', 'wheel', 'resize', 'mousewheel', 'mousedown', 'pointerdown', 'touchstart', 'touchmove', 'visibilitychange']
• multitabSensor: strings; coordinates sensors that are open on different tabs. This configuration option is to meet the case when the user is working on a tab, while another instance of the sensor is running on another one: coordinating the sensors will prevent the inactive tab to fire any idle callback that will affect the tab currently in use too (e.g. disconnecting the user). To activate the option, you have to pass a string (any short key identifying the page/app) that will be used to name the channel (it relies on the BroadcastChannel API under the hood) used by the sensors to communicate. With multitabSensor active, there will be only one active sensor at a time, and it will be the one in the tab the user has most recently interacted with, called the main tab; when another tab becomes the main one, the other sensors are stopped. If a tab becomes the main tab again, its sensor is restarted, unless startManually is set to true. Closing the main tab will result in one of the other tabs being chosen randomly as the main one in about 1.5 seconds (unless any other event occurs meanwhile). Activating this option will make the onTabActivity | on:tabActivity available. It defaults to undefined.
• onTabActivity | on:tabActivity: (tabActivityEvt: CustomEvent<{ isMainTab: boolean }>) => void; callback called when a change of tab is detected (e.g. a new instance of the sensor is open in a different tab). A TabActivityEvent storing an isMainTab: boolean property in its detail, is passed as a parameter. It defaults to an empty function.

To interact with the sensor, in addition to passing different configuration callbacks, idle-sensor provides several stores and methods.

• idle and reminding: Readable<boolean>; these two readable stores report the user status. They do not concur.
• start, stop and reset: () => void; allow respectively to start, stop and reset the sensor. start and reset, create a custom manualstart and manualreset event, that will be stored by stored as lastFiredEvent by the idle and remind events passsed to the onIdle and onRemind callbacks if no other activity occurs (there's another custom event, mount, created when timers start automatically). Finally, stop and reset don't trigger onActive.

These can be imported directly from svelte-idle-sensor, regardless of whether the sensor has been initialized by `` or component. Once the sensor has been initialized, you can import them anywhere in the app and they'll be working, thanks to Svelte stores' properties.

Finally, idle, remind, start, stop, and reset, are also returned by initializeIdleSensor

// named import
<script>
    import { idle, remind, start, stop, reset } from 'svelte-idle-sensor'
    // do something
</script>

// with initializeIdleSensor()
<script>
    import { initializeIdleSensor } from 'svelte-idle-sensor'

    const { idle, remind, start, stop, reset } = initializeIdleSensor()
    // do something
</script>

This library is inspired by react-idle-timer