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OverlayScrollbars for Svelte

This is the official OverlayScrollbars Svelte wrapper.

Installation

npm install overlayscrollbars-svelte

Peer Dependencies

OverlayScrollbars for Svelte has the following peer dependencies:

• The vanilla JavaScript library: overlayscrollbars

npm install overlayscrollbars

• The Svelte framework: svelte

npm install svelte

Usage

The first step is to import the CSS file into your app:

import 'overlayscrollbars/overlayscrollbars.css';

Note: If the path 'overlayscrollbars/overlayscrollbars.css' is not working use 'overlayscrollbars/styles/overlayscrollbars.css' as the import path for the CSS file.

Component

The main entry point is the OverlayScrollbarsComponent which can be used in your application as a component:

<script>
import { OverlayScrollbarsComponent } from "overlayscrollbars-svelte";

// ...
</script>

<OverlayScrollbarsComponent defer>
  example content
</OverlayScrollbarsComponent>

Properties

The component accepts all properties of regular elements such as div and span.
Additionally it has custom optional properties:

• element: accepts a string which represents the tag of the root element.
• options: accepts an object which represents the OverlayScrollbars options.
• events: accepts an object which represents the OverlayScrollbars events.
• defer: accepts an boolean or object. Defers the initialization to a point in time when the browser is idle.

Note: Its highly recommended to use the defer option whenever possible to defer the initialization to a browser's idle period.

<!-- example usage -->
<OverlayScrollbarsComponent
  element="span"
  options={{ scrollbars: { autoHide: 'scroll' } }}
  events={{ scroll: () => { /* ... */ } }}
  defer
/>

Events

Additionally to the events property the OverlayScrollbarsComponent emits "native" Svelte events. To prevent name collisions with DOM events the events have a os prefix.

Note: Events are still supported even though they are are deprecated. This was done to ease migration and will be removed in a future release. Please use the events option instead.

<!-- example usage -->
<OverlayScrollbarsComponent
  on:osInitialized={onInitialized}
  on:osUpdated={onUpdated}
  on:osDestroyed={onDestroyed}
  on:osScroll={onScroll}
/>

All events are typed, but you can use the EventListenerArgs type as utility in case its needed:

import type { EventListenerArgs } from 'overlayscrollbars';

// example listener
const onUpdated = (event) => {
  const [instance, onUpdatedArgs] = event.detail as EventListenerArgs['updated'];
}

Ref

The ref of the OverlayScrollbarsComponent will give you an object with which you can access the OverlayScrollbars instance and the root element of the component.
The ref object has two properties:

• osInstance: a function which returns the OverlayScrollbars instance.
• getElement: a function which returns the root element.

Primitive

In case the OverlayScrollbarsComponent is not enough, you can also use the useOverlayScrollbars primitive:

<script>
  import { useOverlayScrollbars } from 'overlayscrollbars-svelte';
  import { onMount } from 'svelte';

  let div = $state();
  let params = $state$({ options, events, defer });
  const [initialize, instance] = useOverlayScrollbars(() => params);

  /** 
   * or:
   * 
   * let options = $state$();
   * let events = $state();
   * let defer = $state();
   * const [initialize, instance] = useOverlayScrollbars({
   *   options: () => options,
   *   events: () => events,
   *   defer: () => defer,
   * });
   * 
   */

  onMount(() => {
    initialize({ target: div });
  });
</script>

<div bind:this={div}></div>

The primitive is for advanced usage and lets you control the whole initialization process. This is useful if you want to integrate it with other plugins.

Parameters

Parameters are optional and similar to the OverlayScrollbarsComponent. Its an object with optional properties:

• options: accepts an object which represents the OverlayScrollbars options.
• events: accepts an object which represents the OverlayScrollbars events.
• defer: accepts an boolean or object. Defers the initialization to a point in time when the browser is idle.

Note: You can also pass a function as parameter which returns the object in case the object itself is reactive. This also applies to all fields.

Return

The useOverlayScrollbars primitive returns a tuple with two values:

• The first value is the initialization function, it takes one argument which is the InitializationTarget.
• The second value is a function which returns the current OverlayScrollbars instance or null if not initialized.

License

MIT

Changelog

0.5.5

The whole package was rewritten to support Svelte 5.

Breaking Changes

• Svelte 5 is now the only supported svelte version. Support for Svelte 4 and Svelte 3 was dropped.

Features

• The OverlayScrollbarsComponent properties are now generic depending on its element type.
• The OverlayScrollbarsComponent now accepts a custom Svelte Component as element.
• The OverlayScrollbarsComponent still supports events even though they are deprecated. This was done to ease migration and will be removed in a future release.
• A new primitive called useOverlayScrollbars which allows for more flexibility in case the OverlayScrollbarsComponent is not enough.

0.5.4

Improvements

• The OverlayScrollbarsComponent now properly supports 'body' as its element tag.

0.5.3

Improvements

• Adapt the exports field in the package.json for correct commonjs and module handling.

0.5.2

Bug Fixes

• Make sure component is stateless and children won't update more often than needed.

0.5.1

• Improve Server Side Rendering behavior by creating additional markup only on the client with the hydration phase.
• Improve deferred initialization where the time between created markup and actual initialization is masked with CSS.

0.5.0

Added the possibility to defer the initialization to a point in time when the browser is idle. (or to the next frame if window.requestIdleCallback is not supported)

• support for svelte v4
• OverlayScrollbarsComponent accepts now the defer property

0.4.0

The component was created.
Depends on OverlayScrollbars version ^2.0.0 and Svelte version ^3.44.0.