The reorder-list Elements

The reorder-list and reorder-item elements represent an ordered list of items that can be reordered. They are built with accessibility in mind and implement the WAI-ARIA guidelines for rearrangable listboxes.

<reorder-list>
	<reorder-item>Apple</reorder-item>
	<reorder-item>Orange</reorder-item>
	<reorder-item>Banana</reorder-item>
	<reorder-item>Lime</reorder-item>
	<reorder-item>Blueberry</reorder-item>
	<reorder-item>Plum</reorder-item>
</reorder-list>

Installation

You can import through CDN:

<script type="module" src="https://unpkg.com/@auroratide/reorder-list/lib/define.js"></script>

Or, you may install through NPM and include it as part of your build process:

$ npm i @auroratide/reorder-list

import '@auroratide/reorder-list/lib/define.js'

Usage

reorder-list and reorder-item are markup elements that you can use in your HTML document. To use them together, it is best to follow these guidelines:

• reorder-item elements must be direct descendents of a reorder-list element. This is similar to how li must directly descend ol.

Orientation

By default, orientation is "vertical", meaning you drag items up and down. Setting orientation to "horizontal" will allow you to reorder items left and right instead.

<reorder-list orientation="horizontal">
	<reorder-item>Apple</reorder-item>
	<reorder-item>Orange</reorder-item>
	<reorder-item>Banana</reorder-item>
	<reorder-item>Kiwi</reorder-item>
</reorder-list>

Note: Bidirectional reordering is not possible with this component. reorder-list is for lists, whereas bidirectional reordering would be for a grid of some kind; they are different semantics.

Ignoring Reorder Trigger

You may have an element within a reorder-item that you do not want triggering a reorder. For instance, an input element should not start dragging, and it should instead focus on the input.

Use the data-ignore-reorder attribute on any element within reorder-item in order to make that element not start dragging.

<reorder-list>
	<reorder-item>Drag: <input data-ignore-reorder type="text" value="Apple" /></reorder-item>
	<reorder-item>Drag: <input data-ignore-reorder type="text" value="Orange" /></reorder-item>
	<reorder-item>Drag: <input data-ignore-reorder type="text" value="Banana" /></reorder-item>
	<reorder-item>Drag: <input data-ignore-reorder type="text" value="Kiwi" /></reorder-item>
</reorder-list>

CSS Customization

Since these are native custom elements, they can be styled the same way as regular HTML elements.

Of note:

• reorder-item[data-dragging] will style the currently dragged item.

Here's an example of a customized list meant to look like reorderable cards.

reorder-list {
	list-style: none;
	background: #ddd;
	border-radius: 0.5em;
	width: min(400px, 100%);
	padding: 0.5em;
	display: flex;
	flex-direction: column;
	gap: 0.5em;
}

reorder-item {
	background: #fff;
	border-radius: 0.25em;
	padding: 0.5em;
	box-shadow: 0 0.1em 0.15em #0002;
}

reorder-item ul {
	list-style: none;
	display: flex;
	flex-wrap: wrap;
	gap: 0.5em;
	padding: 0;
	margin: 0;
	font-size: 90%;
	color: #2573C1;
}

Events

The reorder-list element dispatches the following events:

| Name | When Triggered | | ------------- | ------------- | | change | Whenever an item in the list is reordered | | commit | At the end of an item being dragged |

Both events contain a reference to the item that was reordered, its previous position in the list, and its new position.

list.addEventListener('change', e => {
	console.log(e.detail.item)
	console.log(e.detail.oldIndex)
	console.log(e.detail.newIndex)
})

The difference between change and commit is the change event happens any time an element changes order, including in the middle of a drag. The commit event only triggers at the end of a drag, so the old index in that event's details will represent the position of that item prior to the drag being started.

Nesting Lists

Nothing stops you from putting lists inside of lists.

<reorder-list orientation="horizontal">
	<reorder-item>
		<strong>Fruit</strong>
		<reorder-list>
			<reorder-item>Apple</reorder-item>
			<reorder-item>Orange</reorder-item>
			<reorder-item>Banana</reorder-item>
			<reorder-item>Kiwi</reorder-item>
		</reorder-list>
	</reorder-item>
	<reorder-item>
		<strong>Vegetable</strong>
		<reorder-list>
			<reorder-item>Tomato</reorder-item>
			<reorder-item>Carrot</reorder-item>
			<reorder-item>Squash</reorder-item>
			<reorder-item>Lettuce</reorder-item>
		</reorder-list>
	</reorder-item>
	<reorder-item>
		<strong>Grain</strong>
		<reorder-list>
			<reorder-item>Wheat</reorder-item>
			<reorder-item>Barley</reorder-item>
			<reorder-item>Rye</reorder-item>
			<reorder-item>Rice</reorder-item>
		</reorder-list>
	</reorder-item>
</reorder-list>

Accessibility

This custom element is build with accessibility in mind! It follows the WAI-ARIA guidelines for rearrangable listboxes (the listbox and option roles).

• When focus enters the list, focus goes to the currently active list item.
• Up and Down can be used to navigate the list, focusing on an element that will be reordered.
• Alt + Up/Down moves the currently selected list item up or down in the order.
• If orientation is horizontal, then Left and Right are used instead.