svelte-multiselect

 Svelte MultiSelect

Live demo.

Keyboard-friendly, zero-dependency multi-select Svelte component.

Key features

• Single / multiple select: pass maxSelect={1} prop to only allow one selection
• Dropdowns: scrollable lists for large numbers of options
• Searchable: start typing to filter options
• Tagging: selected options are recorded as tags in the input
• Server-side rendering: no reliance on browser objects like window or document
• Configurable: see props
• No dependencies: needs only Svelte as dev dependency
• Keyboard friendly for mouse-less form completion

Recent breaking changes

• v3.0.0 changed the event.detail payload for 'add', 'remove' and 'change' events from token to option, e.g.

  on:add={(e) => console.log(e.detail.token.label)} // v2.0.0
  on:add={(e) => console.log(e.detail.option.label)} // v3.0.0
  

  It also added a separate event type removeAll for when the user removes all currently selected options at once which previously fired a normal remove. The props ulTokensClass and liTokenClass were renamed to ulSelectedClass and liSelectedClass. Similarly, the CSS variable --sms-token-bg changed to --sms-selected-bg.

• v4.0.0 renamed the slots for customizing how selected options and dropdown list items are rendered:

  • old: <slot name="renderOptions" />, new: <slot name="option" />
  • old: <slot name="renderSelected" />, new: <slot name="selected" />

Installation

yarn add -D svelte-multiselect

Usage

<script>
  import MultiSelect from 'svelte-multiselect'

  const webFrameworks = [
    `Svelte`,
    `React`,
    `Vue`,
    `Angular`,
    `Polymer`,
    `Ruby on Rails`,
    `ASP.net`,
    `Laravel`,
    `Django`,
    `Express`,
    `Spring`,
  ]

  let selected
</script>

Favorite Web Frameworks?

<code>selected = {JSON.stringify(selected)}</code>

<MultiSelect bind:selected options={webFrameworks} />

Props

Full list of props/bindable variables for this component:

name	default	description
options	required prop	Array of strings/numbers or Option objects that will be listed in the dropdown. See src/lib/index.ts for admissible fields. The label is the only mandatory one. It must also be unique.
showOptions	false	Bindable boolean that controls whether the options dropdown is visible.
searchText	``	Text the user-entered to filter down on the list of options. Binds both ways, i.e. can also be used to set the input text.
activeOption	null	Currently active option, i.e. the one the user currently hovers or navigated to with arrow keys.
maxSelect	null	Positive integer to limit the number of options users can pick. null means no limit.
selected	[]	Array of currently/pre-selected options when binding/passing as props respectively.
selectedLabels	[]	Labels of currently selected options.
selectedValues	[]	Values of currently selected options.
noOptionsMsg	'No matching options'	What message to show if no options match the user-entered search string.
readonly	false	Disable the component. It will still be rendered but users won't be able to interact with it.
placeholder	undefined	String shown in the text input when no option is selected.
input	undefined	Handle to the <input> DOM node.
id	undefined	Applied to the <input> element for associating HTML form <label>s with this component for accessibility. Also, clicking a <label> with same for attribute as id will focus this component.
name	id	Applied to the <input> element. If not provided, will be set to the value of id. Sets the key of this field in a submitted form data object. Not useful at the moment since the value is stored in Svelte state, not on the <input>.
required	false	Whether forms can be submitted without selecting any options. Aborts submission, is scrolled into view and shows help "Please fill out" message when true and user tries to submit with no options selected.
autoScroll	true	false disables keeping the active dropdown items in view when going up/down the list of options with arrow keys.
allowUserOptions	false	Whether users are allowed to enter values not in the dropdown list. true means add user-defined options to the selected list only, 'append' means add to both options and selected.
loading	false	Whether the component should display a spinner to indicate it's in loading state. Use <slot name='spinner'> to specify a custom spinner.

Exposed methods

1. filterFunc = (op: Option, searchText: string) => boolean: Determine what options are shown when user enters search string to filter dropdown list. Defaults to:

   filterFunc = (op: Option, searchText: string) => {
     if (!searchText) return true
     return `${op.label}`.toLowerCase().includes(searchText.toLowerCase())
   }
   

2. maxSelectMsg = (current: number, max: number) => string: Inform users how many of the maximum allowed options they have already selected. Set maxSelectMsg={null} to not show a message. Defaults to null when maxSelect={1} or maxSelect={null}. Else if maxSelect > 1, defaults to:

   maxSelectMsg = (current: number, max: number) => `${current}/${max}`
   

Slots

MultiSelect.svelte has 3 named slots:

• slot="option": Customize rendering of dropdown options. Receives as props the option object and the zero-indexed position (idx) it has in the dropdown.
• slot="selected": Customize rendering selected tags. Receives as props the option object and the zero-indexed position (idx) it has in the list of selected items.
• slot="spinner": Custom spinner component to display when in loading state. Receives no props.

Example:

<MultiSelect options={[`Banana`, `Apple`, `Mango`]}>
  <span let:idx let:option slot="option">
    {idx + 1}. {option.label}
    {option.label === `Mango` ? `🎉` : ``}
  </span>

  <span let:idx let:option slot="selected">
    #{idx + 1}
    {option.label}
  </span>

  <CustomSpinner slot="spinner">
</MultiSelect>

Events

MultiSelect.svelte dispatches the following events:

name	detail	description
add	{ option: Option }	Triggers when a new option is selected.
remove	{ option: Option }	Triggers when one selected option provided as event.detail.option is removed.
removeAll	options: Option[]	Triggers when all selected options are removed. The payload event.detail.options gives the options that were previously selected.
change	{ option?: Option, options?: Option[] }, type: 'add' | 'remove' | 'removeAll'	Triggers when a option is either added or removed, or all options are removed at once.
blur	none	Triggers when the input field looses focus.

Examples

• on:add={(event) => console.log(event.detail.option.label)}
• on:remove={(event) => console.log(event.detail.option.label)}.
• on:change={(event) => console.log(`${event.detail.type}: '${event.detail.option.label}'`)}
• on:blur={yourFunctionHere}

<MultiSelect
  on:change={(e) => alert(`You ${e.detail.type}ed '${e.detail.option.label}'`)}
/>

TypeScript

TypeScript users can import the types used for internal type safety:

<script lang="ts">
  import MultiSelect, {
    Option,
    Primitive,
    ProtoOption,
  } from 'svelte-multiselect'

  const myOptions: Option[] = [
    { label: 'foo', value: 42 },
    { label: 'bar', value: 69 },
  ]
</script>

Styling

There are 3 ways to style this component. To understand which options do what, it helps to keep in mind this simplified DOM structure of the component:

<div class="multiselect">
  <ul class="selected">
    <li>Selected 1</li>
    <li>Selected 2</li>
  </ul>
  <ul class="options">
    <li>Option 1</li>
    <li>Option 2</li>
  </ul>
</div>

With CSS variables

If you only want to make small adjustments, you can pass the following CSS variables directly to the component as props or define them in a :global() CSS context.

• div.multiselect
  • border: var(--sms-border, 1pt solid lightgray): Change this to e.g. to 1px solid red to indicate this form field is in an invalid state.
  • border-radius: var(--sms-border-radius, 5pt)
  • background: var(--sms-input-bg)
  • height: var(--sms-input-height, 2em)
• div.multiselect.open
  • z-index: var(--sms-open-z-index, 4): Increase this if needed to ensure the dropdown list is displayed atop all other page elements.
• div.multiselect:focus-within
  • border: var(--sms-focus-border, 1pt solid var(--sms-active-color, cornflowerblue)): Border when component has focus. Defaults to --sms-active-color if not set which defaults to cornflowerblue.
• div.multiselect.readonly
  • background: var(--sms-readonly-bg, lightgray): Background when in readonly state.
• div.multiselect > ul.selected > li > input
  • color: var(--sms-text-color, inherit): Input text color.
• div.multiselect > ul.selected > li
  • background: var(--sms-selected-bg, var(--sms-active-color, cornflowerblue)): Background of selected options.
  • height: var(--sms-selected-li-height): Height of selected options.
• ul.selected > li button:hover, button.remove-all:hover, button:focus
  • color: var(--sms-remove-x-hover-focus-color, lightskyblue): Color of the cross-icon buttons for removing all or individual selected options when in :focus or :hover state.
• div.multiselect > ul.options
  • background: var(--sms-options-bg, white): Background of dropdown list.
  • max-height: var(--sms-options-max-height, 50vh): Maximum height of options dropdown.
  • overscroll-behavior: var(--sms-options-overscroll, none): Whether scroll events bubble to parent elements when reaching the top/bottom of the options dropdown. See MDN.
  • box-shadow: var(--sms-options-shadow, 0 0 14pt -8pt black);: Box shadow of dropdown list.
• div.multiselect > ul.options > li
  • scroll-margin: var(--sms-options-scroll-margin, 100px): Top/bottom margin to keep between dropdown list items and top/bottom screen edge when auto-scrolling list to keep items in view.
• div.multiselect > ul.options > li.selected
  • border-left: var(--sms-li-selected-border-left, 3pt solid var(--sms-selected-color, green))
  • background: var(--sms-li-selected-bg, inherit): Background of selected list items in options pane.
  • color: var(--sms-li-selected-color, inherit): Text color of selected list items in options pane.
• div.multiselect > ul.options > li:not(.selected):hover
  • border-left: var(--sms-li-not-selected-hover-border-left, 3pt solid var(--sms-active-color, cornflowerblue))
• div.multiselect > ul.options > li.active
  • background: var(--sms-li-active-bg, var(--sms-active-color, cornflowerblue)): Background of active (currently with arrow keys highlighted) list item.
• div.multiselect > ul.options > li.disabled
  • background: var(--sms-li-disabled-bg, #f5f5f6): Background of disabled options in the dropdown list.
  • color: var(--sms-li-disabled-text, #b8b8b8): Text color of disabled option in the dropdown list.

For example, to change the background color of the options dropdown:

<MultiSelect --sms-options-bg="white" />

With CSS frameworks

The second method allows you to pass in custom classes to the important DOM elements of this component to target them with frameworks like Tailwind CSS.

• outerDivClass
• ulSelectedClass
• liSelectedClass
• ulOptionsClass
• liOptionClass
• liActiveOptionClass

This simplified version of the DOM structure of this component shows where these classes are inserted:

<div class="multiselect {outerDivClass}">
  <ul class="selected {ulSelectedClass}">
    <li class={liSelectedClass}>Selected 1</li>
    <li class={liSelectedClass}>Selected 2</li>
  </ul>
  <ul class="options {ulOptionsClass}">
    <li class={liOptionClass}>Option 1</li>
    <li class="{liOptionClass} {liActiveOptionClass}">
      Option 2 (currently active)
    </li>
  </ul>
</div>

Granular control through global CSS

You can alternatively style every part of this component with more fine-grained control by using the following :global() CSS selectors. ul.selected is the list of currently selected options rendered inside the component's input whereas ul.options is the list of available options that slides out when the component has focus.

:global(div.multiselect) {
  /* top-level wrapper div */
}
:global(div.multiselect.open) {
  /* top-level wrapper div when dropdown open */
}
:global(div.multiselect.readonly) {
  /* top-level wrapper div when in readonly state */
}
:global(div.multiselect > ul.selected) {
  /* selected list */
}
:global(div.multiselect > ul.selected > li) {
  /* selected list items */
}
:global(div.multiselect button) {
  /* target all buttons in this component */
}
:global(div.multiselect > ul.selected > li button, button.remove-all) {
  /* buttons to remove a single or all selected options at once */
}
:global(div.multiselect > ul.selected > li > input) {
  /* input inside the top-level wrapper div */
}
:global(div.multiselect > ul.options) {
  /* dropdown options */
}
:global(div.multiselect > ul.options > li) {
  /* dropdown list items */
}
:global(div.multiselect > ul.options > li.selected) {
  /* selected options in the dropdown list */
}
:global(div.multiselect > ul.options > li:not(.selected):hover) {
  /* unselected but hovered options in the dropdown list */
}
:global(div.multiselect > ul.options > li.active) {
  /* active means item was navigated to with up/down arrow keys */
  /* ready to be selected by pressing enter */
}
:global(div.multiselect > ul.options > li.disabled) {
  /* options with disabled key set to true (see props above) */
}

Want to contribute?

To submit a PR, clone the repo, install dependencies and start the dev server to try out your changes.

git clone https://github.com/janosh/svelte-multiselect
cd svelte-multiselect
yarn
yarn dev