Svelte MultiSelect
 Svelte MultiSelect

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Keyboard-friendly, accessible and highly customizable multi-select component. View the docs

👇   Examples

selected = []
<script lang="ts">import MultiSelect from '$lib';
import { languages } from '$site/options';
import LanguageSlot from './LanguageSlot.svelte';
let selected;
</script>

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

<MultiSelect
  id="fav-languages"
  options={languages}
  placeholder="Take your pick..."
  bind:selected
  let:idx
  let:option
>
  <LanguageSlot {idx} {option} gap="1ex" />
</MultiSelect>
value = null
<script lang="ts">import MultiSelect from '$lib';
import { ml_libs } from '$site/options';
let value;
let searchText = '';
let loading = false;
let options = ml_libs;
$: if (searchText) {
    loading = true;
    setTimeout(async () => {
        // perform some fetch/database request here to get list of options matching searchText
        // options = await fetch(`https://example.com?search=${searchText}`)
        loading = false;
    }, 1000);
}
</script>

<pre>value = {JSON.stringify(value)}</pre>

<MultiSelect
  id="fav-ml-tool"
  maxSelect={1}
  maxSelectMsg={(current, max) => `${current} of ${max} selected`}
  bind:options
  bind:value
  bind:searchText
  placeholder="Favorite machine learning tool?"
  {loading}
/>
<script lang="ts">import MultiSelect from '$lib';
import { frontend_libs } from '$site/options';
import RepoSlot from './RepoSlot.svelte';
import { Confetti } from 'svelte-zoo';
const frontend_libs_filter_func = (op, searchText) => {
    if (!searchText)
        return true;
    const [label, lang, searchStr] = [op.label, op.lang, searchText].map((s) => s.toLowerCase());
    return label.includes(searchStr) || lang.includes(searchStr);
};
let show_confetti = false;
</script>

<MultiSelect
  id="confetti-select"
  options={frontend_libs}
  maxSelect={4}
  placeholder="Favorite web framework?"
  filterFunc={frontend_libs_filter_func}
  on:add={(e) => {
    if (e.detail.option.label === `Svelte`) {
      show_confetti = true
      setTimeout(() => (show_confetti = false), 3000)
    }
  }}
>
  <RepoSlot let:idx {idx} let:option {option} slot="option" />
</MultiSelect>
{#if show_confetti}
  <Confetti />
{/if}
(due to passing required=true here, form submission will abort if Multiselect is empty)

Also sets allowUserOptions="append" to allow adding custom colors.

<script lang="ts">import MultiSelect from '$lib';
import { colors } from '$site/options';
import ColorSlot from './ColorSlot.svelte';
let selected;
</script>

<form
  on:submit|preventDefault={() => {
    alert(`You selected '${selected.join(`, `)}'`)
  }}
>
  <MultiSelect
    id="color-select"
    options={colors}
    bind:selected
    placeholder="Pick some colors..."
    allowUserOptions="append"
    required
    let:idx
    let:option
  >
    <ColorSlot {idx} {option} />
  </MultiSelect>
  <button>submit</button>
  (due to passing <code>required={true}</code> here, form submission will abort if
  Multiselect is empty)
  <p>
    Also sets
    <code>allowUserOptions="append"</code> to allow adding custom colors.
  </p>
</form>
<script lang="ts">import MultiSelect from '$lib';
import { countries } from '$site/options';
let selected;
// required={1} means form validation will prevent submission if no option selected
let maxOptions = 10;
</script>

<MultiSelect
  id="countries"
  options={countries}
  required={1}
  minSelect={1}
  maxSelect={1}
  {maxOptions}
  selected={[`Canada`]}
/>

<label>
  maxOptions <input type="range" min=0 max={30} bind:value={maxOptions}>
  {maxOptions} <small>(0 means no limit)</small>
</label>

💡   Features

📝   More examples

Some more in-depth examples for specific features of svelte-multiselect:

🧪   Coverage

Statements Branches Lines
Statements Branches Lines

📜   Breaking changes

🔨   Installation

npm install --dev svelte-multiselect
pnpm add -D svelte-multiselect
yarn add --dev svelte-multiselect

📙   Usage

<script>
  import MultiSelect from 'svelte-multiselect'

  const ui_libs = [`Svelte`, `React`, `Vue`, `Angular`, `...`]

  let selected = []
</script>

Favorite Frontend Tools?

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

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

🔣   Props

Full list of props/bindable variables for this component. The Option type you see below is defined in src/lib/index.ts and can be imported as import { type Option } from 'svelte-multiselect'.

  1. activeIndex: number | null = null

    Zero-based index of currently active option in the array of currently matching options, i.e. if the user typed a search string into the input and only a subset of options match, this index refers to the array position of the matching subset of options

  2. activeOption: Option | null = null

    Currently active option, i.e. the one the user currently hovers or navigated to with arrow keys.

  3. createOptionMsg: string | null = `Create this option...`

    The message shown to users when allowUserOptions is truthy and they entered text that doesn’t match any existing options to suggest creating a new option from the entered text. Emits console.error if allowUserOptions is true or 'append' and createOptionMsg='' to since users might be unaware they can create new option. The error can be silenced by setting createOptionMsg=null indicating developer intent is to e.g. use MultiSelect as a tagging component where a user message might be unwanted.

  4. allowEmpty: boolean = false

    Whether to console.error if dropdown list of options is empty. allowEmpty={false} will suppress errors. allowEmpty={true} will report a console error if component is not disabled, not in loading state and doesn’t allowUserOptions.

  5. allowUserOptions: boolean | 'append' = false

    Whether users can enter values that are not in the dropdown list. true means add user-defined options to the selected list only, 'append' means add to both options and selected. If allowUserOptions is true or 'append' then the type object | number | string of entered value is determined by typeof options[0] (i.e. the first option in the dropdown list) to keep type homogeneity.

  6. autocomplete: string = `off`

    Applied to the <input>. Specifies if browser is permitted to auto-fill this form field. Should usually be one of 'on' or 'off' but see MDN docs for other admissible values.

  7. autoScroll: boolean = true

    false disables keeping the active dropdown items in view when going up/down the list of options with arrow keys.

  8. breakpoint: number = 800

    Screens wider than breakpoint in pixels will be considered 'desktop', everything narrower as 'mobile'.

  9. defaultDisabledTitle: string = `This option is disabled`

    Title text to display when user hovers over a disabled option. Each option can override this through its disabledTitle attribute.

  10. disabled: boolean = false

    Disable the component. It will still be rendered but users won’t be able to interact with it.

  11. disabledInputTitle: string = `This input is disabled`

    Tooltip text to display on hover when the component is in disabled state.

  12. duplicates: boolean = false

    Whether to allow users to select duplicate options. Applies only to the selected item list, not the options dropdown. Keeping that free of duplicates is left to developer. The selected item list can have duplicates if allowUserOptions is truthy, duplicates is true and users create the same option multiple times. Use duplicateOptionMsg to customize the message shown to user if duplicates is false and users attempt this and key to customize when a pair of options is considered equal.

  13. duplicateOptionMsg: string = `This option is already selected`

    Text to display to users when allowUserOptions is truthy and they try to create a new option that’s already selected.

  1. key: (opt: T) => unknown = (opt) => `${get_label(opt)}`.toLowerCase()

    A function that maps options to a value by which equality of options is determined. Defaults to mapping options to their lower-cased label. E.g. by default const opt1 = { label: `foo`, id: 1 } and const opt2 = { label: `foo`, id: 2 } are considered equal. If you want to consider them different, you can set key to e.g. key={(opt) => opt.id} or key={(opt) => `${opt.label}-${opt.id}} or even key={JSON.stringify}.

  2. filterFunc = (opt: Option, searchText: string): boolean => {
      if (!searchText) return true
      return `${get_label(opt)}`.toLowerCase().includes(searchText.toLowerCase())
    }

    Customize how dropdown options are filtered when user enters search string into <MultiSelect />. Defaults to:

  3. closeDropdownOnSelect: boolean | 'desktop' = `desktop`

    One of true, false or 'desktop'. Whether to close the dropdown list after selecting a dropdown item. If true, component will loose focus and dropdown is closed. 'desktop' means false if current window width is larger than the current value of breakpoint prop (default is 800, meaning screen width in pixels). This is to align with the default behavior of many mobile browsers like Safari which close dropdowns after selecting an option while desktop browsers facilitate multi-selection by leaving dropdowns open.

  4. form_input: HTMLInputElement | null = null

    Handle to the <input> DOM node that’s responsible for form validity checks and passing selected options to form submission handlers. Only available after component mounts (null before then).

  5. highlightMatches: boolean = true

    Whether to highlight text in the dropdown options that matches the current user-entered search query. Uses the CSS Custom Highlight API with limited browser support (70% as of May 2023) and styling options. See ::highlight(sms-search-matches) below for available CSS variables.

  6. id: string | null = null

    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.

  7. input: HTMLInputElement | null = null

    Handle to the <input> DOM node. Only available after component mounts (null before then).

  8. inputmode: string | null = null

    The inputmode attribute hints at the type of data the user may enter. Values like 'numeric' | 'tel' | 'email' allow mobile browsers to display an appropriate virtual on-screen keyboard. See MDN for details. If you want to suppress the on-screen keyboard to leave full-screen real estate for the dropdown list of options, set inputmode="none".

  9. invalid: boolean = false

    If required = true, 1, 2, ... and user tries to submit form but selected = [] is empty/selected.length < required, invalid is automatically set to true and CSS class invalid applied to the top-level div.multiselect. invalid class is removed as soon as any change to selected is registered. invalid can also be controlled externally by binding to it <MultiSelect bind:invalid /> and setting it to true based on outside events or custom validation.

  10. loading: boolean = false

    Whether the component should display a spinner to indicate it’s in loading state. Use <slot name='spinner'> to specify a custom spinner.

  11. matchingOptions: Option[] = []

    List of options currently displayed to the user. Same as options unless the user entered searchText in which case this array contains only those options for which filterFunc = (op: Option, searchText: string) => boolean returned true.

  12. maxOptions: number | undefined = undefined

    Positive integer to limit the number of options displayed in the dropdown. undefined and 0 mean no limit.

  13. maxSelect: number | null = null

    Positive integer to limit the number of options users can pick. null means no limit. maxSelect={1} will change the type of selected to be a single Option (or null) (not a length-1 array). Likewise, the type of selectedLabels changes from (string | number)[] to string | number | null and selectedValues from unknown[] to unknown | null. maxSelect={1} will also give div.multiselect a class of single. I.e. you can target the selector div.multiselect.single to give single selects a different appearance from multi selects.

  14. maxSelectMsg: ((current: number, max: number) => string) | null = (
      current: number,
      max: number
    ) => (max > 1 ? `${current}/${max}` : ``)

    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}`

    Use CSS selector span.max-select-msg (or prop maxSelectMsgClass if you’re using a CSS framework like Tailwind) to customize appearance of the message container.

  15. minSelect: number | null = null

    Conditionally render the x button which removes a selected option depending on the number of selected options. Meaning all remove buttons disappear if selected.length <= minSelect. E.g. if 2 options are selected and minSelect={3}, users will not be able to remove any selections until they selected more than 3 options.

    Note: Prop required={3} should be used instead if you only care about the component state at form submission time. minSelect={3} should be used if you want to place constraints on component state at all times.

  16. name: string | null = null

    Applied to the <input> element. Sets the key of this field in a submitted form data object. See form example.

  17. noMatchingOptionsMsg: string = `No matching options`

    What message to show if no options match the user-entered search string.

  18. open: boolean = false

    Whether the dropdown list is currently visible. Is two-way bindable, i.e. can be used for external control of when the options are visible.

  19. options: Option[]

    The only required prop (no default). Array of strings/numbers or Option objects to be listed in the dropdown. The only required key on objects is label which must also be unique. An object’s value defaults to label if undefined. You can add arbitrary additional keys to your option objects. A few keys like preselected and title have special meaning though. See type ObjectOption in src/lib/index.ts for all special keys and their purpose.

  20. outerDiv: HTMLDivElement | null = null

    Handle to outer <div class="multiselect"> that wraps the whole component. Only available after component mounts (null before then).

  21. parseLabelsAsHtml: boolean = false

    Whether option labels should be passed to Svelte’s @html directive or inserted into the DOM as plain text. true will raise an error if allowUserOptions is also truthy as it makes your site susceptible to cross-site scripting (XSS) attacks.

  22. pattern: string | null = null

    The pattern attribute specifies a regular expression which the input’s value must match. If a non-null value doesn’t match the pattern regex, the read-only patternMismatch property will be true. See MDN for details.

  23. placeholder: string | null = null

    String shown in the text input when no option is selected.

  24. removeAllTitle: string = `Remove all`

    Title text to display when user hovers over remove-all button.

  25. removeBtnTitle: string = `Remove`

    Title text to display when user hovers over button to remove selected option (which defaults to a cross icon).

  26. required: boolean | number = false

    If required = true, 1, 2, ... forms can’t be submitted without selecting given number of options. true means 1. false means even empty MultiSelect will pass form validity check. If user tries to submit a form containing MultiSelect with less than the required number of options, submission is aborted, MultiSelect scrolls into view and shows message “Please select at least required options”.

  27. resetFilterOnAdd: boolean = true

    Whether text entered into the input to filter options in the dropdown list is reset to empty string when user selects an option.

  28. searchText: string = ``

    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.

  29. selected: Option[] =
     options
       ?.filter((op) => (op as ObjectOption)?.preselected)
       .slice(0, maxSelect ?? undefined) ?? []

    Array of currently selected options. Supports 2-way binding bind:selected={[1, 2, 3]} to control component state externally. Can be passed as prop to set pre-selected options that will already be populated when component mounts before any user interaction.

  30. sortSelected: boolean | ((op1: Option, op2: Option) => number) = false

    Default behavior is to render selected items in the order they were chosen. sortSelected={true} uses default JS array sorting. A compare function enables custom logic for sorting selected options. See the /sort-selected example.

  31. selectedOptionsDraggable: boolean = !sortSelected

    Whether selected options are draggable so users can change their order.

  32. value: Option | Option[] | null = null

    If maxSelect={1}, value will be the single item in selected (or null if selected is empty). If maxSelect != 1, maxSelect and selected are equal. Warning: Setting value does not rendered state on initial mount, meaning bind:value will update local variable value whenever internal component state changes but passing a value when component first mounts won’t be reflected in UI. This is because the source of truth for rendering is bind:selected. selected is reactive to value internally but only on reassignment from initial value. Suggestions for better solutions than #249 welcome!

🎰   Slots

MultiSelect.svelte accepts the following named slots:

  1. slot="option": Customize rendering of dropdown options. Receives as props an option and the zero-indexed position (idx) it has in the dropdown.
  2. slot="selected": Customize rendering of selected items. Receives as props an option and the zero-indexed position (idx) it has in the list of selected items.
  3. slot="spinner": Custom spinner component to display when in loading state. Receives no props.
  4. slot="disabled-icon": Custom icon to display inside the input when in disabled state. Receives no props. Use an empty <span slot="disabled-icon" /> or div to remove the default disabled icon.
  5. slot="expand-icon": Allows setting a custom icon to indicate to users that the Multiselect text input field is expandable into a dropdown list. Receives prop open: boolean which is true if the Multiselect dropdown is visible and false if it’s hidden.
  6. slot="remove-icon": Custom icon to display as remove button. Will be used both by buttons to remove individual selected options and the ‘remove all’ button that clears all options at once. Receives no props.
  7. slot="user-msg": Displayed like a dropdown item when the list is empty and user is allowed to create custom options based on text input (or if the user’s text input clashes with an existing option). Receives props:
    • searchText: The text user typed into search input.
    • msgType: false | 'create' | 'dupe' | 'no-match': 'dupe' means user input is a duplicate of an existing option. 'create' means user is allowed to convert their input into a new option not previously in the dropdown. 'no-match' means user input doesn’t match any dropdown items and users are not allowed to create new options. false means none of the above.
    • msg: Will be duplicateOptionMsg or createOptionMsg (see props) based on whether user input is a duplicate or can be created as new option. Note this slot replaces the default UI for displaying these messages so the slot needs to render them instead (unless purposely not showing a message).
  8. slot='after-input': Placed after the search input. For arbitrary content like icons or temporary messages. Receives props selected: Option[], disabled: boolean, invalid: boolean, id: string | null, placeholder: string, open: boolean, required: boolean. Can serve as a more dynamic, more customizable alternative to the placeholder prop.

Example using several slots:

<MultiSelect options={[`Red`, `Green`, `Blue`, `Yellow`, `Purple`]} let:idx let:option>
   <!-- default slot overrides rendering of both dropdown-listed and selected options -->
  <span>
    {idx + 1}
    {option.label}
    <span style:background={option.label} style=" width: 1em; height: 1em;" />
  </span>

  <CustomSpinner slot="spinner">
  <strong slot="remove-icon">X</strong>
</MultiSelect>

🎬   Events

MultiSelect.svelte dispatches the following events:

  1. on:add={(event) => console.log(event.detail.option)}

    Triggers when a new option is selected.

  2. on:remove={(event) => console.log(event.detail.option)}`

    Triggers when one selected option provided as event.detail.option is removed.

  3. on:removeAll={(event) => console.log(event.detail.options)}`

    Triggers when all selected options are removed. The payload event.detail.options gives the options that were previously selected.

  4. on:change={(event) => console.log(`${event.detail.type}: '${event.detail.option}'`)}

    Triggers when an option is either added or removed, or all options are removed at once. type is one of 'add' | 'remove' | 'removeAll' and payload will be option: Option or options: Option[], respectively.

  5. on:open={(event) => console.log(`Multiselect dropdown was opened by ${event}`)}

    Triggers when the dropdown list of options appears. Event is the DOM’s FocusEvent,KeyboardEvent or ClickEvent that initiated this Svelte dispatch event.

  6. on:close={(event) => console.log(`Multiselect dropdown was closed by ${event}`)}

    Triggers when the dropdown list of options disappears. Event is the DOM’s FocusEvent, KeyboardEvent or ClickEvent that initiated this Svelte dispatch event.

For example, here’s how you might annoy your users with an alert every time one or more options are added or removed:

<MultiSelect
  on:change={(e) => {
    if (e.detail.type === 'add') alert(`You added ${e.detail.option}`)
    if (e.detail.type === 'remove') alert(`You removed ${e.detail.option}`)
    if (e.detail.type === 'removeAll') alert(`You removed ${e.detail.options}`)
  }}
/>

Note: Depending on the data passed to the component the options(s) payload will either be objects or simple strings/numbers.

The above list of events are Svelte dispatch events. This component also forwards many DOM events from the <input> node: blur, change, click, keydown, keyup, mousedown, mouseenter, mouseleave, touchcancel, touchend, touchmove, touchstart. Registering listeners for these events works the same:

<MultiSelect
  options={[1, 2, 3]}
  on:keyup={(event) => console.log('key', event.target.value)}
/>

🦺   TypeScript

The type of options is inferred automatically from the data you pass. E.g.

const options = [
   { label: `foo`, value: 42 }
   { label: `bar`, value: 69 }
]
// type Option = { label: string, value: number }
const options = [`foo`, `bar`]
// type Option = string
const options = [42, 69]
// type Option = number

The inferred type of Option is used to enforce type-safety on derived props like selected as well as slot components. E.g. you’ll get an error when trying to use a slot component that expects a string if your options are objects (see this comment for example screenshots).

You can also import the types this component uses for downstream applications:

import {
  Option,
  ObjectOption,
  DispatchEvents,
  MultiSelectEvents,
} from 'svelte-multiselect'

✨   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. See app.css for how these variables are set on the demo site of this component.

Minimal example that changes 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.

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

<div class="multiselect {outerDivClass}">
  <input class={inputClass} />
  <ul class="selected {ulSelectedClass}">
    <li class={liSelectedClass}>Selected 1</li>
    <li class={liSelectedClass}>Selected 2</li>
  </ul>
  <span class="maxSelectMsgClass">2/5 selected</span>
  <ul class="options {ulOptionsClass}">
    <li class={liOptionClass}>Option 1</li>
    <li class="{liOptionClass} {liActiveOptionClass}">
      Option 2 (currently active)
    </li>
  </ul>
</div>

With global CSS

Odd as it may seem, you get the most fine-grained control over the styling of every part of this component 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 is in its open state. See also simplified DOM structure.

:global(div.multiselect) {
  /* top-level wrapper div */
}
:global(div.multiselect.open) {
  /* top-level wrapper div when dropdown open */
}
:global(div.multiselect.disabled) {
  /* top-level wrapper div when in disabled 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 > input[autocomplete]) {
  /* 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) */
}

🆕   Changelog

View the changelog.

🙏   Contributing

Here are some steps to get you started if you’d like to contribute to this project!