Simple Svelte Autocomplete

Autocomplete / Select / Typeahead component made with Svelte

Live demo http://simple-svelte-autocomplete.surge.sh/

no dependencies
use plain lists or array of objects
option to define a label field or function
option to define more fields used for search
support for async load of items

Install

npm i -D simple-svelte-autocomplete

Usage

Import the component and define items:

import AutoComplete from "simple-svelte-autocomplete";

const colors = ["White", "Red", "Yellow", "Green", "Blue", "Black"];
let selectedColor;

And use it like this:

<AutoComplete items={colors} bind:selectedItem={selectedColor} />

You can also use it with array of objects:

const colorList = [
  { id: 1, name: "White", code: "#FFFFFF" },
  { id: 2, name: "Red", code: "#FF0000" },
  { id: 3, name: "Yellow", code: "#FF00FF" },
  { id: 4, name: "Green", code: "#00FF00" },
  { id: 5, name: "Blue", code: "#0000FF" },
  { id: 6, name: "Black", code: "#000000" }
];

let selectedColorObject;

Just define which field should be used as label:

<AutoComplete
  items={colorList}
  bind:selectedItem={selectedColorObject}
  labelFieldName="name" />

Specifying function for label instead of field name is also supported:

<AutoComplete
  items={colorList}
  bind:selectedItem={selectedColorObject}
  labelFunction={color => color.id + '. ' + color.name} />

By default the component searches by the item label, but it can also search by custom fields by specifying keywords function. For example to enable searching by color name and color HEX code:

<AutoComplete
  items={colorList}
  bind:selectedItem={selectedColorObject}
  labelFieldName="name"
  keywordsFunction={color => color.name + ' ' + color.code} />

Asynchronous loading of items

Define a searchFunction which will be called with keyword parameter. If you have searchFunction defined you don't need to specify items since the function will be used for loading. The delay parameter specifies the time to wait between user input and calling the searchFunction. It is recommend that delay > 200ms is set when using a remote search function to avoid sending too many requests. The localSearch parameter can be set to false if the search function already returns filtered items accordind to the user input.

<AutoComplete searchFunction={getItems} delay=200 localSearch=false labelFieldName="name" valueFieldName="id" bind:selectedItem={myValue} />

async function getItems(keyword) {
  const url = '/api/my-items/?format=json&name=' + encodeURIComponent(keyword);

  const response = await fetch(url);
  const json = await response.json();

  return json.results;
}

{
  "results": [
    {
      "id": 1,
      "name": "Sample One",
      "date": "2020-09-25",
    },
    {
      "id": 2,
      "name": "Sample Two",
      "date": "2020-09-26",
    }
  ]
}

Properties

Behaviour

items - array of items the user can select from (optional, use searchFunction for async loading of items)
searchFunction - optional function to load items asynchroniously from HTTP call for example, the searchFunction can also return all items and addtional local search will still be performed
delay - delay in miliseconds to wait after user input to do the local searching or call searchFunction if provided, defaults to 0
localFiltering - boolean specifying if searchFunction is used, to still peform local filtering of the items to only ones that match the user input, defaults to true
selectedItem - the current item that is selected (object if the array of items contains objects)
labelFieldName - the name of the field to be used for showing the items as text in the droprown
keywordsFieldName - the name of the filed to search by
value - derived value from the selectedItem, equals to selectedItem if valueFieldName is not specified
valueFieldName - field to use to derive the value from the selected item
labelFunction - optional function that creates label from the item. If used labelFieldName is ignored
keywordsFunction - optional function that creates text to search from the item. If used keywordsFieldName is ignored
valueFunction - optional function that derives the value from the selected item. If used valueFieldName is ignored
keywordsCleanFunction - optional function to additionally process the derived keywords from the item
textCleanFunction - optional function to additionally process the user entered text
selectFirstIfEmpty - set to true to select the first item if the user clears the text and closes the dropdown. Defaults to false.
minCharactersToSearch - minimum length of search text to perform search, defaults to 1
maxItemsToShowInList - maximum number of items to show in the dropdown list, defaults 0 (no limit)
disabled - disable the control

Events

beforeChange - function called before a new value is selected
onChange - function called after new value is selected

Style and UI options

placeholder - change the text displayed when no option is selected
noResultsText - text to show in the dropdown when the search text does not match any item. Defaults to "No results found". Can be set to "" to not show anything.
hideArrow - set to true to not show the blue dropdown arrow
showClear - set to true to show X button that can be used to deselect the selected item
className - apply a className to the control
inputClassName - apply a className to the input control
inputId - apply an id attribute to the the input control
dropdownClassName - apply a className to the dropdown div showing the list of items
name - generate an HTML input with this name, containing the current value
debug - flag to enable detailed log statements from the component
html5autocomplete - flag to enable or disable the HTML5 autocomplete attribute

UI Slots

item - change the apearance of items in the dropdown list:

<div slot="item" let:item={item} let:label={label}>
  {@html label} <!-- to render the default higliglighted item label -->
  <!-- render anything else -->
  <span style="color:{item.propertyX}">{item.propertyY}</span>
</div>

no-results - customize the div that shows the "no results" text:

<div slot="no-results" let:noResultsText={noResultsText}>
    <span>{noResultsText}</strong>
</pre>

The noResultsText variable is optional and can be ommited.

CSS properties

autocomplete the class applied to the main control
autocomplete-input the class applied to the input list
autocomplete-list the class applied to the dropdown list
autocomplete-list-item the class applied to items in the dropdown list

The component is inteded to use with Bulma but it can be adapted to use Boostrap or anything else.

jarrodmoldrich/simple-svelte-autocomplete