aria-autocomplete

Aria Autocomplete

Accessible, extensible, plain JavaScript autocomplete with multi-select.

Try out the examples.

Key design goals and features:

• multiple selection
• extensible source options: Array of Strings, Array of Objects, a Function, or an endpoint String
• progressive enhancement: Automatic source building through specifying a <select> as the element, or an element with child checkboxes.
• accessibility: Use of ARIA attributes, custom screen reader announcements, and testing with assistive technologies
• compatibility: Broad browser and device support (IE9+)
• starting values: Automatic selection based on starting values, including for checkboxes, select options, and for async handling.

Built from the ground up for the accessibility, performance, and functionality combination that I couldn't find in any other autocomplete plugins.

The more general aim here was to build upon the brilliant accessibility of GOV.UK's accessible-autocomplete, but with more functionality, a smaller file size, and (in my testing) better performance (and without using Preact).

Installation / usage

NPM and a module system

First install it

npm install aria-autocomplete

Then import it, and call it on an element (ideally a text <input />, but not necessarily...) with a source for your autocomplete options.

import AriaAutocomplete from 'aria-autocomplete';

AriaAutocomplete(document.getElementById('some-element'), {
    source: ArrayOrStringOrFunction,
});

At its core, the autocomplete requires only an element and a source. When the element is an input, its value will be set using the user's selection(s). If a source option isn't provided (is falsy, or an empty Array), and the element is either a <select>, or has child checkboxes, those will be used to build up the source.

AriaAutocomplete(document.getElementById('some-input'), {
    source: ['Afghanistan', 'Albania', 'Algeria', ...more],
});

const select = document.getElementById('some-select');
AriaAutocomplete(select);

const div = document.getElementById('some-div-with-child-checkboxes');
AriaAutocomplete(div);

Plain JavaScript module

You can grab the minified JS from the dist directory, or straight from unpkg:

<script src="https://unpkg.com/aria-autocomplete" type="text/javascript"></script>

Styling Aria Autocomplete

I would encourage you to style it yourself to match your own site or application's design. An example stylesheet is included in the dist directory however which you can copy into your project and import into the browser.

Performance

I wrote this from the ground up largely because I needed an autocomplete with better performance than others I'd tried. I've optimised the JavaScript where I can, but in some browsers the list rendering will still be a hit to performance. In my testing, modern browsers can render huge lists (1000+ items) just fine (on my laptop, averaging 40ms in Chrome, and under 20ms in Firefox).

As we all know however, Internet Explorer sucks. If you need to support Internet Explorer, I suggest using a sensible combination for the delay, maxResults, and possibly minLength options, to prevent the browser from freezing as your users type, and to reduce the rendering impact. Testing on my laptop, the list rendering in IE11 would take on average: 55ms for 250 items, 300ms for 650 items, and over 600ms for 1000 items.

Options

The full list of options, and their defaults:

{
    /**
     * Give the autocomplete a name to be included in form submissions
     * (Instead of using this option, I would advise initialising the autocomplete on
     * an existing input that will be submitted, to also use any existing validation;
     * this approach is also compatible with the control in multiple mode)
     */
    name: string;

    /**
     * Specify source. See examples file for more specific usage.
     * @example ['Afghanistan', 'Albania', 'Algeria', ...more]
     * @example [{ label: 'Afghanistan', value: 'AFG' }, ...more]
     * @example 'https://some-endpoint.somewhere/available'
     * @example (query, render, isFirstCall) => render(arrayToUse)
     * @example (query) => async () => arrayToUse
     */
    source: string[] | any[] | string | Function | Promise<any[]>;

    /**
     * Properties to use for label and value when source is an Array of Objects
     */
    sourceMapping: any = {};

    /**
     * Additional properties to use when searching for a match.
     * `label` will always be used
     */
    alsoSearchIn: string[] = [];

    /**
     * If no exact match is found,
     * create an entry in the options list for the current search text
     */
    create: boolean | ((value: string) => string | object) = false;

    /**
     * Input delay after typing before running a search
     */
    delay: number = 100;

    /**
     * Minimum number of characters to run a search (includes spaces)
     */
    minLength: number = 1;

    /**
     * Maximum number of results to render. Also used in async endpoint URL
     */
    maxResults: number = 9999;

    /**
     * Render a control that triggers showing all options.
     * Runs a search with an empty query: '', and maxResults of 9999
     */
    showAllControl: boolean = false;

    /**
     * Confirm currently active selection when blurring off of the control. If
     * no active selection, will compare current input value against available labels
     */
    confirmOnBlur: boolean = true;

    /**
     * Allow multiple items to be selected
     */
    multiple: boolean = false;

    /**
     * Adjust input width to match its value. This will incur a performance hit
     */
    autoGrow: boolean = false;

    /**
     * Maximum number of items that can be selected in multiple mode
     */
    maxItems: number = 9999;

    /**
     * If initialised element is an input, and in multiple mode,
     * character that separates the selected values e.g. "GLP,ZWE"
     */
    multipleSeparator: string = `,`;

    /**
     * If input is empty and in multiple mode,
     * delete last selected item on backspace
     */
    deleteOnBackspace: boolean = false;

    /**
     * In multiple mode, if more than 1 item is selected,
     * add a button at the beginning of the selected items as a shortcut to delete all
     */
    deleteAllControl: boolean = false;

    /**
     * Text to use in the deleteAllControl
     */
    deleteAllText: string = `Delete all`;

    /**
     * In async mode, parameter to use when adding the input value to the
     * endpoint String. e.g. https://some-endpoint?q=norway&limit=9999
     */
    asyncQueryParam: string = `q`;

    /**
     * In async mode, parameter to use when adding results limit to the
     * endpoint String. e.g. https://some-endpoint?q=norway&limit=9999
     */
    asyncMaxResultsParam: string = `limit`;

    /**
     * Placeholder text to show in generated input
     */
    placeholder: string;

    /**
     * Text to show (and announce to screen readers) if no results found.
     * If empty, the list of options will remain hidden when there are no results
     */
    noResultsText: string = `No results`;

    /**
     * String to prepend to classes for BEM naming
     * e.g. aria-autocomplete__input
     */
    cssNameSpace: string = `aria-autocomplete`;

    /**
     * Custom class name to add to the options list holder
     */
    listClassName: string;

    /**
     * Custom class name to add to the generated input
     */
    inputClassName: string;

    /**
     * Custom class name to add to the component wrapper
     */
    wrapperClassName: string;

    /**
     * Automatically clear the screen reader announcement element after the specified delay
     * Number is in milliseconds. If true, defaults to 5000.
     */
    srAutoClear: boolean | number = 5000;

    /**
     * Screen reader text used in multiple mode for element deletion.
     * Prepended to option label in aria-label attribute e.g. 'delete Canada'
     */
    srDeleteText: string = `delete`;

    /**
     * Screen reader text announced after deletion.
     * Apended to option label e.g. 'Canada deleted'
     */
    srDeletedText: string = `deleted`;

    /**
     * Value for aria-label attribute on the show all control
     */
    srShowAllText: string = `Show all`;

    /**
     * Screen reader text announced after confirming a selection.
     * Appended to option label e.g. 'Canada selected'
     */
    srSelectedText: string = `selected`;

    /**
     * Screen reader explainer added to the list element via aria-label attribute
     */
    srListLabelText: string = `Search suggestions`;

    /**
     * Screen reader description announced when the input receives focus.
     * Only announced when input is empty
     */
    srAssistiveText: string =
        `When results are available use up and down arrows to review and ` +
        `enter to select. Touch device users, explore by touch or with swipe gestures.`;

    /**
     * Screen reader announcement after results are rendered
     */
    srResultsText: (length: number) => string | void = (length: number) =>
        `${length} ${length === 1 ? 'result' : 'results'} available.`;

    /**
     * Callback before a search is performed - receives the input value.
     * Can be used to alter the search value by returning a String
     */
    onSearch: (value: string) => string | void;

    /**
     * Callback before async call is made - receives the URL, and the XHR object.
     * Can be used to format the endpoint URL by returning a String,
     * and for changes to the XHR object.
     * Note: this is before the onload and onerror functions are attached
     * and before the `open` method is called
     */
    onAsyncPrep: (url: string, xhr: XMLHttpRequest, isFirstCall: boolean) => string | void;

    /**
     * Callback before async call is sent - receives the XHR object.
     * Can be used for final changes to the XHR object, such as adding auth headers
     */
    onAsyncBeforeSend: (query: string, xhr: XMLHttpRequest, isFirstCall: boolean) => void;

    /**
     * Callback after async call succeeds, but before results render - receives the xhr object.
     * Can be used to format the results by returning an Array
     */
    onAsyncSuccess: (query: string, xhr: XMLHttpRequest, isFirstCall: boolean) => any[] | void;

    /**
     * Callback after async call completes successfully, and after the results have rendered.
     */
    onAsyncComplete: (query: string, xhr: XMLHttpRequest, isFirstCall: boolean) => void;

    /**
     * Callback if async call fails.
     */
    onAsyncError: (query: string, xhr: XMLHttpRequest, isFirstCall: boolean) => any[] | void;

    /**
     * Callback prior to rendering - receives the options that are going to render.
     * Can be used to format the results by returning an Array
     */
    onResponse: (options: any[]) => any[] | void;

    /**
     * Callback when rendering items in the list - receives the source option.
     * Can be used to format the <li> content by returning a String
     */
    onItemRender: (sourceEntry: any) => string | void;

    /**
     * Callback after selection is made - receives an object with the option details
     */
    onConfirm: (selected: any) => void;

    /**
     * Callback after an autocomplete selection is deleted.
     * Fires in single-select mode when selection is deleted automatically.
     * Fires in multi-select mode when selected is deleted by user action
     */
    onDelete: (deleted: any) => void;

    /**
     * Callback that fires when the selected item(s) changes
     */
    onChange: (selected: any[]) => void;

    /**
     * Callback when the overall component receives focus
     */
    onFocus: (wrapper: HTMLDivElement) => void;

    /**
     * Callback when the overall component loses focus
     */
    onBlur: (wrapper: HTMLDivElement) => void;

    /**
     * Callback when main script processing and initial rendering has finished
     */
    onReady: (wrapper: HTMLDivElement) => void;

    /**
     * Callback when list area closes - receives the list holder element
     */
    onClose: (list: HTMLUListElement) => void;

    /**
     * Callback when list area opens - receives the list holder element
     */
    onOpen: (list: HTMLUListElement) => void;
}

Calling AriaAutocomplete(element, options); returns the API object, which can also be accessed on the element via element.ariaAutocomplete.