wikimedia/mediawiki-core

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resources/src/jquery/jquery.suggestions.js

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/**
 * This plugin provides a generic way to add suggestions to a text box.
 * Provided by the jquery.suggestions ResourceLoader module.
 *
 * Set options:
 *
 *  $( '#textbox' ).suggestions( { option1: value1, option2: value2 } );
 *  $( '#textbox' ).suggestions( option, value );
 *
 * @example
 * // Initialize:
 * mw.loader.using( 'jquery.suggestions' ).then(()=> {
 *  $( '#textbox' ).suggestions();
 * });
 * @memberof jQueryPlugins
 * @method suggestions
 * @return {jQuery}
 *
 * @param {Object} options
 *
 * @param {Function} [options.fetch] Callback that should fetch suggestions and set the suggestions
 *  property. Called in context of the text box.
 * @param {string} options.fetch.query
 * @param {Function} options.fetch.response Callback to receive the suggestions with
 * @param {Array} options.fetch.response.suggestions
 * @param {number} options.fetch.maxRows
 *
 * @param {Function} [options.cancel] Callback function to call when any pending asynchronous
 *  suggestions fetches. Called in context of the text box.
 *
 * @param {Object} [options.special] Set of callbacks for rendering and selecting.
 *
 * @param {Function} options.special.render Called in context of the suggestions-special element.
 * @param {string} options.special.render.query
 * @param {Object} options.special.render.context
 *
 * @param {Function} options.special.select Called in context of the suggestions-result-current element.
 * @param {jQuery} options.special.select.$textbox
 *
 * @param {Object} [options.result] Set of callbacks for rendering and selecting
 *
 * @param {Function} options.result.render Called in context of the suggestions-result element.
 * @param {string} options.result.render.suggestion
 * @param {Object} options.result.render.context
 *
 * @param {Function} options.result.select Called in context of the suggestions-result-current element.
 * @param {jQuery} options.result.select.$textbox
 *
 * @param {Object} [options.update] Set of callbacks for listening to a change in the text input.
 *
 * @param {Function} options.update.before Called right after the user changes the textbox text.
 * @param {Function} options.update.after Called after results are updated either from the cache or
 * the API as a result of the user input.
 *
 * @param {jQuery} [options.$region=this] The element to place the suggestions below and match width of.
 *
 * @param {string[]} [options.suggestions] Array of suggestions to display.
 *
 * @param {number} [options.maxRows=10] Maximum number of suggestions to display at one time.
 *  Must be between 1 and 100.
 *
 * @param {number} [options.delay=120] Number of milliseconds to wait for the user to stop typing.
 *  Must be between 0 and 1200.
 *
 * @param {boolean} [options.cache=false] Whether to cache results from a fetch.
 *
 * @param {number} [options.cacheMaxAge=60000] Number of milliseconds to cache results from a fetch.
 *  Must be higher than 1. Defaults to 1 minute.
 *
 * @param {boolean} [options.submitOnClick=false] Whether to submit the form containing the textbox
 *  when a suggestion is clicked.
 *
 * @param {number} [options.maxExpandFactor=3] Maximum suggestions box width relative to the textbox
 *  width. If set to e.g. 2, the suggestions box will never be grown beyond 2 times the width of
 *  the textbox. Must be higher than 1.
 *
 * @param {string} [options.expandFrom=auto] Which direction to offset the suggestion box from.
 *  Values 'start' and 'end' translate to left and right respectively depending on the directionality
 *   of the current document, according to `$( document.documentElement ).css( 'direction' )`.
 *   Valid values: "left", "right", "start", "end", and "auto".
 *
 * @param {boolean} [options.positionFromLeft] Sets `expandFrom=left`, for backwards
 *  compatibility.
 *
 * @param {boolean} [options.highlightInput=false] Whether to highlight matched portions of the
 *  input or not.
 */

( function () {

    /**
     * Cancel any delayed maybeFetch() call and callback the context so
     * they can cancel any async fetching if they use AJAX or something.
     *
     * @param {Object} context
     */
    function cancel( context ) {
        if ( context.data.timerID !== null ) {
            clearTimeout( context.data.timerID );
        }
        if ( typeof context.config.cancel === 'function' ) {
            context.config.cancel.call( context.data.$textbox );
        }
    }

    /**
     * Hide the element with suggestions and clean up some state.
     *
     * @param {Object} context
     */
    function hide( context ) {
        // Remove any highlights, including on "special" items
        context.data.$container.find( '.suggestions-result-current' ).removeClass( 'suggestions-result-current' );
        // Hide the container
        context.data.$container.hide();
    }

    /**
     * Restore the text the user originally typed in the textbox, before it
     * was overwritten by highlight(). This restores the value the currently
     * displayed suggestions are based on, rather than the value just before
     * highlight() overwrote it; the former is arguably slightly more sensible.
     *
     * @param {Object} context
     */
    function restore( context ) {
        context.data.$textbox.val( context.data.prevText );
    }

    /**
     * @param {Object} context
     */
    function special( context ) {
        // Allow custom rendering - but otherwise don't do any rendering
        if ( typeof context.config.special.render === 'function' ) {
            // Wait for the browser to update the value
            setTimeout( function () {
                // Render special
                var $special = context.data.$container.find( '.suggestions-special' );
                context.config.special.render.call( $special, context.data.$textbox.val(), context );
            }, 1 );
        }
    }

    /**
     * Ask the user-specified callback for new suggestions. Any previous delayed
     * call to this function still pending will be canceled. If the value in the
     * textbox is empty or hasn't changed since the last time suggestions were fetched,
     * this function does nothing.
     *
     * @param {Object} context
     * @param {boolean} delayed Whether or not to delay this by the currently configured amount of time
     */
    function update( context, delayed ) {
        function maybeFetch() {
            if ( typeof context.config.update.before === 'function' ) {
                context.config.update.before.call( context.data.$textbox );
            }

            var val = context.data.$textbox.val(),
                cache = context.data.cache;

            var cacheHit = false;
            // Only fetch if the value in the textbox changed and is not empty, or if the results were hidden
            // if the textbox is empty then clear the result div, but leave other settings intouched
            if ( val.length === 0 ) {
                hide( context );
                context.data.prevText = '';
            } else if (
                val !== context.data.prevText ||
                // eslint-disable-next-line no-jquery/no-sizzle
                !context.data.$container.is( ':visible' )
            ) {
                context.data.prevText = val;
                // Try cache first
                if ( context.config.cache && val in cache ) {
                    if ( mw.now() - cache[ val ].timestamp < context.config.cacheMaxAge ) {
                        context.data.$textbox.suggestions( 'suggestions', cache[ val ].suggestions );
                        if ( typeof context.config.update.after === 'function' ) {
                            context.config.update.after.call( context.data.$textbox, cache[ val ].metadata );
                        }
                        cacheHit = true;
                    } else {
                        // Cache expired
                        delete cache[ val ];
                    }
                }
                if ( !cacheHit && typeof context.config.fetch === 'function' ) {
                    context.config.fetch.call(
                        context.data.$textbox,
                        val,
                        function ( suggestions, metadata ) {
                            suggestions = suggestions.slice( 0, context.config.maxRows );
                            context.data.$textbox.suggestions( 'suggestions', suggestions );
                            if ( typeof context.config.update.after === 'function' ) {
                                context.config.update.after.call( context.data.$textbox, metadata );
                            }
                            if ( context.config.cache ) {
                                cache[ val ] = {
                                    suggestions: suggestions,
                                    metadata: metadata,
                                    timestamp: mw.now()
                                };
                            }
                        },
                        context.config.maxRows
                    );
                }
            }

            // Always update special rendering
            special( context );
        }

        // Cancels any delayed maybeFetch call, and invokes context.config.cancel.
        cancel( context );

        if ( delayed ) {
            // To avoid many started/aborted requests while typing, we're gonna take a short
            // break before trying to fetch data.
            context.data.timerID = setTimeout( maybeFetch, context.config.delay );
        } else {
            maybeFetch();
        }
    }

    /**
     * Highlight a result in the results table
     *
     * @param {Object} context
     * @param {jQuery|string} $result `<tr>` to highlight, or 'prev' or 'next'
     * @param {boolean} updateTextbox If true, put the suggestion in the textbox
     */
    function highlight( context, $result, updateTextbox ) {
        var $selected = context.data.$container.find( '.suggestions-result-current' );
        if ( !$result.get || $selected.get( 0 ) !== $result.get( 0 ) ) {
            if ( $result === 'prev' ) {
                // eslint-disable-next-line no-jquery/no-class-state
                if ( $selected.hasClass( 'suggestions-special' ) ) {
                    $result = context.data.$container.find( '.suggestions-result' ).last();
                } else {
                    $result = $selected.prev();
                    // eslint-disable-next-line no-jquery/no-class-state
                    if ( !( $result.length && $result.hasClass( 'suggestions-result' ) ) ) {
                        // there is something in the DOM between selected element and the wrapper, bypass it
                        $result = $selected.parents( '.suggestions-results > *' ).prev().find( '.suggestions-result' ).eq( 0 );
                    }

                    if ( $selected.length === 0 ) {
                        // we are at the beginning, so lets jump to the last item
                        if ( context.data.$container.find( '.suggestions-special' ).html() !== '' ) {
                            $result = context.data.$container.find( '.suggestions-special' );
                        } else {
                            $result = context.data.$container.find( '.suggestions-results .suggestions-result' ).last();
                        }
                    }
                }
            } else if ( $result === 'next' ) {
                if ( $selected.length === 0 ) {
                    // No item selected, go to the first one
                    $result = context.data.$container.find( '.suggestions-results .suggestions-result' ).first();
                    if ( $result.length === 0 && context.data.$container.find( '.suggestions-special' ).html() !== '' ) {
                        // No suggestion exists, go to the special one directly
                        $result = context.data.$container.find( '.suggestions-special' );
                    }
                } else {
                    $result = $selected.next();
                    // eslint-disable-next-line no-jquery/no-class-state
                    if ( !( $result.length && $result.hasClass( 'suggestions-result' ) ) ) {
                        // there is something in the DOM between selected element and the wrapper, bypass it
                        $result = $selected.parents( '.suggestions-results > *' ).next().find( '.suggestions-result' ).eq( 0 );
                    }

                    // eslint-disable-next-line no-jquery/no-class-state
                    if ( $selected.hasClass( 'suggestions-special' ) ) {
                        $result = $( [] );
                    } else if (
                        $result.length === 0 &&
                        context.data.$container.find( '.suggestions-special' ).html() !== ''
                    ) {
                        // We were at the last item, jump to the specials!
                        $result = context.data.$container.find( '.suggestions-special' );
                    }
                }
            }
            $selected.removeClass( 'suggestions-result-current' );
            $result.addClass( 'suggestions-result-current' );
        }
        if ( updateTextbox ) {
            if ( $result.length === 0 || $result.is( '.suggestions-special' ) ) {
                restore( context );
            } else {
                context.data.$textbox.val( $result.data( 'text' ) );
                // .val() doesn't call any event handlers, so
                // let the world know what happened
                context.data.$textbox.trigger( 'change' );
            }
            context.data.$textbox.trigger( 'change' );
        }
    }

    /**
     * Sets the value of a property, and updates the widget accordingly
     *
     * @param {Object} context
     * @param {string} property Name of property
     * @param {any} value Value to set property with
     */
    function configure( context, property, value ) {

        // Validate creation using fallback values
        switch ( property ) {
            case 'fetch':
            case 'cancel':
            case 'special':
            case 'result':
            case 'update':
            case '$region':
            case 'expandFrom':
                context.config[ property ] = value;
                break;
            case 'suggestions':
                context.config[ property ] = value;
                // Update suggestions
                if ( context.data !== undefined ) {
                    if ( context.data.$textbox.val().length === 0 ) {
                        // Hide the div when no suggestion exist
                        hide( context );
                    } else {
                        // Rebuild the suggestions list
                        context.data.$container.show();
                        // Update the size and position of the list
                        var regionIsFixed = ( function () {
                            var $el = context.config.$region;
                            do {
                                if ( $el.css( 'position' ) === 'fixed' ) {
                                    return true;
                                }
                                $el = $( $el[ 0 ].offsetParent );
                            } while ( $el.length );
                            return false;
                        }() );
                        var regionPosition = regionIsFixed ?
                            context.config.$region[ 0 ].getBoundingClientRect() :
                            context.config.$region.offset();
                        var newCSS = {
                            position: regionIsFixed ? 'fixed' : 'absolute',
                            top: regionPosition.top + context.config.$region.outerHeight(),
                            bottom: 'auto',
                            width: context.config.$region.outerWidth(),
                            height: 'auto'
                        };

                        // Process expandFrom, after this it is set to left or right.
                        context.config.expandFrom = ( function ( expandFrom ) {
                            var regionWidth, docWidth, regionCenter, docCenter,
                                isRTL = $( document.documentElement ).css( 'direction' ) === 'rtl',
                                $region = context.config.$region;

                            // Backwards compatible
                            if ( context.config.positionFromLeft ) {
                                expandFrom = 'left';

                            // Catch invalid values, default to 'auto'
                            } else if ( [ 'left', 'right', 'start', 'end', 'auto' ].indexOf( expandFrom ) === -1 ) {
                                expandFrom = 'auto';
                            }

                            if ( expandFrom === 'auto' ) {
                                if ( $region.data( 'searchsuggest-expand-dir' ) ) {
                                    // If the markup explicitly contains a direction, use it.
                                    expandFrom = $region.data( 'searchsuggest-expand-dir' );
                                } else {
                                    regionWidth = $region.outerWidth();
                                    docWidth = $( document ).width();
                                    if ( regionWidth > ( 0.85 * docWidth ) ) {
                                        // If the input size takes up more than 85% of the document horizontally
                                        // expand the suggestions to the writing direction's native end.
                                        expandFrom = 'start';
                                    } else {
                                        // Calculate the center points of the input and document
                                        regionCenter = regionPosition.left + regionWidth / 2;
                                        docCenter = docWidth / 2;
                                        if ( Math.abs( regionCenter - docCenter ) < ( 0.10 * docCenter ) ) {
                                            // If the input's center is within 10% of the document center
                                            // use the writing direction's native end.
                                            expandFrom = 'start';
                                        } else {
                                            // Otherwise expand the input from the closest side of the page,
                                            // towards the side of the page with the most free open space
                                            expandFrom = regionCenter > docCenter ? 'right' : 'left';
                                        }
                                    }
                                }
                            }

                            if ( expandFrom === 'start' ) {
                                expandFrom = isRTL ? 'right' : 'left';

                            } else if ( expandFrom === 'end' ) {
                                expandFrom = isRTL ? 'left' : 'right';
                            }

                            return expandFrom;

                        }( context.config.expandFrom ) );

                        if ( context.config.expandFrom === 'left' ) {
                            // Expand from left
                            newCSS.left = regionPosition.left;
                            newCSS.right = 'auto';
                        } else {
                            // Expand from right
                            newCSS.left = 'auto';
                            newCSS.right = document.documentElement.clientWidth -
                                ( regionPosition.left + context.config.$region.outerWidth() );
                        }

                        context.data.$container.css( newCSS );
                        var $results = context.data.$container.children( '.suggestions-results' );
                        $results.empty();
                        var expWidth = -1;
                        for ( var i = 0; i < context.config.suggestions.length; i++ ) {
                            var text = context.config.suggestions[ i ];
                            var $result = $( '<div>' )
                                .addClass( 'suggestions-result' )
                                .attr( 'rel', i )
                                .data( 'text', context.config.suggestions[ i ] )
                                .on( 'mousemove', function () {
                                    context.data.selectedWithMouse = true;
                                    highlight(
                                        context,
                                        $( this ).closest( '.suggestions-results .suggestions-result' ),
                                        false
                                    );
                                } )
                                .appendTo( $results );
                            // Allow custom rendering
                            if ( typeof context.config.result.render === 'function' ) {
                                context.config.result.render.call( $result, context.config.suggestions[ i ], context );
                            } else {
                                $result.text( text );
                            }

                            if ( context.config.highlightInput ) {
                                $result.highlightText( context.data.prevText, { method: 'prefixPlusComboHighlight' } );
                            }

                            // Widen results box if needed (new width is only calculated here, applied later).

                            // The monstrosity below accomplishes two things:
                            // * Wraps the text contents in a DOM element, so that we can know its width. There is
                            //   no way to directly access the width of a text node, and we can't use the parent
                            //   node width as it has text-overflow: ellipsis; and overflow: hidden; applied to
                            //   it, which trims it to a smaller width.
                            // * Temporarily applies position: absolute; to the wrapper to pull it out of normal
                            //   document flow. Otherwise the CSS text-overflow: ellipsis; and overflow: hidden;
                            //   rules would cause some browsers (at least all versions of IE from 6 to 11) to
                            //   still report the "trimmed" width. This should not be done in regular CSS
                            //   stylesheets as we don't want this rule to apply to other <span> elements, like
                            //   the ones generated by jquery.highlightText.
                            var $spanForWidth = $result.wrapInner( '<span>' ).children();
                            var childrenWidth = $spanForWidth.css( 'position', 'absolute' ).outerWidth();
                            $spanForWidth.contents().unwrap();

                            if ( childrenWidth > $result.width() && childrenWidth > expWidth ) {
                                // factor in any padding, margin, or border space on the parent
                                expWidth = childrenWidth + ( context.data.$container.width() - $result.width() );
                            }
                        }

                        // Apply new width for results box, if any
                        if ( expWidth > context.data.$container.width() ) {
                            var maxWidth = context.config.maxExpandFactor * context.data.$textbox.width();
                            context.data.$container.width( Math.min( expWidth, maxWidth ) );
                        }
                    }
                }
                break;
            case 'maxRows':
                context.config[ property ] = Math.max( 1, Math.min( 100, value ) );
                break;
            case 'delay':
                context.config[ property ] = Math.max( 0, Math.min( 1200, value ) );
                break;
            case 'cacheMaxAge':
                context.config[ property ] = Math.max( 1, value );
                break;
            case 'maxExpandFactor':
                context.config[ property ] = Math.max( 1, value );
                break;
            case 'cache':
            case 'submitOnClick':
            case 'positionFromLeft':
            case 'highlightInput':
                context.config[ property ] = !!value;
                break;
        }
    }

    /**
     * Respond to keypress event
     *
     * @param {jQuery.Event} e
     * @param {Object} context
     * @param {number} key Code of key pressed
     */
    function keypress( e, context, key ) {
        // eslint-disable-next-line no-jquery/no-sizzle
        var wasVisible = context.data.$container.is( ':visible' ),
            preventDefault = false;

        switch ( key ) {
            // Arrow down
            case 40:
                if ( wasVisible ) {
                    highlight( context, 'next', true );
                    context.data.selectedWithMouse = false;
                } else {
                    update( context, false );
                }
                preventDefault = true;
                break;
            // Arrow up
            case 38:
                if ( wasVisible ) {
                    highlight( context, 'prev', true );
                    context.data.selectedWithMouse = false;
                }
                preventDefault = wasVisible;
                break;
            // Escape
            case 27:
                hide( context );
                restore( context );
                cancel( context );
                context.data.$textbox.trigger( 'change' );
                preventDefault = wasVisible;
                break;
            // Enter
            case 13:
                preventDefault = wasVisible;
                var $selected = context.data.$container.find( '.suggestions-result-current' );
                hide( context );
                if ( $selected.length === 0 || context.data.selectedWithMouse ) {
                    // If nothing is selected or if something was selected with the mouse
                    // cancel any current requests and allow the form to be submitted
                    // (simply don't prevent default behavior).
                    cancel( context );
                    preventDefault = false;
                } else if ( $selected.is( '.suggestions-special' ) ) {
                    if ( typeof context.config.special.select === 'function' ) {
                        // Allow the callback to decide whether to prevent default or not
                        if ( context.config.special.select.call( $selected, context.data.$textbox, 'keyboard' ) === true ) {
                            preventDefault = false;
                        }
                    }
                } else {
                    if ( typeof context.config.result.select === 'function' ) {
                        // Allow the callback to decide whether to prevent default or not
                        if ( context.config.result.select.call( $selected, context.data.$textbox, 'keyboard' ) === true ) {
                            preventDefault = false;
                        }
                    }
                }
                break;
            default:
                update( context, true );
                break;
        }
        if ( preventDefault ) {
            e.preventDefault();
            e.stopPropagation();
        }
    }

    // See file header for method documentation
    $.fn.suggestions = function () {
        // Multi-context fields
        var args = arguments;

        $( this ).each( function () {
            /* Construction and Loading */

            var context = $( this ).data( 'suggestions-context' );
            if ( context === undefined || context === null ) {
                context = {
                    config: {
                        fetch: function () {},
                        cancel: function () {},
                        special: {},
                        result: {},
                        update: {},
                        $region: $( this ),
                        suggestions: [],
                        maxRows: 10,
                        delay: 120,
                        cache: false,
                        cacheMaxAge: 60000,
                        submitOnClick: false,
                        maxExpandFactor: 3,
                        expandFrom: 'auto',
                        highlightInput: false
                    }
                };
            }

            /* API */

            // Handle various calling styles
            if ( args.length > 0 ) {
                if ( typeof args[ 0 ] === 'object' ) {
                    // Apply set of properties
                    for ( var key in args[ 0 ] ) {
                        configure( context, key, args[ 0 ][ key ] );
                    }
                } else if ( typeof args[ 0 ] === 'string' ) {
                    if ( args.length > 1 ) {
                        // Set property values
                        configure( context, args[ 0 ], args[ 1 ] );
                    }
                }
            }

            /* Initialization */

            if ( context.data === undefined ) {
                context.data = {
                    // ID of running timer
                    timerID: null,

                    // Text in textbox when suggestions were last fetched
                    prevText: null,

                    // Cache of fetched suggestions
                    cache: Object.create( null ),

                    // Number of results visible without scrolling
                    visibleResults: 0,

                    // Suggestion the last mousedown event occurred on
                    $mouseDownOn: $( [] ),
                    $textbox: $( this ),
                    selectedWithMouse: false
                };

                context.data.$container = $( '<div>' )
                    .css( 'display', 'none' )
                    .addClass( 'suggestions' )
                    .append(
                        $( '<div>' ).addClass( 'suggestions-results' )
                            // Can't use click() because the container div is hidden when the
                            // textbox loses focus. Instead, listen for a mousedown followed
                            // by a mouseup on the same div.
                            .on( 'mousedown', function ( e ) {
                                context.data.$mouseDownOn = $( e.target ).closest( '.suggestions-results .suggestions-result' );
                            } )
                            .on( 'mouseup', function ( e ) {
                                var $result = $( e.target ).closest( '.suggestions-results .suggestions-result' ),
                                    $other = context.data.$mouseDownOn;

                                context.data.$mouseDownOn = $( [] );
                                if ( $result.get( 0 ) !== $other.get( 0 ) ) {
                                    return;
                                }
                                highlight( context, $result, true );
                                if ( typeof context.config.result.select === 'function' ) {
                                    context.config.result.select.call( $result, context.data.$textbox, 'mouse' );
                                }
                                // Don't interfere with special clicks (e.g. to open in new tab)
                                if ( !( e.which !== 1 || e.altKey || e.ctrlKey || e.shiftKey || e.metaKey ) ) {
                                    // This will hide the link we're just clicking on, which causes problems
                                    // when done synchronously in at least Firefox 3.6 (T64858).
                                    setTimeout( function () {
                                        hide( context );
                                    } );
                                }
                                // Always bring focus to the textbox, as that's probably where the user expects it
                                // if they were just typing.
                                context.data.$textbox.trigger( 'focus' );
                            } )
                    )
                    .append(
                        $( '<div>' ).addClass( 'suggestions-special' )
                            // Can't use click() because the container div is hidden when the
                            // textbox loses focus. Instead, listen for a mousedown followed
                            // by a mouseup on the same div.
                            .on( 'mousedown', function ( e ) {
                                context.data.$mouseDownOn = $( e.target ).closest( '.suggestions-special' );
                            } )
                            .on( 'mouseup', function ( e ) {
                                var $special = $( e.target ).closest( '.suggestions-special' ),
                                    $other = context.data.$mouseDownOn;

                                context.data.$mouseDownOn = $( [] );
                                if ( $special.get( 0 ) !== $other.get( 0 ) ) {
                                    return;
                                }
                                if ( typeof context.config.special.select === 'function' ) {
                                    context.config.special.select.call( $special, context.data.$textbox, 'mouse' );
                                }
                                // Don't interfere with special clicks (e.g. to open in new tab)
                                if ( !( e.which !== 1 || e.altKey || e.ctrlKey || e.shiftKey || e.metaKey ) ) {
                                    // This will hide the link we're just clicking on, which causes problems
                                    // when done synchronously in at least Firefox 3.6 (T64858).
                                    setTimeout( function () {
                                        hide( context );
                                    } );
                                }
                                // Always bring focus to the textbox, as that's probably where the user expects it
                                // if they were just typing.
                                context.data.$textbox.trigger( 'focus' );
                            } )
                            .on( 'mousemove', function ( e ) {
                                context.data.selectedWithMouse = true;
                                highlight(
                                    context, $( e.target ).closest( '.suggestions-special' ), false
                                );
                            } )
                    )
                    .appendTo( document.body );

                $( this )
                    // Stop browser autocomplete from interfering
                    .attr( 'autocomplete', 'off' )
                    .on( 'keydown', function ( e ) {
                        // Store key pressed to handle later
                        context.data.keypressed = e.which;
                        context.data.keypressedCount = 0;
                    } )
                    .on( 'keypress', function ( e ) {
                        context.data.keypressedCount++;
                        keypress( e, context, context.data.keypressed );
                    } )
                    .on( 'keyup', function ( e ) {
                        // The keypress event is fired when a key is pressed down and that key normally
                        // produces a character value. We also want to handle some keys that don't
                        // produce a character value so we also attach to the keydown/keyup events.
                        // List of codes sourced from
                        // https://developer.mozilla.org/en-US/docs/Web/API/KeyboardEvent/keyCode
                        var allowed = [
                            40, // up arrow
                            38, // down arrow
                            27, // escape
                            13, // enter
                            46, // delete
                            8 //   backspace
                        ];
                        if ( context.data.keypressedCount === 0 &&
                            e.which === context.data.keypressed &&
                            allowed.indexOf( e.which ) !== -1
                        ) {
                            keypress( e, context, context.data.keypressed );
                        }
                    } )
                    .on( 'blur', function () {
                        // When losing focus because of a mousedown
                        // on a suggestion, don't hide the suggestions
                        if ( context.data.$mouseDownOn.length > 0 ) {
                            return;
                        }
                        hide( context );
                        cancel( context );
                    } );
                // Load suggestions if the value is changed because there are already
                // typed characters before the JavaScript is loaded.
                if ( $( this ).is( ':focus' ) && this.value !== this.defaultValue ) {
                    update( context, false );
                }
            }

            // Store the context for next time
            $( this ).data( 'suggestions-context', context );
        } );
        return this;
    };

    /**
     * @class jQuery
     * @mixes jQuery.plugin.suggestions
     */

}() );