wikimedia/mediawiki-extensions-UniversalLanguageSelector

View on GitHub
lib/jquery.uls/src/jquery.uls.core.js

Summary

Maintainability
C
7 hrs
Test Coverage
/**
 * Universal Language Selector
 * ULS core component.
 *
 * Copyright (C) 2012 Alolita Sharma, Amir Aharoni, Arun Ganesh, Brandon Harris,
 * Niklas Laxström, Pau Giner, Santhosh Thottingal, Siebrand Mazeland and other
 * contributors. See CREDITS for a list.
 *
 * UniversalLanguageSelector is dual licensed GPLv2 or later and MIT. You don't
 * have to do anything special to choose one license or the other and you don't
 * have to notify anyone which license you are using. You are free to use
 * UniversalLanguageSelector in commercial projects as long as the copyright
 * header is left intact. See files GPL-LICENSE and MIT-LICENSE for details.
 *
 * @file
 * @license GNU General Public Licence 2.0 or later
 * @license MIT License
 */

( function ( $ ) {
    'use strict';

    var template, ULS;

    // Region numbers in id attributes also appear in the langdb.
    template = '<div class="grid uls-menu"> \
            <div id="search" class="row uls-search"> \
                <div class="uls-search-wrapper"> \
                    <label class="uls-search-label" for="uls-languagefilter"></label>\
                    <div class="uls-search-input-wrapper">\
                        <span class="uls-languagefilter-clear"></span>\
                        <input type="text" class="uls-filterinput uls-filtersuggestion"\
                            disabled="true" autocomplete="off">\
                        <input type="text" class="uls-filterinput uls-languagefilter"\
                            maxlength="40"\
                            data-clear="uls-languagefilter-clear"\
                            data-suggestion="uls-filtersuggestion"\
                            placeholder="Search for a language" autocomplete="off">\
                    </div>\
                </div>\
            </div>\
            <div class="row uls-language-list"></div>\
            <div class="row" id="uls-settings-block"></div>\
        </div>';

    /**
     * ULS Public class definition
     *
     * @param {Element} element
     * @param {Object} options
     */
    ULS = function ( element, options ) {
        var code;
        this.$element = $( element );
        this.options = $.extend( {}, $.fn.uls.defaults, options );
        this.$menu = $( template );
        this.languages = this.options.languages;

        for ( code in this.languages ) {
            if ( $.uls.data.languages[ code ] === undefined ) {
                // Language is unknown to ULS.
                delete this.languages[ code ];
            }
        }

        this.left = this.options.left;
        this.top = this.options.top;
        this.shown = false;
        this.initialized = false;
        this.shouldRecreate = false;
        this.menuWidth = this.getMenuWidth();

        this.$languageFilter = this.$menu.find( '.uls-languagefilter' );
        this.$resultsView = this.$menu.find( '.uls-language-list' );

        this.render();
        this.listen();
        this.ready();
    };

    ULS.prototype = {
        constructor: ULS,

        /**
         * A "hook" that runs after the ULS constructor.
         * At this point it is not guaranteed that the ULS has its dimensions
         * and that the languages lists are initialized.
         *
         * To use it, pass a function as the onReady parameter
         * in the options when initializing ULS.
         */
        ready: function () {
            if ( this.options.onReady ) {
                this.options.onReady.call( this );
            }
        },

        /**
         * A "hook" that runs after the ULS panel becomes visible
         * by using the show method.
         *
         * To use it, pass a function as the onVisible parameter
         * in the options when initializing ULS.
         */
        visible: function () {
            if ( this.options.onVisible ) {
                this.options.onVisible.call( this );
            }
        },

        /**
         * Calculate the position of ULS
         * Returns an object with top and left properties.
         *
         * @return {Object}
         */
        position: function () {
            var pos,
                top = this.top,
                left = this.left;

            if ( this.options.onPosition ) {
                return this.options.onPosition.call( this );
            }

            // Default implementation (middle of the screen under the trigger)
            if ( top === undefined ) {
                pos = $.extend( {}, this.$element.offset(), {
                    height: this.$element[ 0 ].offsetHeight
                } );
                top = pos.top + pos.height;
            }

            if ( left === undefined ) {
                left = $( window ).width() / 2 - this.$menu.outerWidth() / 2;
            }

            return {
                top: top,
                left: left
            };
        },

        /**
         * Show the ULS window
         */
        show: function () {
            var widthClasses = {
                wide: 'uls-wide',
                medium: 'uls-medium',
                narrow: 'uls-narrow'
            };

            this.$menu.addClass( widthClasses[ this.menuWidth ] );

            if ( !this.initialized ) {
                $( document.body ).prepend( this.$menu );
                this.i18n();
                this.initialized = true;
            }

            this.$menu.css( this.position() );
            this.$menu.show();
            this.$menu.scrollIntoView();
            this.shown = true;

            if ( !this.isMobile() ) {
                this.$languageFilter.trigger( 'focus' );
            }

            this.visible();
        },

        i18n: function () {
            if ( $.i18n ) {
                this.$menu.find( '[data-i18n]' ).i18n();
                if ( this.getMenuWidth() === 'narrow' ) {
                    this.$languageFilter.prop( 'placeholder', $.i18n( 'uls-search-placeholder-short' ) );
                } else {
                    this.$languageFilter.prop( 'placeholder', $.i18n( 'uls-search-placeholder' ) );
                }
            }
        },

        /**
         * Hide the ULS window
         */
        hide: function () {
            this.$menu.hide();
            this.shown = false;

            this.$menu.removeClass( 'uls-wide uls-medium uls-narrow' );

            if ( this.shouldRecreate ) {
                this.recreateLanguageFilter();
            }

            if ( this.options.onCancel ) {
                this.options.onCancel.call( this );
            }
        },

        /**
         * Render the UI elements.
         * Does nothing by default. Can be used for customization.
         */
        render: function () {
            // Rendering stuff here
        },

        /**
         * Callback for results found context.
         */
        success: function () {
            this.$resultsView.show();
        },

        createLanguageFilter: function () {
            var lcd, languagesCount,
                columnsOptions = {
                    wide: 4,
                    medium: 2,
                    narrow: 1
                };

            languagesCount = Object.keys( this.options.languages ).length;
            lcd = this.$resultsView.lcd( {
                languages: this.languages,
                columns: columnsOptions[ this.menuWidth ],

                quickList: languagesCount > 12 ? this.options.quickList : [],
                clickhandler: this.select.bind( this ),
                showRegions: this.options.showRegions,
                languageDecorator: this.options.languageDecorator,
                noResultsTemplate: this.options.noResultsTemplate,
                itemsPerColumn: this.options.itemsPerColumn,
                groupByRegion: this.options.groupByRegion
            } ).data( 'lcd' );

            this.$languageFilter.languagefilter( {
                lcd: lcd,
                languages: this.languages,
                ulsPurpose: this.options.ulsPurpose,
                searchAPI: this.options.searchAPI,
                onSelect: this.select.bind( this )
            } );

            this.$languageFilter.on( 'noresults.uls', lcd.noResults.bind( lcd ) );
        },

        recreateLanguageFilter: function () {
            this.$resultsView.removeData( 'lcd' );
            this.$resultsView.empty();
            this.$languageFilter.removeData( 'languagefilter' );
            this.createLanguageFilter();

            this.shouldRecreate = false;
        },

        /**
         * Bind the UI elements with their event listeners
         */
        listen: function () {
            // Register all event listeners to the ULS here.
            this.$element.on( 'click', this.click.bind( this ) );

            // Don't do anything if pressing on empty space in the ULS
            this.$menu.on( 'click', function ( e ) {
                e.stopPropagation();
            } );

            // Handle key press events on the menu
            this.$menu.on( 'keydown', this.keypress.bind( this ) );

            this.createLanguageFilter();

            this.$languageFilter.on( 'resultsfound.uls', this.success.bind( this ) );

            $( document.body ).on( 'click', this.cancel.bind( this ) );
            $( window ).on( 'resize', $.fn.uls.debounce( this.resize.bind( this ), 250 ) );
        },

        resize: function () {
            var menuWidth = this.getMenuWidth();

            if ( this.menuWidth === menuWidth ) {
                return;
            }

            this.menuWidth = menuWidth;
            this.shouldRecreate = true;
            if ( !this.shown ) {
                this.recreateLanguageFilter();
            }
        },

        /**
         * On select handler for search results
         *
         * @param {string} langCode
         * @param {Object} event The jQuery click event
         */
        select: function ( langCode, event ) {
            this.hide();
            if ( this.options.onSelect ) {
                this.options.onSelect.call( this, langCode, event );
            }
        },

        /**
         * On cancel handler for the uls menu
         *
         * @param {Event} e
         */
        cancel: function ( e ) {
            if ( e && ( this.$element.is( e.target ) ||
                $.contains( this.$element[ 0 ], e.target ) ) ) {
                return;
            }

            this.hide();
        },

        keypress: function ( e ) {
            if ( !this.shown ) {
                return;
            }

            if ( e.keyCode === 27 ) { // escape
                this.cancel();
                this.$element.trigger( 'focus' );
                e.preventDefault();
                e.stopPropagation();
            }
        },

        click: function () {
            if ( this.shown ) {
                this.hide();
            } else {
                this.show();
            }
        },

        /**
         * Get the panel menu width parameter
         *
         * @return {string}
         */
        getMenuWidth: function () {
            var languagesCount,
                screenWidth = document.documentElement.clientWidth;

            if ( this.options.menuWidth ) {
                return this.options.menuWidth;
            }

            languagesCount = Object.keys( this.options.languages ).length;

            if ( screenWidth > 900 && languagesCount >= 48 ) {
                return 'wide';
            }

            if ( screenWidth > 500 && languagesCount >= 24 ) {
                return 'medium';
            }

            return 'narrow';
        },

        isMobile: function () {
            return navigator.userAgent.match( /(iPhone|iPod|iPad|Android|BlackBerry)/ );
        }
    };

    /* ULS PLUGIN DEFINITION
     * =========================== */

    $.fn.uls = function ( option ) {
        return this.each( function () {
            var $this = $( this ),
                data = $this.data( 'uls' ),
                options = typeof option === 'object' && option;

            if ( !data ) {
                $this.data( 'uls', ( data = new ULS( this, options ) ) );
            }

            if ( typeof option === 'string' ) {
                data[ option ]();
            }
        } );
    };

    $.fn.uls.defaults = {
        // DEPRECATED: CSS top position for the dialog
        top: undefined,
        // DEPRECATED: CSS left position for the dialog
        left: undefined,
        // Callback function when user selects a language
        onSelect: undefined,
        // Callback function when the dialog is closed without selecting a language
        onCancel: undefined,
        // Callback function when ULS has initialized
        onReady: undefined,
        // Callback function when ULS dialog is shown
        onVisible: undefined,
        // Callback function when ULS dialog is ready to be shown
        onPosition: undefined,
        // Languages to be used for ULS, default is all languages
        languages: $.uls.data.getAutonyms(),
        // The options are wide (4 columns), medium (2 columns), and narrow (1 column).
        // If not specified, it will be set automatically.
        menuWidth: undefined,
        // What is this ULS used for.
        // Should be set for distinguishing between different instances of ULS
        // in the same application.
        ulsPurpose: '',
        // Used by LCD
        quickList: [],
        // Used by LCD
        showRegions: undefined,
        // Used by LCD
        languageDecorator: undefined,
        // Used by LCD
        noResultsTemplate: undefined,
        // Used by LCD
        itemsPerColumn: undefined,
        // Used by LCD
        groupByRegion: undefined,
        // Used by LanguageFilter
        searchAPI: undefined
    };

    // Define a dummy i18n function, if jquery.i18n not integrated.
    if ( !$.fn.i18n ) {
        $.fn.i18n = function () {};
    }

    /**
     * Creates and returns a new debounced version of the passed function,
     * which will postpone its execution, until after wait milliseconds have elapsed
     * since the last time it was invoked.
     *
     * @param {Function} fn Function to be debounced.
     * @param {number} wait Wait interval in milliseconds.
     * @param {boolean} [immediate] Trigger the function on the leading edge of the wait interval,
     * instead of the trailing edge.
     * @return {Function} Debounced function.
     */
    $.fn.uls.debounce = function ( fn, wait, immediate ) {
        var timeout;

        return function () {
            var callNow, self = this,
                later = function () {
                    timeout = null;
                    if ( !immediate ) {
                        fn.apply( self, arguments );
                    }
                };

            callNow = immediate && !timeout;
            clearTimeout( timeout );
            timeout = setTimeout( later, wait || 100 );

            if ( callNow ) {
                fn.apply( self, arguments );
            }
        };
    };

    /*
     * Simple scrollIntoView plugin.
     * Scrolls the element to the viewport smoothly if it is not already.
     */
    $.fn.scrollIntoView = function () {
        return this.each( function () {
            var scrollPosition,
                $window = $( window ),
                windowHeight = $window.height(),
                windowTop = $window.scrollTop(),
                windowBottom = windowTop + windowHeight,
                $element = $( this ),
                panelHeight = $element.height(),
                panelTop = $element.offset().top,
                panelBottom = panelTop + panelHeight;

            if ( ( panelTop < windowTop ) || ( panelBottom > windowBottom ) ) {
                if ( windowTop > panelTop ) {
                    scrollPosition = panelTop;
                } else {
                    scrollPosition = panelBottom - windowHeight;
                }
                // eslint-disable-next-line no-jquery/no-global-selector
                $( 'html, body' ).stop().animate( {
                    scrollTop: scrollPosition
                }, 500 );
            }
        } );
    };

    $.fn.uls.Constructor = ULS;
}( jQuery ) );