wikimedia/wikimedia-fundraising-dash

define( [
    'knockout',
    'jquery',
    'c3',
    'select2' // source this file to create the $( 'foo' ).select2 function
], function ( ko, $, c3 /* , select2 */ ) {
    function destroyChart( element ) {
        var chart = ko.utils.domData.get( element, 'chart' );
        if ( chart ) {
            chart.destroy();
            ko.utils.domData.set( element, 'chart', undefined );
        }
    }

    ko.bindingHandlers.c3 = {
        init: function init( element, valueAccessor /* , allBindingsAccessor, viewModel, bindingContext */ ) {
            var chart, options = ko.unwrap( valueAccessor() );
            if ( !options ) {
                return;
            }
            options.bindto = element;
            chart = c3.generate( options );
            ko.utils.domNodeDisposal.addDisposeCallback( element, function () {
                destroyChart( element );
            } );
            ko.utils.domData.set( element, 'chart', chart );
        },
        update: function update( element, valueAccessor /* , allBindingsAccessor, viewModel, bindingContext */ ) {
            var chart = ko.utils.domData.get( element, 'chart' ),
                options = ko.unwrap( valueAccessor() );
            if ( !options ) {
                // Destroys existing chart if you pass a falsy value
                // TODO: also reset when options outside of data have changed.
                if ( chart ) {
                    destroyChart( element );
                }
                return;
            }
            if ( chart ) {
                chart.load( options.data );
                return;
            }
            options.bindto = element;
            chart = c3.generate( options );
            ko.utils.domNodeDisposal.addDisposeCallback( element, function () {
                destroyChart( element );
            } );
            ko.utils.domData.set( element, 'chart', chart );
        }
    };
    /**
     * From https://github.com/select2/select2/wiki/Knockout.js-Integration
     */
    ko.bindingHandlers.select2 = {
        init: function ( el, valueAccessor, allBindingsAccessor /* , viewModel */ ) {
            ko.utils.domNodeDisposal.addDisposeCallback( el, function () {
                $( el ).select2( 'destroy' );
            } );

            var allBindings = allBindingsAccessor(),
                select2 = ko.utils.unwrapObservable( allBindings.select2 );

            $( el ).select2( select2 );
        },
        update: function ( el, valueAccessor, allBindingsAccessor /* , viewModel */ ) {
            var allBindings = allBindingsAccessor(),
                converted,
                textAccessor;

            if ( 'value' in allBindings ) {
                if ( allBindings.select2.multiple && allBindings.value().constructor !== Array ) {
                    $( el ).select2( 'val', allBindings.value().split( ',' ) );
                } else {
                    $( el ).select2( 'val', allBindings.value() );
                }
            } else if ( 'selectedOptions' in allBindings ) {
                converted = [];
                textAccessor = function ( value ) {
                    return value;
                };
                if ( 'optionsText' in allBindings ) {
                    textAccessor = function ( value ) {
                        var items,
                            valueAccessor = function ( item ) {
                                return item;
                            };
                        if ( 'optionsValue' in allBindings ) {
                            valueAccessor = function ( item ) {
                                return item[ allBindings.optionsValue ];
                            };
                        }
                        items = ko.utils.unwrapObservable( allBindings.options ).filter( function ( e ) {
                            return valueAccessor( e ) === value;
                        } );
                        if ( items.length === 0 || items.length > 1 ) {
                            return 'UNKNOWN';
                        }
                        return items[ 0 ][ allBindings.optionsText ];
                    };
                }
                $.each( allBindings.selectedOptions(), function ( key, value ) {
                    converted.push( { id: value, text: textAccessor( value ) } );
                } );
                $( el ).select2( 'data', converted );
            }
        }
    };
    return true;
} );