wysihtml5 ko binding handler

/**
 * Correct version of a wysihtml5 binding for KnockoutJS that is safe for multiple inclusion on a single page
 */
ko.bindingHandlers.wysihtml5 = {
        init: function (element, valueAccessor, allBindingsAccessor, viewModel) {
            var control = $(element).wysihtml5({
                "events": {
                    "change" : function() {
                        var observable = valueAccessor();
                        observable(control.getValue());
                    }
                }
            }).data("wysihtml5").editor;
            

        },
        update: function (element, valueAccessor, allBindingsAccessor, viewModel) {
            var content = valueAccessor();
            
            if (content != undefined) {
                var control = $(element).data("wysihtml5").editor;
                control.setValue(content());
            }
        }
    };