Expanding on @Jarry's suggestion, I would update your code to determine what optgroup the option belongs to. From there, you can use similar code as found on the jQueryUI website:
(function($) {
$.widget("ui.combobox", {
_create: function() {
var input, self = this,
select = this.element.hide(),
selected = select.children(":selected"),
value = selected.val() ? selected.text() : "",
wrapper = this.wrapper = $("<span>").addClass("ui-combobox").insertAfter(select);
input = $("<input>").appendTo(wrapper).val(value).addClass("ui-state-default ui-combobox-input").autocomplete({
delay: 0,
minLength: 0,
source: function(request, response) {
var matcher = new RegExp($.ui.autocomplete.escapeRegex(request.term), "i");
response(select.find("option").map(function() {
var text = $(this).text();
if (this.value && (!request.term || matcher.test(text))) return {
label: text.replace(
new RegExp("(?![^&;]+;)(?!<[^<>]*)(" + $.ui.autocomplete.escapeRegex(request.term) + ")(?![^<>]*>)(?![^&;]+;)", "gi"), "<strong>$1</strong>"),
value: text,
option: this,
category: $(this).closest("optgroup").attr("label")
};
//MK
$('#test').attr('style', 'display: none;');
}).get());
},
select: function(event, ui) {
ui.item.option.selected = true;
self._trigger("selected", event, {
item: ui.item.option
});
},
change: function(event, ui) {
if (!ui.item) {
var matcher = new RegExp("^" + $.ui.autocomplete.escapeRegex($(this).val()) + "$", "i"),
valid = false;
select.children("option").each(function() {
if ($(this).text().match(matcher)) {
this.selected = valid = true;
return false;
}
});
if (!valid) {
$('#test').attr('style', 'display: block;');
// remove invalid value, as it didn't match anything
//$( this ).val( "" );
//select.val( "" );
//input.data( "autocomplete" ).term = "";
//return false;
}
}
}
}).addClass("ui-widget ui-widget-content ui-corner-left");
input.data("autocomplete")._renderItem = function(ul, item) {
return $("<li></li>").data("item.autocomplete", item).append("<a>" + item.label + "</a>").appendTo(ul);
};
input.data("autocomplete")._renderMenu = function(ul, items) {
var self = this,
currentCategory = "";
$.each(items, function(index, item) {
if (item.category != currentCategory) {
if (item.category) {
ul.append("<li class='ui-autocomplete-category'>" + item.category + "</li>");
}
currentCategory = item.category;
}
self._renderItem(ul, item);
});
};
$("<a>").attr("tabIndex", -1).attr("title", "Show All Items").appendTo(wrapper).button({
icons: {
primary: "ui-icon-triangle-1-s"
},
text: false
}).removeClass("ui-corner-all").addClass("ui-corner-right ui-combobox-toggle").click(function() {
// close if already visible
if (input.autocomplete("widget").is(":visible")) {
input.autocomplete("close");
return;
}
// work around a bug (likely same cause as #5265)
$(this).blur();
// pass empty string as value to search for, displaying all results
input.autocomplete("search", "");
input.focus();
});
},
destroy: function() {
this.wrapper.remove();
this.element.show();
$.Widget.prototype.destroy.call(this);
}
});
})(jQuery);
$(function() {
$("#combobox").combobox();
$("#toggle").click(function() {
$("#combobox").toggle();
});
});
Example: http://jsfiddle.net/gB32r/
