jQueryUI autocomplete not working with dialog and zIndex

Question

I ran into an interesting issue with jQueryUI autocomplete in a dialog box.

My dialog HTML looks like this:

Answer 1

The 'appendTo' option does not always work.

Most egregiously, it will not display past the height of the dialog, but also, if you are using a 3rd party utility (e.g. DataTables editor) you do not always have control over when a dialog, an input, etc. are being created, when they are attached to the DOM, what IDs they have, etc.

This seems to always work:

$(selector).autocomplete({
    open: function(event, ui){
        var dialog = $(this).closest('.ui-dialog');
        if(dialog.length > 0){
            $('.ui-autocomplete.ui-front').zIndex(dialog.zIndex()+1);
        }
    }
});