I was trying treegroup connector.
My category field contains values with apostrophes, and I noticed that the treegroup connector renders malformed xml in such a case, and on client side the browser cannot load the data.
<?xml version='1.0' encoding='utf-8' ?><tree id='0'><item id='Corte d'Appello di Ancona__{group_param}' text='Corte d'Appello di Ancona'
...
The text attribute is correctly formatted, while id is not
I am not so confident with dhtmlx code, so I do not know how to correct it