for example country and city
when you open the add dialog
Initially before you select the country the city drop down contains all the cities of all the world and the first country is already selected by default
this problem is also present in the demo provided with the latest version
is there a way to fix this?
can the city be initially hidden in the add / edit dialogs until you first select a country?
For initial blank value in country dropdown, You can append ":;" before $str (values of dropdown)
http://pastebin.com/JEs3ccL5 (line 42)
"value"=>":;".$str,
For hiding column,
I've added afterShowForm event in above link example, which connects to setup_fields() function where you can hide / show dependent dropdowns.
http://pastebin.com/JEs3ccL5 (line 112, 158)