Alex had created some extensions to ComboBox that handled pre-population of Country and State information. They solved his problem and hopefully worked for others as well, but i just had the occasion to start using them and ran into some issues.
The first issue is that they extend ComboBox. When you need to set the value of a ComobBox you have to go through the grief of iterating over a loop. Luckily, I've already addressed the needed additions to support a ComboBox selectedValue property. So getting this up and running, at least initially, was as easy as changing ComboBox to eComboBox (you don't have to explicitely import the class if you put the definition in the same package).
The second issue is that needed states entry varies with the country. The US has its states and territories, as does Canada and probably some other countries too (If you aren't a mostly English speaking country on North America do you even exist? - just joking) so if the country input is open ended you might find yourself wanting comboboxes as well as textinputs. I originally had gone through the annoying process of maintaining two discrete comboboxes and a textinput and logic to control the visible and includeInLayout properties; that gets old quickly. Instead, I just wanted a single entry for the State information with a common property for setting and getting the selected value.
To make my life easier, I decided to just extend what Alex had created by just consolidating the XML dataProviders. For some reason, he had already included a country property so it was easy enough to group them together so as to be able to filter them later: