Hello, For example i have a 'country' and 'city' table in db. CountryID is referenced in city table.
How can i generate a dropdown list so that i have something like this:

Australia
- Sydney
- Melbourne
New Zealand
- Auckland
- Wellington

My code is something as below

City.php Model

function getActiveCities(){
$countries = Dataobject::get('Country', 'Active=1');
$allcities = new DataObjectSet();
foreach($countries as $country){
$cities = DataObject::get('DealCity', 'Active=1 AND CountryID='.$country->ID)->map('ID', 'Title');
$allcities->push($cities);
}
return $allcities;
}

Page Controller in CMS
...
$cities = City::getActiveCities();
$fields->addFieldToTab('Root.Content.Main', new DropdownField('City','Select city', $cities));
....

This does give the output of cities in the dropdown but not the expected output that i desire as above!

Can someone please eleborate on this or is there a better way of doing nested dropdowns in SS??

cheers
Nadz

Dang, I managed to find the solution myself and it took me half an hour to figure out how to do this.

Here is the code below that shall do the magic.

function getActiveCities(){
$countries = Dataobject::get('Country', 'Active=1');
$cityarray = array();
foreach($countries as $country){
$cityarray[$country->Title] = array();
$cities = DataObject::get('City', 'Active=1 AND CountryID='.$country->ID);
foreach($cities as $city){
$cityarray[$country->Title][$city->ID]=$city->Title;
}
}
return $cityarray;
}

And the controller code:

$fields->addFieldToTab('Root.Content.Main', new GroupedDropdownField('City','Select city', City::getActiveCities()));

Hope this helps someone...

cheers
Nadz