Dropdown list with dyanmic optgroup

Question

Hi there cakephp experts! I am looking for you help on a dyanmic dropdown list with dyanamic optgroup. Suppose I have two tables:

 countries:  id, country_na         


        

Answer 1

bind tableB to tableA in tableA model, do

$hasMany = array("tableB"=>array("className"=>"tableB","foreignKey"=>"aId"));

then use

find("all")

might need

$this->tableA->recursive->2

right before find

Answer 2

You can also use the Hash::combine function instead of a nested loop as suggested by @neilcrookes

$counties = Hash::combine($countries,'{n}.County.id','{n}.County.name','{n}.Country.name'); 

Answer 3

Cake's FormHelper::input method will render a select tag with optgroups if the options are correct, e.g.

echo  $form->input('county');

provided there is a variable available in the view called $counties which contains data in the following format:

$counties = array(
  'Country Name 1' => array(
    'county_1_id' => 'County 1 Name',
    'county_2_id' => 'County 2 Name',
    'county_3_id' => 'County 3 Name',
  ),
  'Country Name 2' => array(
    'county_4_id' => 'County 4 Name',
    'county_5_id' => 'County 5 Name',
    'county_6_id' => 'County 6 Name',
  ),
);

So, in your controller, do something like:

$this->set('counties', ClassRegistry::init('Country')->getCountiesByCountry());

and in your Country Model, do something like:

function getCountiesByCountry() {
  $countries = $this->find('all', array('contain' => array('County')));
  $return = array();
  foreach ($countries as $country) {
    foreach ($country['County'] as $county) {
      $return[$country['Country']['name']][$county['id']] = $county['name'];
    }
  }
  return $return;
}