Create OPTGROUP in CakePHP

// Define arrays filled with test data; would normally come from your database
    $cars = array('Ferrari', 'Bugatti', 'Porsche');
    $babes = array('Megan Fox', 'Alyssa Milano', 'Doutzen Kroes');
 
    // Create an empty array to be filled with options
    $options = array();
 
    // Create the initial option
    $options[] = JHTML :: _('select.option', '', '- What do you like most -');
 
    // Open our 'Cars' optgroup
    $options[] = JHTML::_('select.optgroup', 'Cars');
 
    // Loop through the 'Cars' data
    foreach($cars as $key => $text) {
     // Create each option tag within this optgroup
     $options[] = JHTML::_('select.option', $key, $text);
    }
 
    // Use the hack below to close the optgroup
    $options[] = JHTML::_('select.option', '');
 
    // Now open our 'Babes' optgroup
    $options[] = JHTML::_('select.optgroup', 'Babes');
 
    // Loop through the 'Babes' data this time
    foreach($babes as $key => $text) {
     // Create each option tag within this optgroup
     $options[] = JHTML::_('select.option', $key, $text);
    }
 
    // Use the hack below to close this last optgroup
    $options[] = JHTML::_('select.option', '');
 
    // Generate the select element with our parameters
    $select = JHTML::_(
     'select.genericlist', // Because we are creating a 'select' element
     $options,             // The options we created above
     'select_name',        // The name your select element should have in your HTML
     'size="1" ',          // Extra parameters to add to your element
     'value',              // The name of the object variable for the option value
     'text',               // The name of the object variable for the option text
     'selected_key',       // The key that is selected (accepts an array or a string)
     false                 // Translate the option results?
    );
 
echo $select;
    ?>