Events: Create options

Event and helper classes to provide option_callback's via events., _(*1)

In your DCA, define the options_callback with the factory class CreateOptionsEventCallbackFactory., _(*2)

use ContaoCommunityAlliance\Contao\Events\CreateOptions\CreateOptionsEventCallbackFactory;

$GLOBALS['TL_DCA']['tl_foo']['fields']['some_select'] = array(
    'inputType' => 'select',
    ...
    'options_callback' => CreateOptionsEventCallbackFactory::createCallback('tl_foo.some_select.create-options'),
);

Now you can fill the options with an event listener, listening on the event named tl_foo.some_select.create-options., _(*3)

$GLOBALS['TL_EVENTS']['tl_foo.some_select.create-options'][] = function($event) {
    $options = $event->getOptions();

    $options['value1'] = 'label 1';
    $options['value2'] = 'label 2';
    $options['value3'] = 'label 3';
};

Manipulate the options with a second event listener is pretty easy., _(*4)

$GLOBALS['TL_EVENTS']['tl_foo.some_select.create-options'][] = array(
    function($event) {
        $options = $event->getOptions();

        // remove a default value
        unset($options['value2']);

        // add a new value
        $options['value4'] = 'label 4';
    },
    -10 // we need a lower priority here, to make sure this listener is triggered after the default listener
);

See the event dispatcher documentation for more examples how to listen on an event., _(*5)

Custom event

By default, an event of type ContaoCommunityAlliance\Contao\Events\CreateOptions\CreateOptionsEvent is used. If you want your own event type, you can pass the class or a factory method as second parameter to CreateOptionsEventCallbackFactory::createCallback()., _(*6)

First you need to write your own create-options event class., _(*7)

class MyCreateOptionsEvent extends \ContaoCommunityAlliance\Contao\Events\CreateOptions\CreateOptionsEvent
{
    protected $additionalData;

    function __construct($additionalData, \DataContainer $dataContainer, \ArrayObject $options = null)
    {
        parent::__construct($dataContainer, $options);
        $this->additionalData = $additionalData;
    }

    public function getAdditionalData()
    {
        return $this->additionalData;
    }
}

Then you need to add your factory to CreateOptionsEventCallbackFactory::createCallback()., _(*8)

use ContaoCommunityAlliance\Contao\Events\CreateOptions\CreateOptionsEventCallbackFactory;

$GLOBALS['TL_DCA']['tl_foo']['fields']['some_select'] = array(
    'inputType' => 'select',
    ...
    'options_callback' => CreateOptionsEventCallbackFactory::createCallback(
        'tl_foo.some_select.create-options',
        function($dataContainer) {
            return new \MyCreateOptionsEvent(array('some' => 'value'), $dc);
        }
    ),
);