dynamic defaut value for filter using service

[Yannick Alsberge]

Hi, 

i'm trying to define a default value for a list filter dynamically. By dynamically I mean not a value I can add directly in the admin using the datagridValues but using a value determined @runtime. 

I've setup a event listener based on the sonata.admin.event.configure.list... In it I've tried to add a filter but even that doesn't work. 

Here's how I create and add the filter...

$fieldDescription = $event->getAdmin()->getModelManager()->getNewFieldDescriptionInstance(
    $event->getAdmin()->getClass(),
    'contentNode.sourceDomain',
    array(
        'field_type' => 'entity',
        'field_options' => array(
            'choice_label' => 'displayName',
        )
    )
);

$event->getAdmin()->addFilterFieldDescription('newFilter', $fieldDescription);

Is there a way to add a filter (and on top of that specifying a default value for it) within this event listener?

Thanks,

Yannick