EntityCompatibility::setCallback

public function setCallback(array $callback)
{

	if (($sql = call_user_func_array($callback, array())) && strval(trim($sql)) != '')
	{
		$this->query->registerRuntimeField('',
									 new EntityExpressionField(
										 '__CALLBACK',
										 '(CASE WHEN ('.$sql.') THEN 1 ELSE 0 END)'
									 )
		);
		$this->query->addFilter('=__CALLBACK', 1);
	}
}