public function valueNode() { // date value (either a DateTime object, or null) $valueNode = parent::valueNode(); // format('Y-m-d') method call on date object $args = new \Twig_Node_Expression_Array([], $this->lineno); $args->addElement(new \Twig_Node_Expression_Constant('j M, Y', $this->lineno)); $formatNode = new \Twig_Node_Expression_MethodCall($valueNode, 'format', $args, $this->lineno); // conditional to check for a null value $conditionalNode = new \Twig_Node_Expression_Conditional($valueNode, $formatNode, $valueNode, $this->lineno); return $conditionalNode; }