--- /dev/null
+<?php
+
+/*
+ * This file is part of Twig.
+ *
+ * (c) Fabien Potencier
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+/**
+ * Checks if a variable is defined in the current context.
+ *
+ * <pre>
+ * {# defined works with variable names and variable attributes #}
+ * {% if foo is defined %}
+ * {# ... #}
+ * {% endif %}
+ * </pre>
+ *
+ * @author Fabien Potencier <fabien@symfony.com>
+ */
+class Twig_Node_Expression_Test_Defined extends Twig_Node_Expression_Test
+{
+ public function __construct(Twig_NodeInterface $node, $name, Twig_NodeInterface $arguments = null, $lineno)
+ {
+ if ($node instanceof Twig_Node_Expression_Name) {
+ $node->setAttribute('is_defined_test', true);
+ } elseif ($node instanceof Twig_Node_Expression_GetAttr) {
+ $node->setAttribute('is_defined_test', true);
+ $this->changeIgnoreStrictCheck($node);
+ } elseif ($node instanceof Twig_Node_Expression_BlockReference) {
+ $node->setAttribute('is_defined_test', true);
+ } elseif ($node instanceof Twig_Node_Expression_Function && 'constant' === $node->getAttribute('name')) {
+ $node->setAttribute('is_defined_test', true);
+ } elseif ($node instanceof Twig_Node_Expression_Constant || $node instanceof Twig_Node_Expression_Array) {
+ $node = new Twig_Node_Expression_Constant(true, $node->getTemplateLine());
+ } else {
+ throw new Twig_Error_Syntax('The "defined" test only works with simple variables.', $this->getTemplateLine());
+ }
+
+ parent::__construct($node, $name, $arguments, $lineno);
+ }
+
+ protected function changeIgnoreStrictCheck(Twig_Node_Expression_GetAttr $node)
+ {
+ $node->setAttribute('ignore_strict_check', true);
+
+ if ($node->getNode('node') instanceof Twig_Node_Expression_GetAttr) {
+ $this->changeIgnoreStrictCheck($node->getNode('node'));
+ }
+ }
+
+ public function compile(Twig_Compiler $compiler)
+ {
+ $compiler->subcompile($this->getNode('node'));
+ }
+}