lainchan/inc/lib/Twig/NodeVisitor/SafeAnalysis.php
2012-04-09 20:52:26 +10:00

108 lines
3.3 KiB
PHP

<?php
class Twig_NodeVisitor_SafeAnalysis implements Twig_NodeVisitorInterface
{
protected $data = array();
public function getSafe(Twig_NodeInterface $node)
{
$hash = spl_object_hash($node);
if (isset($this->data[$hash])) {
foreach($this->data[$hash] as $bucket) {
if ($bucket['key'] === $node) {
return $bucket['value'];
}
}
}
return null;
}
protected function setSafe(Twig_NodeInterface $node, array $safe)
{
$hash = spl_object_hash($node);
if (isset($this->data[$hash])) {
foreach($this->data[$hash] as &$bucket) {
if ($bucket['key'] === $node) {
$bucket['value'] = $safe;
return;
}
}
}
$this->data[$hash][] = array(
'key' => $node,
'value' => $safe,
);
}
public function enterNode(Twig_NodeInterface $node, Twig_Environment $env)
{
return $node;
}
public function leaveNode(Twig_NodeInterface $node, Twig_Environment $env)
{
if ($node instanceof Twig_Node_Expression_Constant) {
// constants are marked safe for all
$this->setSafe($node, array('all'));
} elseif ($node instanceof Twig_Node_Expression_BlockReference) {
// blocks are safe by definition
$this->setSafe($node, array('all'));
} elseif ($node instanceof Twig_Node_Expression_Parent) {
// parent block is safe by definition
$this->setSafe($node, array('all'));
} elseif ($node instanceof Twig_Node_Expression_Conditional) {
// intersect safeness of both operands
$safe = $this->intersectSafe($this->getSafe($node->getNode('expr2')), $this->getSafe($node->getNode('expr3')));
$this->setSafe($node, $safe);
} elseif ($node instanceof Twig_Node_Expression_Filter) {
// filter expression is safe when the filter is safe
$name = $node->getNode('filter')->getAttribute('value');
$args = $node->getNode('arguments');
if (false !== $filter = $env->getFilter($name)) {
$this->setSafe($node, $filter->getSafe($args));
} else {
$this->setSafe($node, array());
}
} elseif ($node instanceof Twig_Node_Expression_Function) {
// function expression is safe when the function is safe
$name = $node->getAttribute('name');
$args = $node->getNode('arguments');
$function = $env->getFunction($name);
if (false !== $function) {
$this->setSafe($node, $function->getSafe($args));
} else {
$this->setSafe($node, array());
}
} else {
$this->setSafe($node, array());
}
return $node;
}
protected function intersectSafe(array $a = null, array $b = null)
{
if (null === $a || null === $b) {
return array();
}
if (in_array('all', $a)) {
return $b;
}
if (in_array('all', $b)) {
return $a;
}
return array_intersect($a, $b);
}
/**
* {@inheritdoc}
*/
public function getPriority()
{
return 0;
}
}