--- /dev/null
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\CssSelector\XPath\Extension;
+
+use Symfony\Component\CssSelector\Node;
+use Symfony\Component\CssSelector\XPath\Translator;
+use Symfony\Component\CssSelector\XPath\XPathExpr;
+
+/**
+ * XPath expression translator node extension.
+ *
+ * This component is a port of the Python cssselect library,
+ * which is copyright Ian Bicking, @see https://github.com/SimonSapin/cssselect.
+ *
+ * @author Jean-François Simon <jeanfrancois.simon@sensiolabs.com>
+ *
+ * @internal
+ */
+class NodeExtension extends AbstractExtension
+{
+ const ELEMENT_NAME_IN_LOWER_CASE = 1;
+ const ATTRIBUTE_NAME_IN_LOWER_CASE = 2;
+ const ATTRIBUTE_VALUE_IN_LOWER_CASE = 4;
+
+ /**
+ * @var int
+ */
+ private $flags;
+
+ /**
+ * Constructor.
+ *
+ * @param int $flags
+ */
+ public function __construct($flags = 0)
+ {
+ $this->flags = $flags;
+ }
+
+ /**
+ * @param int $flag
+ * @param bool $on
+ *
+ * @return $this
+ */
+ public function setFlag($flag, $on)
+ {
+ if ($on && !$this->hasFlag($flag)) {
+ $this->flags += $flag;
+ }
+
+ if (!$on && $this->hasFlag($flag)) {
+ $this->flags -= $flag;
+ }
+
+ return $this;
+ }
+
+ /**
+ * @param int $flag
+ *
+ * @return bool
+ */
+ public function hasFlag($flag)
+ {
+ return $this->flags & $flag;
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function getNodeTranslators()
+ {
+ return array(
+ 'Selector' => array($this, 'translateSelector'),
+ 'CombinedSelector' => array($this, 'translateCombinedSelector'),
+ 'Negation' => array($this, 'translateNegation'),
+ 'Function' => array($this, 'translateFunction'),
+ 'Pseudo' => array($this, 'translatePseudo'),
+ 'Attribute' => array($this, 'translateAttribute'),
+ 'Class' => array($this, 'translateClass'),
+ 'Hash' => array($this, 'translateHash'),
+ 'Element' => array($this, 'translateElement'),
+ );
+ }
+
+ /**
+ * @param Node\SelectorNode $node
+ * @param Translator $translator
+ *
+ * @return XPathExpr
+ */
+ public function translateSelector(Node\SelectorNode $node, Translator $translator)
+ {
+ return $translator->nodeToXPath($node->getTree());
+ }
+
+ /**
+ * @param Node\CombinedSelectorNode $node
+ * @param Translator $translator
+ *
+ * @return XPathExpr
+ */
+ public function translateCombinedSelector(Node\CombinedSelectorNode $node, Translator $translator)
+ {
+ return $translator->addCombination($node->getCombinator(), $node->getSelector(), $node->getSubSelector());
+ }
+
+ /**
+ * @param Node\NegationNode $node
+ * @param Translator $translator
+ *
+ * @return XPathExpr
+ */
+ public function translateNegation(Node\NegationNode $node, Translator $translator)
+ {
+ $xpath = $translator->nodeToXPath($node->getSelector());
+ $subXpath = $translator->nodeToXPath($node->getSubSelector());
+ $subXpath->addNameTest();
+
+ if ($subXpath->getCondition()) {
+ return $xpath->addCondition(sprintf('not(%s)', $subXpath->getCondition()));
+ }
+
+ return $xpath->addCondition('0');
+ }
+
+ /**
+ * @param Node\FunctionNode $node
+ * @param Translator $translator
+ *
+ * @return XPathExpr
+ */
+ public function translateFunction(Node\FunctionNode $node, Translator $translator)
+ {
+ $xpath = $translator->nodeToXPath($node->getSelector());
+
+ return $translator->addFunction($xpath, $node);
+ }
+
+ /**
+ * @param Node\PseudoNode $node
+ * @param Translator $translator
+ *
+ * @return XPathExpr
+ */
+ public function translatePseudo(Node\PseudoNode $node, Translator $translator)
+ {
+ $xpath = $translator->nodeToXPath($node->getSelector());
+
+ return $translator->addPseudoClass($xpath, $node->getIdentifier());
+ }
+
+ /**
+ * @param Node\AttributeNode $node
+ * @param Translator $translator
+ *
+ * @return XPathExpr
+ */
+ public function translateAttribute(Node\AttributeNode $node, Translator $translator)
+ {
+ $name = $node->getAttribute();
+ $safe = $this->isSafeName($name);
+
+ if ($this->hasFlag(self::ATTRIBUTE_NAME_IN_LOWER_CASE)) {
+ $name = strtolower($name);
+ }
+
+ if ($node->getNamespace()) {
+ $name = sprintf('%s:%s', $node->getNamespace(), $name);
+ $safe = $safe && $this->isSafeName($node->getNamespace());
+ }
+
+ $attribute = $safe ? '@'.$name : sprintf('attribute::*[name() = %s]', Translator::getXpathLiteral($name));
+ $value = $node->getValue();
+ $xpath = $translator->nodeToXPath($node->getSelector());
+
+ if ($this->hasFlag(self::ATTRIBUTE_VALUE_IN_LOWER_CASE)) {
+ $value = strtolower($value);
+ }
+
+ return $translator->addAttributeMatching($xpath, $node->getOperator(), $attribute, $value);
+ }
+
+ /**
+ * @param Node\ClassNode $node
+ * @param Translator $translator
+ *
+ * @return XPathExpr
+ */
+ public function translateClass(Node\ClassNode $node, Translator $translator)
+ {
+ $xpath = $translator->nodeToXPath($node->getSelector());
+
+ return $translator->addAttributeMatching($xpath, '~=', '@class', $node->getName());
+ }
+
+ /**
+ * @param Node\HashNode $node
+ * @param Translator $translator
+ *
+ * @return XPathExpr
+ */
+ public function translateHash(Node\HashNode $node, Translator $translator)
+ {
+ $xpath = $translator->nodeToXPath($node->getSelector());
+
+ return $translator->addAttributeMatching($xpath, '=', '@id', $node->getId());
+ }
+
+ /**
+ * @param Node\ElementNode $node
+ *
+ * @return XPathExpr
+ */
+ public function translateElement(Node\ElementNode $node)
+ {
+ $element = $node->getElement();
+
+ if ($this->hasFlag(self::ELEMENT_NAME_IN_LOWER_CASE)) {
+ $element = strtolower($element);
+ }
+
+ if ($element) {
+ $safe = $this->isSafeName($element);
+ } else {
+ $element = '*';
+ $safe = true;
+ }
+
+ if ($node->getNamespace()) {
+ $element = sprintf('%s:%s', $node->getNamespace(), $element);
+ $safe = $safe && $this->isSafeName($node->getNamespace());
+ }
+
+ $xpath = new XPathExpr('', $element);
+
+ if (!$safe) {
+ $xpath->addNameTest();
+ }
+
+ return $xpath;
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function getName()
+ {
+ return 'node';
+ }
+
+ /**
+ * Tests if given name is safe.
+ *
+ * @param string $name
+ *
+ * @return bool
+ */
+ private function isSafeName($name)
+ {
+ return 0 < preg_match('~^[a-zA-Z_][a-zA-Z0-9_.-]*$~', $name);
+ }
+}