Chris@0: <?php
Chris@0: 
Chris@0: /*
Chris@0:  * This file is part of the Symfony package.
Chris@0:  *
Chris@0:  * (c) Fabien Potencier <fabien@symfony.com>
Chris@0:  *
Chris@0:  * For the full copyright and license information, please view the LICENSE
Chris@0:  * file that was distributed with this source code.
Chris@0:  */
Chris@0: 
Chris@0: namespace Symfony\Component\CssSelector\XPath\Extension;
Chris@0: 
Chris@0: use Symfony\Component\CssSelector\Exception\ExpressionErrorException;
Chris@0: use Symfony\Component\CssSelector\Exception\SyntaxErrorException;
Chris@0: use Symfony\Component\CssSelector\Node\FunctionNode;
Chris@0: use Symfony\Component\CssSelector\Parser\Parser;
Chris@0: use Symfony\Component\CssSelector\XPath\Translator;
Chris@0: use Symfony\Component\CssSelector\XPath\XPathExpr;
Chris@0: 
Chris@0: /**
Chris@0:  * XPath expression translator function extension.
Chris@0:  *
Chris@0:  * This component is a port of the Python cssselect library,
Chris@0:  * which is copyright Ian Bicking, @see https://github.com/SimonSapin/cssselect.
Chris@0:  *
Chris@0:  * @author Jean-François Simon <jeanfrancois.simon@sensiolabs.com>
Chris@0:  *
Chris@0:  * @internal
Chris@0:  */
Chris@0: class FunctionExtension extends AbstractExtension
Chris@0: {
Chris@0:     /**
Chris@0:      * {@inheritdoc}
Chris@0:      */
Chris@0:     public function getFunctionTranslators()
Chris@0:     {
Chris@17:         return [
Chris@17:             'nth-child' => [$this, 'translateNthChild'],
Chris@17:             'nth-last-child' => [$this, 'translateNthLastChild'],
Chris@17:             'nth-of-type' => [$this, 'translateNthOfType'],
Chris@17:             'nth-last-of-type' => [$this, 'translateNthLastOfType'],
Chris@17:             'contains' => [$this, 'translateContains'],
Chris@17:             'lang' => [$this, 'translateLang'],
Chris@17:         ];
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * @param XPathExpr    $xpath
Chris@0:      * @param FunctionNode $function
Chris@0:      * @param bool         $last
Chris@0:      * @param bool         $addNameTest
Chris@0:      *
Chris@0:      * @return XPathExpr
Chris@0:      *
Chris@0:      * @throws ExpressionErrorException
Chris@0:      */
Chris@0:     public function translateNthChild(XPathExpr $xpath, FunctionNode $function, $last = false, $addNameTest = true)
Chris@0:     {
Chris@0:         try {
Chris@0:             list($a, $b) = Parser::parseSeries($function->getArguments());
Chris@0:         } catch (SyntaxErrorException $e) {
Chris@0:             throw new ExpressionErrorException(sprintf('Invalid series: %s', implode(', ', $function->getArguments())), 0, $e);
Chris@0:         }
Chris@0: 
Chris@0:         $xpath->addStarPrefix();
Chris@0:         if ($addNameTest) {
Chris@0:             $xpath->addNameTest();
Chris@0:         }
Chris@0: 
Chris@0:         if (0 === $a) {
Chris@0:             return $xpath->addCondition('position() = '.($last ? 'last() - '.($b - 1) : $b));
Chris@0:         }
Chris@0: 
Chris@0:         if ($a < 0) {
Chris@0:             if ($b < 1) {
Chris@0:                 return $xpath->addCondition('false()');
Chris@0:             }
Chris@0: 
Chris@0:             $sign = '<=';
Chris@0:         } else {
Chris@0:             $sign = '>=';
Chris@0:         }
Chris@0: 
Chris@0:         $expr = 'position()';
Chris@0: 
Chris@0:         if ($last) {
Chris@0:             $expr = 'last() - '.$expr;
Chris@0:             --$b;
Chris@0:         }
Chris@0: 
Chris@0:         if (0 !== $b) {
Chris@0:             $expr .= ' - '.$b;
Chris@0:         }
Chris@0: 
Chris@17:         $conditions = [sprintf('%s %s 0', $expr, $sign)];
Chris@0: 
Chris@0:         if (1 !== $a && -1 !== $a) {
Chris@0:             $conditions[] = sprintf('(%s) mod %d = 0', $expr, $a);
Chris@0:         }
Chris@0: 
Chris@0:         return $xpath->addCondition(implode(' and ', $conditions));
Chris@0: 
Chris@0:         // todo: handle an+b, odd, even
Chris@0:         // an+b means every-a, plus b, e.g., 2n+1 means odd
Chris@0:         // 0n+b means b
Chris@0:         // n+0 means a=1, i.e., all elements
Chris@0:         // an means every a elements, i.e., 2n means even
Chris@0:         // -n means -1n
Chris@0:         // -1n+6 means elements 6 and previous
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * @return XPathExpr
Chris@0:      */
Chris@0:     public function translateNthLastChild(XPathExpr $xpath, FunctionNode $function)
Chris@0:     {
Chris@0:         return $this->translateNthChild($xpath, $function, true);
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * @return XPathExpr
Chris@0:      */
Chris@0:     public function translateNthOfType(XPathExpr $xpath, FunctionNode $function)
Chris@0:     {
Chris@0:         return $this->translateNthChild($xpath, $function, false, false);
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * @return XPathExpr
Chris@0:      *
Chris@0:      * @throws ExpressionErrorException
Chris@0:      */
Chris@0:     public function translateNthLastOfType(XPathExpr $xpath, FunctionNode $function)
Chris@0:     {
Chris@0:         if ('*' === $xpath->getElement()) {
Chris@0:             throw new ExpressionErrorException('"*:nth-of-type()" is not implemented.');
Chris@0:         }
Chris@0: 
Chris@0:         return $this->translateNthChild($xpath, $function, true, false);
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * @return XPathExpr
Chris@0:      *
Chris@0:      * @throws ExpressionErrorException
Chris@0:      */
Chris@0:     public function translateContains(XPathExpr $xpath, FunctionNode $function)
Chris@0:     {
Chris@0:         $arguments = $function->getArguments();
Chris@0:         foreach ($arguments as $token) {
Chris@0:             if (!($token->isString() || $token->isIdentifier())) {
Chris@17:                 throw new ExpressionErrorException('Expected a single string or identifier for :contains(), got '.implode(', ', $arguments));
Chris@0:             }
Chris@0:         }
Chris@0: 
Chris@0:         return $xpath->addCondition(sprintf(
Chris@0:             'contains(string(.), %s)',
Chris@0:             Translator::getXpathLiteral($arguments[0]->getValue())
Chris@0:         ));
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * @return XPathExpr
Chris@0:      *
Chris@0:      * @throws ExpressionErrorException
Chris@0:      */
Chris@0:     public function translateLang(XPathExpr $xpath, FunctionNode $function)
Chris@0:     {
Chris@0:         $arguments = $function->getArguments();
Chris@0:         foreach ($arguments as $token) {
Chris@0:             if (!($token->isString() || $token->isIdentifier())) {
Chris@17:                 throw new ExpressionErrorException('Expected a single string or identifier for :lang(), got '.implode(', ', $arguments));
Chris@0:             }
Chris@0:         }
Chris@0: 
Chris@0:         return $xpath->addCondition(sprintf(
Chris@0:             'lang(%s)',
Chris@0:             Translator::getXpathLiteral($arguments[0]->getValue())
Chris@0:         ));
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * {@inheritdoc}
Chris@0:      */
Chris@0:     public function getName()
Chris@0:     {
Chris@0:         return 'function';
Chris@0:     }
Chris@0: }