[Summary view] [Print] [Text view]

   1  <?php
   2  
   3  /*
   4   * This file is part of the Symfony package.
   5   *
   6   * (c) Fabien Potencier <fabien@symfony.com>
   7   *
   8   * For the full copyright and license information, please view the LICENSE
   9   * file that was distributed with this source code.
  10   */
  11  
  12  namespace Symfony\Component\CssSelector\Parser;
  13  
  14  use Symfony\Component\CssSelector\Exception\SyntaxErrorException;
  15  use Symfony\Component\CssSelector\Node;
  16  use Symfony\Component\CssSelector\Parser\Tokenizer\Tokenizer;
  17  
  18  /**
  19   * CSS selector parser.
  20   *
  21   * This component is a port of the Python cssselect library,
  22   * which is copyright Ian Bicking, @see https://github.com/SimonSapin/cssselect.
  23   *
  24   * @author Jean-François Simon <jeanfrancois.simon@sensiolabs.com>
  25   *
  26   * @internal
  27   */
  28  class Parser implements ParserInterface
  29  {
  30      private $tokenizer;
  31  
  32      public function __construct(Tokenizer $tokenizer = null)
  33      {
  34          $this->tokenizer = $tokenizer ?? new Tokenizer();
  35      }
  36  
  37      /**
  38       * {@inheritdoc}
  39       */
  40      public function parse(string $source): array
  41      {
  42          $reader = new Reader($source);
  43          $stream = $this->tokenizer->tokenize($reader);
  44  
  45          return $this->parseSelectorList($stream);
  46      }
  47  
  48      /**
  49       * Parses the arguments for ":nth-child()" and friends.
  50       *
  51       * @param Token[] $tokens
  52       *
  53       * @throws SyntaxErrorException
  54       */
  55      public static function parseSeries(array $tokens): array
  56      {
  57          foreach ($tokens as $token) {
  58              if ($token->isString()) {
  59                  throw SyntaxErrorException::stringAsFunctionArgument();
  60              }
  61          }
  62  
  63          $joined = trim(implode('', array_map(function (Token $token) {
  64              return $token->getValue();
  65          }, $tokens)));
  66  
  67          $int = function ($string) {
  68              if (!is_numeric($string)) {
  69                  throw SyntaxErrorException::stringAsFunctionArgument();
  70              }
  71  
  72              return (int) $string;
  73          };
  74  
  75          switch (true) {
  76              case 'odd' === $joined:
  77                  return [2, 1];
  78              case 'even' === $joined:
  79                  return [2, 0];
  80              case 'n' === $joined:
  81                  return [1, 0];
  82              case !str_contains($joined, 'n'):
  83                  return [0, $int($joined)];
  84          }
  85  
  86          $split = explode('n', $joined);
  87          $first = $split[0] ?? null;
  88  
  89          return [
  90              $first ? ('-' === $first || '+' === $first ? $int($first.'1') : $int($first)) : 1,
  91              isset($split[1]) && $split[1] ? $int($split[1]) : 0,
  92          ];
  93      }
  94  
  95      private function parseSelectorList(TokenStream $stream): array
  96      {
  97          $stream->skipWhitespace();
  98          $selectors = [];
  99  
 100          while (true) {
 101              $selectors[] = $this->parserSelectorNode($stream);
 102  
 103              if ($stream->getPeek()->isDelimiter([','])) {
 104                  $stream->getNext();
 105                  $stream->skipWhitespace();
 106              } else {
 107                  break;
 108              }
 109          }
 110  
 111          return $selectors;
 112      }
 113  
 114      private function parserSelectorNode(TokenStream $stream): Node\SelectorNode
 115      {
 116          [$result, $pseudoElement] = $this->parseSimpleSelector($stream);
 117  
 118          while (true) {
 119              $stream->skipWhitespace();
 120              $peek = $stream->getPeek();
 121  
 122              if ($peek->isFileEnd() || $peek->isDelimiter([','])) {
 123                  break;
 124              }
 125  
 126              if (null !== $pseudoElement) {
 127                  throw SyntaxErrorException::pseudoElementFound($pseudoElement, 'not at the end of a selector');
 128              }
 129  
 130              if ($peek->isDelimiter(['+', '>', '~'])) {
 131                  $combinator = $stream->getNext()->getValue();
 132                  $stream->skipWhitespace();
 133              } else {
 134                  $combinator = ' ';
 135              }
 136  
 137              [$nextSelector, $pseudoElement] = $this->parseSimpleSelector($stream);
 138              $result = new Node\CombinedSelectorNode($result, $combinator, $nextSelector);
 139          }
 140  
 141          return new Node\SelectorNode($result, $pseudoElement);
 142      }
 143  
 144      /**
 145       * Parses next simple node (hash, class, pseudo, negation).
 146       *
 147       * @throws SyntaxErrorException
 148       */
 149      private function parseSimpleSelector(TokenStream $stream, bool $insideNegation = false): array
 150      {
 151          $stream->skipWhitespace();
 152  
 153          $selectorStart = \count($stream->getUsed());
 154          $result = $this->parseElementNode($stream);
 155          $pseudoElement = null;
 156  
 157          while (true) {
 158              $peek = $stream->getPeek();
 159              if ($peek->isWhitespace()
 160                  || $peek->isFileEnd()
 161                  || $peek->isDelimiter([',', '+', '>', '~'])
 162                  || ($insideNegation && $peek->isDelimiter([')']))
 163              ) {
 164                  break;
 165              }
 166  
 167              if (null !== $pseudoElement) {
 168                  throw SyntaxErrorException::pseudoElementFound($pseudoElement, 'not at the end of a selector');
 169              }
 170  
 171              if ($peek->isHash()) {
 172                  $result = new Node\HashNode($result, $stream->getNext()->getValue());
 173              } elseif ($peek->isDelimiter(['.'])) {
 174                  $stream->getNext();
 175                  $result = new Node\ClassNode($result, $stream->getNextIdentifier());
 176              } elseif ($peek->isDelimiter(['['])) {
 177                  $stream->getNext();
 178                  $result = $this->parseAttributeNode($result, $stream);
 179              } elseif ($peek->isDelimiter([':'])) {
 180                  $stream->getNext();
 181  
 182                  if ($stream->getPeek()->isDelimiter([':'])) {
 183                      $stream->getNext();
 184                      $pseudoElement = $stream->getNextIdentifier();
 185  
 186                      continue;
 187                  }
 188  
 189                  $identifier = $stream->getNextIdentifier();
 190                  if (\in_array(strtolower($identifier), ['first-line', 'first-letter', 'before', 'after'])) {
 191                      // Special case: CSS 2.1 pseudo-elements can have a single ':'.
 192                      // Any new pseudo-element must have two.
 193                      $pseudoElement = $identifier;
 194  
 195                      continue;
 196                  }
 197  
 198                  if (!$stream->getPeek()->isDelimiter(['('])) {
 199                      $result = new Node\PseudoNode($result, $identifier);
 200  
 201                      continue;
 202                  }
 203  
 204                  $stream->getNext();
 205                  $stream->skipWhitespace();
 206  
 207                  if ('not' === strtolower($identifier)) {
 208                      if ($insideNegation) {
 209                          throw SyntaxErrorException::nestedNot();
 210                      }
 211  
 212                      [$argument, $argumentPseudoElement] = $this->parseSimpleSelector($stream, true);
 213                      $next = $stream->getNext();
 214  
 215                      if (null !== $argumentPseudoElement) {
 216                          throw SyntaxErrorException::pseudoElementFound($argumentPseudoElement, 'inside ::not()');
 217                      }
 218  
 219                      if (!$next->isDelimiter([')'])) {
 220                          throw SyntaxErrorException::unexpectedToken('")"', $next);
 221                      }
 222  
 223                      $result = new Node\NegationNode($result, $argument);
 224                  } else {
 225                      $arguments = [];
 226                      $next = null;
 227  
 228                      while (true) {
 229                          $stream->skipWhitespace();
 230                          $next = $stream->getNext();
 231  
 232                          if ($next->isIdentifier()
 233                              || $next->isString()
 234                              || $next->isNumber()
 235                              || $next->isDelimiter(['+', '-'])
 236                          ) {
 237                              $arguments[] = $next;
 238                          } elseif ($next->isDelimiter([')'])) {
 239                              break;
 240                          } else {
 241                              throw SyntaxErrorException::unexpectedToken('an argument', $next);
 242                          }
 243                      }
 244  
 245                      if (empty($arguments)) {
 246                          throw SyntaxErrorException::unexpectedToken('at least one argument', $next);
 247                      }
 248  
 249                      $result = new Node\FunctionNode($result, $identifier, $arguments);
 250                  }
 251              } else {
 252                  throw SyntaxErrorException::unexpectedToken('selector', $peek);
 253              }
 254          }
 255  
 256          if (\count($stream->getUsed()) === $selectorStart) {
 257              throw SyntaxErrorException::unexpectedToken('selector', $stream->getPeek());
 258          }
 259  
 260          return [$result, $pseudoElement];
 261      }
 262  
 263      private function parseElementNode(TokenStream $stream): Node\ElementNode
 264      {
 265          $peek = $stream->getPeek();
 266  
 267          if ($peek->isIdentifier() || $peek->isDelimiter(['*'])) {
 268              if ($peek->isIdentifier()) {
 269                  $namespace = $stream->getNext()->getValue();
 270              } else {
 271                  $stream->getNext();
 272                  $namespace = null;
 273              }
 274  
 275              if ($stream->getPeek()->isDelimiter(['|'])) {
 276                  $stream->getNext();
 277                  $element = $stream->getNextIdentifierOrStar();
 278              } else {
 279                  $element = $namespace;
 280                  $namespace = null;
 281              }
 282          } else {
 283              $element = $namespace = null;
 284          }
 285  
 286          return new Node\ElementNode($namespace, $element);
 287      }
 288  
 289      private function parseAttributeNode(Node\NodeInterface $selector, TokenStream $stream): Node\AttributeNode
 290      {
 291          $stream->skipWhitespace();
 292          $attribute = $stream->getNextIdentifierOrStar();
 293  
 294          if (null === $attribute && !$stream->getPeek()->isDelimiter(['|'])) {
 295              throw SyntaxErrorException::unexpectedToken('"|"', $stream->getPeek());
 296          }
 297  
 298          if ($stream->getPeek()->isDelimiter(['|'])) {
 299              $stream->getNext();
 300  
 301              if ($stream->getPeek()->isDelimiter(['='])) {
 302                  $namespace = null;
 303                  $stream->getNext();
 304                  $operator = '|=';
 305              } else {
 306                  $namespace = $attribute;
 307                  $attribute = $stream->getNextIdentifier();
 308                  $operator = null;
 309              }
 310          } else {
 311              $namespace = $operator = null;
 312          }
 313  
 314          if (null === $operator) {
 315              $stream->skipWhitespace();
 316              $next = $stream->getNext();
 317  
 318              if ($next->isDelimiter([']'])) {
 319                  return new Node\AttributeNode($selector, $namespace, $attribute, 'exists', null);
 320              } elseif ($next->isDelimiter(['='])) {
 321                  $operator = '=';
 322              } elseif ($next->isDelimiter(['^', '$', '*', '~', '|', '!'])
 323                  && $stream->getPeek()->isDelimiter(['='])
 324              ) {
 325                  $operator = $next->getValue().'=';
 326                  $stream->getNext();
 327              } else {
 328                  throw SyntaxErrorException::unexpectedToken('operator', $next);
 329              }
 330          }
 331  
 332          $stream->skipWhitespace();
 333          $value = $stream->getNext();
 334  
 335          if ($value->isNumber()) {
 336              // if the value is a number, it's casted into a string
 337              $value = new Token(Token::TYPE_STRING, (string) $value->getValue(), $value->getPosition());
 338          }
 339  
 340          if (!($value->isIdentifier() || $value->isString())) {
 341              throw SyntaxErrorException::unexpectedToken('string or identifier', $value);
 342          }
 343  
 344          $stream->skipWhitespace();
 345          $next = $stream->getNext();
 346  
 347          if (!$next->isDelimiter([']'])) {
 348              throw SyntaxErrorException::unexpectedToken('"]"', $next);
 349          }
 350  
 351          return new Node\AttributeNode($selector, $namespace, $attribute, $operator, $value->getValue());
 352      }
 353  }