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   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\Routing;
  13  
  14  /**
  15   * RouteCompiler compiles Route instances to CompiledRoute instances.
  16   *
  17   * @author Fabien Potencier <fabien@symfony.com>
  18   * @author Tobias Schultze <http://tobion.de>
  19   */
  20  class RouteCompiler implements RouteCompilerInterface
  21  {
  22      const REGEX_DELIMITER = '#';
  23  
  24      /**
  25       * This string defines the characters that are automatically considered separators in front of
  26       * optional placeholders (with default and no static text following). Such a single separator
  27       * can be left out together with the optional placeholder from matching and generating URLs.
  28       */
  29      const SEPARATORS = '/,;.:-_~+*=@|';
  30  
  31      /**
  32       * The maximum supported length of a PCRE subpattern name
  33       * http://pcre.org/current/doc/html/pcre2pattern.html#SEC16.
  34       *
  35       * @internal
  36       */
  37      const VARIABLE_MAXIMUM_LENGTH = 32;
  38  
  39      /**
  40       * {@inheritdoc}
  41       *
  42       * @throws \InvalidArgumentException if a path variable is named _fragment
  43       * @throws \LogicException           if a variable is referenced more than once
  44       * @throws \DomainException          if a variable name starts with a digit or if it is too long to be successfully used as
  45       *                                   a PCRE subpattern
  46       */
  47      public static function compile(Route $route)
  48      {
  49          $hostVariables = [];
  50          $variables = [];
  51          $hostRegex = null;
  52          $hostTokens = [];
  53  
  54          if ('' !== $host = $route->getHost()) {
  55              $result = self::compilePattern($route, $host, true);
  56  
  57              $hostVariables = $result['variables'];
  58              $variables = $hostVariables;
  59  
  60              $hostTokens = $result['tokens'];
  61              $hostRegex = $result['regex'];
  62          }
  63  
  64          $path = $route->getPath();
  65  
  66          $result = self::compilePattern($route, $path, false);
  67  
  68          $staticPrefix = $result['staticPrefix'];
  69  
  70          $pathVariables = $result['variables'];
  71  
  72          foreach ($pathVariables as $pathParam) {
  73              if ('_fragment' === $pathParam) {
  74                  throw new \InvalidArgumentException(sprintf('Route pattern "%s" cannot contain "_fragment" as a path parameter.', $route->getPath()));
  75              }
  76          }
  77  
  78          $variables = array_merge($variables, $pathVariables);
  79  
  80          $tokens = $result['tokens'];
  81          $regex = $result['regex'];
  82  
  83          return new CompiledRoute(
  84              $staticPrefix,
  85              $regex,
  86              $tokens,
  87              $pathVariables,
  88              $hostRegex,
  89              $hostTokens,
  90              $hostVariables,
  91              array_unique($variables)
  92          );
  93      }
  94  
  95      private static function compilePattern(Route $route, $pattern, $isHost)
  96      {
  97          $tokens = [];
  98          $variables = [];
  99          $matches = [];
 100          $pos = 0;
 101          $defaultSeparator = $isHost ? '.' : '/';
 102          $useUtf8 = preg_match('//u', $pattern);
 103          $needsUtf8 = $route->getOption('utf8');
 104  
 105          if (!$needsUtf8 && $useUtf8 && preg_match('/[\x80-\xFF]/', $pattern)) {
 106              $needsUtf8 = true;
 107              @trigger_error(sprintf('Using UTF-8 route patterns without setting the "utf8" option is deprecated since Symfony 3.2 and will throw a LogicException in 4.0. Turn on the "utf8" route option for pattern "%s".', $pattern), \E_USER_DEPRECATED);
 108          }
 109          if (!$useUtf8 && $needsUtf8) {
 110              throw new \LogicException(sprintf('Cannot mix UTF-8 requirements with non-UTF-8 pattern "%s".', $pattern));
 111          }
 112  
 113          // Match all variables enclosed in "{}" and iterate over them. But we only want to match the innermost variable
 114          // in case of nested "{}", e.g. {foo{bar}}. This in ensured because \w does not match "{" or "}" itself.
 115          preg_match_all('#\{\w+\}#', $pattern, $matches, \PREG_OFFSET_CAPTURE | \PREG_SET_ORDER);
 116          foreach ($matches as $match) {
 117              $varName = substr($match[0][0], 1, -1);
 118              // get all static text preceding the current variable
 119              $precedingText = substr($pattern, $pos, $match[0][1] - $pos);
 120              $pos = $match[0][1] + \strlen($match[0][0]);
 121  
 122              if (!\strlen($precedingText)) {
 123                  $precedingChar = '';
 124              } elseif ($useUtf8) {
 125                  preg_match('/.$/u', $precedingText, $precedingChar);
 126                  $precedingChar = $precedingChar[0];
 127              } else {
 128                  $precedingChar = substr($precedingText, -1);
 129              }
 130              $isSeparator = '' !== $precedingChar && false !== strpos(static::SEPARATORS, $precedingChar);
 131  
 132              // A PCRE subpattern name must start with a non-digit. Also a PHP variable cannot start with a digit so the
 133              // variable would not be usable as a Controller action argument.
 134              if (preg_match('/^\d/', $varName)) {
 135                  throw new \DomainException(sprintf('Variable name "%s" cannot start with a digit in route pattern "%s". Please use a different name.', $varName, $pattern));
 136              }
 137              if (\in_array($varName, $variables)) {
 138                  throw new \LogicException(sprintf('Route pattern "%s" cannot reference variable name "%s" more than once.', $pattern, $varName));
 139              }
 140  
 141              if (\strlen($varName) > self::VARIABLE_MAXIMUM_LENGTH) {
 142                  throw new \DomainException(sprintf('Variable name "%s" cannot be longer than %d characters in route pattern "%s". Please use a shorter name.', $varName, self::VARIABLE_MAXIMUM_LENGTH, $pattern));
 143              }
 144  
 145              if ($isSeparator && $precedingText !== $precedingChar) {
 146                  $tokens[] = ['text', substr($precedingText, 0, -\strlen($precedingChar))];
 147              } elseif (!$isSeparator && \strlen($precedingText) > 0) {
 148                  $tokens[] = ['text', $precedingText];
 149              }
 150  
 151              $regexp = $route->getRequirement($varName);
 152              if (null === $regexp) {
 153                  $followingPattern = (string) substr($pattern, $pos);
 154                  // Find the next static character after the variable that functions as a separator. By default, this separator and '/'
 155                  // are disallowed for the variable. This default requirement makes sure that optional variables can be matched at all
 156                  // and that the generating-matching-combination of URLs unambiguous, i.e. the params used for generating the URL are
 157                  // the same that will be matched. Example: new Route('/{page}.{_format}', ['_format' => 'html'])
 158                  // If {page} would also match the separating dot, {_format} would never match as {page} will eagerly consume everything.
 159                  // Also even if {_format} was not optional the requirement prevents that {page} matches something that was originally
 160                  // part of {_format} when generating the URL, e.g. _format = 'mobile.html'.
 161                  $nextSeparator = self::findNextSeparator($followingPattern, $useUtf8);
 162                  $regexp = sprintf(
 163                      '[^%s%s]+',
 164                      preg_quote($defaultSeparator, self::REGEX_DELIMITER),
 165                      $defaultSeparator !== $nextSeparator && '' !== $nextSeparator ? preg_quote($nextSeparator, self::REGEX_DELIMITER) : ''
 166                  );
 167                  if (('' !== $nextSeparator && !preg_match('#^\{\w+\}#', $followingPattern)) || '' === $followingPattern) {
 168                      // When we have a separator, which is disallowed for the variable, we can optimize the regex with a possessive
 169                      // quantifier. This prevents useless backtracking of PCRE and improves performance by 20% for matching those patterns.
 170                      // Given the above example, there is no point in backtracking into {page} (that forbids the dot) when a dot must follow
 171                      // after it. This optimization cannot be applied when the next char is no real separator or when the next variable is
 172                      // directly adjacent, e.g. '/{x}{y}'.
 173                      $regexp .= '+';
 174                  }
 175              } else {
 176                  if (!preg_match('//u', $regexp)) {
 177                      $useUtf8 = false;
 178                  } elseif (!$needsUtf8 && preg_match('/[\x80-\xFF]|(?<!\\\\)\\\\(?:\\\\\\\\)*+(?-i:X|[pP][\{CLMNPSZ]|x\{[A-Fa-f0-9]{3})/', $regexp)) {
 179                      $needsUtf8 = true;
 180                      @trigger_error(sprintf('Using UTF-8 route requirements without setting the "utf8" option is deprecated since Symfony 3.2 and will throw a LogicException in 4.0. Turn on the "utf8" route option for variable "%s" in pattern "%s".', $varName, $pattern), \E_USER_DEPRECATED);
 181                  }
 182                  if (!$useUtf8 && $needsUtf8) {
 183                      throw new \LogicException(sprintf('Cannot mix UTF-8 requirement with non-UTF-8 charset for variable "%s" in pattern "%s".', $varName, $pattern));
 184                  }
 185              }
 186  
 187              $tokens[] = ['variable', $isSeparator ? $precedingChar : '', $regexp, $varName];
 188              $variables[] = $varName;
 189          }
 190  
 191          if ($pos < \strlen($pattern)) {
 192              $tokens[] = ['text', substr($pattern, $pos)];
 193          }
 194  
 195          // find the first optional token
 196          $firstOptional = \PHP_INT_MAX;
 197          if (!$isHost) {
 198              for ($i = \count($tokens) - 1; $i >= 0; --$i) {
 199                  $token = $tokens[$i];
 200                  if ('variable' === $token[0] && $route->hasDefault($token[3])) {
 201                      $firstOptional = $i;
 202                  } else {
 203                      break;
 204                  }
 205              }
 206          }
 207  
 208          // compute the matching regexp
 209          $regexp = '';
 210          for ($i = 0, $nbToken = \count($tokens); $i < $nbToken; ++$i) {
 211              $regexp .= self::computeRegexp($tokens, $i, $firstOptional);
 212          }
 213          $regexp = self::REGEX_DELIMITER.'^'.$regexp.'$'.self::REGEX_DELIMITER.'sD'.($isHost ? 'i' : '');
 214  
 215          // enable Utf8 matching if really required
 216          if ($needsUtf8) {
 217              $regexp .= 'u';
 218              for ($i = 0, $nbToken = \count($tokens); $i < $nbToken; ++$i) {
 219                  if ('variable' === $tokens[$i][0]) {
 220                      $tokens[$i][] = true;
 221                  }
 222              }
 223          }
 224  
 225          return [
 226              'staticPrefix' => self::determineStaticPrefix($route, $tokens),
 227              'regex' => $regexp,
 228              'tokens' => array_reverse($tokens),
 229              'variables' => $variables,
 230          ];
 231      }
 232  
 233      /**
 234       * Determines the longest static prefix possible for a route.
 235       *
 236       * @return string The leading static part of a route's path
 237       */
 238      private static function determineStaticPrefix(Route $route, array $tokens)
 239      {
 240          if ('text' !== $tokens[0][0]) {
 241              return ($route->hasDefault($tokens[0][3]) || '/' === $tokens[0][1]) ? '' : $tokens[0][1];
 242          }
 243  
 244          $prefix = $tokens[0][1];
 245  
 246          if (isset($tokens[1][1]) && '/' !== $tokens[1][1] && false === $route->hasDefault($tokens[1][3])) {
 247              $prefix .= $tokens[1][1];
 248          }
 249  
 250          return $prefix;
 251      }
 252  
 253      /**
 254       * Returns the next static character in the Route pattern that will serve as a separator.
 255       *
 256       * @param string $pattern The route pattern
 257       * @param bool   $useUtf8 Whether the character is encoded in UTF-8 or not
 258       *
 259       * @return string The next static character that functions as separator (or empty string when none available)
 260       */
 261      private static function findNextSeparator($pattern, $useUtf8)
 262      {
 263          if ('' == $pattern) {
 264              // return empty string if pattern is empty or false (false which can be returned by substr)
 265              return '';
 266          }
 267          // first remove all placeholders from the pattern so we can find the next real static character
 268          if ('' === $pattern = preg_replace('#\{\w+\}#', '', $pattern)) {
 269              return '';
 270          }
 271          if ($useUtf8) {
 272              preg_match('/^./u', $pattern, $pattern);
 273          }
 274  
 275          return false !== strpos(static::SEPARATORS, $pattern[0]) ? $pattern[0] : '';
 276      }
 277  
 278      /**
 279       * Computes the regexp used to match a specific token. It can be static text or a subpattern.
 280       *
 281       * @param array $tokens        The route tokens
 282       * @param int   $index         The index of the current token
 283       * @param int   $firstOptional The index of the first optional token
 284       *
 285       * @return string The regexp pattern for a single token
 286       */
 287      private static function computeRegexp(array $tokens, $index, $firstOptional)
 288      {
 289          $token = $tokens[$index];
 290          if ('text' === $token[0]) {
 291              // Text tokens
 292              return preg_quote($token[1], self::REGEX_DELIMITER);
 293          } else {
 294              // Variable tokens
 295              if (0 === $index && 0 === $firstOptional) {
 296                  // When the only token is an optional variable token, the separator is required
 297                  return sprintf('%s(?P<%s>%s)?', preg_quote($token[1], self::REGEX_DELIMITER), $token[3], $token[2]);
 298              } else {
 299                  $regexp = sprintf('%s(?P<%s>%s)', preg_quote($token[1], self::REGEX_DELIMITER), $token[3], $token[2]);
 300                  if ($index >= $firstOptional) {
 301                      // Enclose each optional token in a subpattern to make it optional.
 302                      // "?:" means it is non-capturing, i.e. the portion of the subject string that
 303                      // matched the optional subpattern is not passed back.
 304                      $regexp = "(?:$regexp";
 305                      $nbTokens = \count($tokens);
 306                      if ($nbTokens - 1 == $index) {
 307                          // Close the optional subpatterns
 308                          $regexp .= str_repeat(')?', $nbTokens - $firstOptional - (0 === $firstOptional ? 1 : 0));
 309                      }
 310                  }
 311  
 312                  return $regexp;
 313              }
 314          }
 315      }
 316  }