vendor/symfony/routing/Symfony/Component/Routing/RouteCompiler.php

   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      * {@inheritDoc}
  33      *
  34      * @throws \LogicException  If a variable is referenced more than once
  35      * @throws \DomainException If a variable name is numeric because PHP raises an error for such
  36      *                          subpatterns in PCRE and thus would break matching, e.g. "(?P<123>.+)".
  37      */
  38     public static function compile(Route $route)
  39     {
  40         $staticPrefix = null;
  41         $hostVariables = array();
  42         $pathVariables = array();
  43         $variables = array();
  44         $tokens = array();
  45         $regex = null;
  46         $hostRegex = null;
  47         $hostTokens = array();
  48
  49         if ('' !== $host = $route->getHost()) {
  50             $result = self::compilePattern($route, $host, true);
  51
  52             $hostVariables = $result['variables'];
  53             $variables = array_merge($variables, $hostVariables);
  54
  55             $hostTokens = $result['tokens'];
  56             $hostRegex = $result['regex'];
  57         }
  58
  59         $path = $route->getPath();
  60
  61         $result = self::compilePattern($route, $path, false);
  62
  63         $staticPrefix = $result['staticPrefix'];
  64
  65         $pathVariables = $result['variables'];
  66         $variables = array_merge($variables, $pathVariables);
  67
  68         $tokens = $result['tokens'];
  69         $regex = $result['regex'];
  70
  71         return new CompiledRoute(
  72             $staticPrefix,
  73             $regex,
  74             $tokens,
  75             $pathVariables,
  76             $hostRegex,
  77             $hostTokens,
  78             $hostVariables,
  79             array_unique($variables)
  80         );
  81     }
  82
  83     private static function compilePattern(Route $route, $pattern, $isHost)
  84     {
  85         $tokens = array();
  86         $variables = array();
  87         $matches = array();
  88         $pos = 0;
  89         $defaultSeparator = $isHost ? '.' : '/';
  90
  91         // Match all variables enclosed in "{}" and iterate over them. But we only want to match the innermost variable
  92         // in case of nested "{}", e.g. {foo{bar}}. This in ensured because \w does not match "{" or "}" itself.
  93         preg_match_all('#\{\w+\}#', $pattern, $matches, PREG_OFFSET_CAPTURE | PREG_SET_ORDER);
  94         foreach ($matches as $match) {
  95             $varName = substr($match[0][0], 1, -1);
  96             // get all static text preceding the current variable
  97             $precedingText = substr($pattern, $pos, $match[0][1] - $pos);
  98             $pos = $match[0][1] + strlen($match[0][0]);
  99             $precedingChar = strlen($precedingText) > 0 ? substr($precedingText, -1) : '';
 100             $isSeparator = '' !== $precedingChar && false !== strpos(static::SEPARATORS, $precedingChar);
 101
 102             if (is_numeric($varName)) {
 103                 throw new \DomainException(sprintf('Variable name "%s" cannot be numeric in route pattern "%s". Please use a different name.', $varName, $pattern));
 104             }
 105             if (in_array($varName, $variables)) {
 106                 throw new \LogicException(sprintf('Route pattern "%s" cannot reference variable name "%s" more than once.', $pattern, $varName));
 107             }
 108
 109             if ($isSeparator && strlen($precedingText) > 1) {
 110                 $tokens[] = array('text', substr($precedingText, 0, -1));
 111             } elseif (!$isSeparator && strlen($precedingText) > 0) {
 112                 $tokens[] = array('text', $precedingText);
 113             }
 114
 115             $regexp = $route->getRequirement($varName);
 116             if (null === $regexp) {
 117                 $followingPattern = (string) substr($pattern, $pos);
 118                 // Find the next static character after the variable that functions as a separator. By default, this separator and '/'
 119                 // are disallowed for the variable. This default requirement makes sure that optional variables can be matched at all
 120                 // and that the generating-matching-combination of URLs unambiguous, i.e. the params used for generating the URL are
 121                 // the same that will be matched. Example: new Route('/{page}.{_format}', array('_format' => 'html'))
 122                 // If {page} would also match the separating dot, {_format} would never match as {page} will eagerly consume everything.
 123                 // Also even if {_format} was not optional the requirement prevents that {page} matches something that was originally
 124                 // part of {_format} when generating the URL, e.g. _format = 'mobile.html'.
 125                 $nextSeparator = self::findNextSeparator($followingPattern);
 126                 $regexp = sprintf(
 127                     '[^%s%s]+',
 128                     preg_quote($defaultSeparator, self::REGEX_DELIMITER),
 129                     $defaultSeparator !== $nextSeparator && '' !== $nextSeparator ? preg_quote($nextSeparator, self::REGEX_DELIMITER) : ''
 130                 );
 131                 if (('' !== $nextSeparator && !preg_match('#^\{\w+\}#', $followingPattern)) || '' === $followingPattern) {
 132                     // When we have a separator, which is disallowed for the variable, we can optimize the regex with a possessive
 133                     // quantifier. This prevents useless backtracking of PCRE and improves performance by 20% for matching those patterns.
 134                     // Given the above example, there is no point in backtracking into {page} (that forbids the dot) when a dot must follow
 135                     // after it. This optimization cannot be applied when the next char is no real separator or when the next variable is
 136                     // directly adjacent, e.g. '/{x}{y}'.
 137                     $regexp .= '+';
 138                 }
 139             }
 140
 141             $tokens[] = array('variable', $isSeparator ? $precedingChar : '', $regexp, $varName);
 142             $variables[] = $varName;
 143         }
 144
 145         if ($pos < strlen($pattern)) {
 146             $tokens[] = array('text', substr($pattern, $pos));
 147         }
 148
 149         // find the first optional token
 150         $firstOptional = PHP_INT_MAX;
 151         if (!$isHost) {
 152             for ($i = count($tokens) - 1; $i >= 0; $i--) {
 153                 $token = $tokens[$i];
 154                 if ('variable' === $token[0] && $route->hasDefault($token[3])) {
 155                     $firstOptional = $i;
 156                 } else {
 157                     break;
 158                 }
 159             }
 160         }
 161
 162         // compute the matching regexp
 163         $regexp = '';
 164         for ($i = 0, $nbToken = count($tokens); $i < $nbToken; $i++) {
 165             $regexp .= self::computeRegexp($tokens, $i, $firstOptional);
 166         }
 167
 168         return array(
 169             'staticPrefix' => 'text' === $tokens[0][0] ? $tokens[0][1] : '',
 170             'regex' => self::REGEX_DELIMITER.'^'.$regexp.'$'.self::REGEX_DELIMITER.'s',
 171             'tokens' => array_reverse($tokens),
 172             'variables' => $variables,
 173         );
 174     }
 175
 176     /**
 177      * Returns the next static character in the Route pattern that will serve as a separator.
 178      *
 179      * @param string $pattern The route pattern
 180      *
 181      * @return string The next static character that functions as separator (or empty string when none available)
 182      */
 183     private static function findNextSeparator($pattern)
 184     {
 185         if ('' == $pattern) {
 186             // return empty string if pattern is empty or false (false which can be returned by substr)
 187             return '';
 188         }
 189         // first remove all placeholders from the pattern so we can find the next real static character
 190         $pattern = preg_replace('#\{\w+\}#', '', $pattern);
 191
 192         return isset($pattern[0]) && false !== strpos(static::SEPARATORS, $pattern[0]) ? $pattern[0] : '';
 193     }
 194
 195     /**
 196      * Computes the regexp used to match a specific token. It can be static text or a subpattern.
 197      *
 198      * @param array   $tokens        The route tokens
 199      * @param integer $index         The index of the current token
 200      * @param integer $firstOptional The index of the first optional token
 201      *
 202      * @return string The regexp pattern for a single token
 203      */
 204     private static function computeRegexp(array $tokens, $index, $firstOptional)
 205     {
 206         $token = $tokens[$index];
 207         if ('text' === $token[0]) {
 208             // Text tokens
 209             return preg_quote($token[1], self::REGEX_DELIMITER);
 210         } else {
 211             // Variable tokens
 212             if (0 === $index && 0 === $firstOptional) {
 213                 // When the only token is an optional variable token, the separator is required
 214                 return sprintf('%s(?P<%s>%s)?', preg_quote($token[1], self::REGEX_DELIMITER), $token[3], $token[2]);
 215             } else {
 216                 $regexp = sprintf('%s(?P<%s>%s)', preg_quote($token[1], self::REGEX_DELIMITER), $token[3], $token[2]);
 217                 if ($index >= $firstOptional) {
 218                     // Enclose each optional token in a subpattern to make it optional.
 219                     // "?:" means it is non-capturing, i.e. the portion of the subject string that
 220                     // matched the optional subpattern is not passed back.
 221                     $regexp = "(?:$regexp";
 222                     $nbTokens = count($tokens);
 223                     if ($nbTokens - 1 == $index) {
 224                         // Close the optional subpatterns
 225                         $regexp .= str_repeat(")?", $nbTokens - $firstOptional - (0 === $firstOptional ? 1 : 0));
 226                     }
 227                 }
 228
 229                 return $regexp;
 230             }
 231         }
 232     }
 233 }