name : RouteCompiler.php <?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\Routing; /** * RouteCompiler compiles Route instances to CompiledRoute instances. * * @author Fabien Potencier <fabien@symfony.com> * @author Tobias Schultze <http://tobion.de> */ class RouteCompiler implements RouteCompilerInterface { const REGEX_DELIMITER = '#'; /** * This string defines the characters that are automatically considered separators in front of * optional placeholders (with default and no static text following). Such a single separator * can be left out together with the optional placeholder from matching and generating URLs. */ const SEPARATORS = '/,;.:-_~+*=@|'; /** * {@inheritDoc} * * @throws \LogicException If a variable is referenced more than once * @throws \DomainException If a variable name is numeric because PHP raises an error for such * subpatterns in PCRE and thus would break matching, e.g. "(?P<123>.+)". */ public static function compile(Route $route) { $staticPrefix = null; $hostVariables = array(); $pathVariables = array(); $variables = array(); $tokens = array(); $regex = null; $hostRegex = null; $hostTokens = array(); if ('' !== $host = $route->getHost()) { $result = self::compilePattern($route, $host, true); $hostVariables = $result['variables']; $variables = array_merge($variables, $hostVariables); $hostTokens = $result['tokens']; $hostRegex = $result['regex']; } $path = $route->getPath(); $result = self::compilePattern($route, $path, false); $staticPrefix = $result['staticPrefix']; $pathVariables = $result['variables']; $variables = array_merge($variables, $pathVariables); $tokens = $result['tokens']; $regex = $result['regex']; return new CompiledRoute( $staticPrefix, $regex, $tokens, $pathVariables, $hostRegex, $hostTokens, $hostVariables, array_unique($variables) ); } private static function compilePattern(Route $route, $pattern, $isHost) { $tokens = array(); $variables = array(); $matches = array(); $pos = 0; $defaultSeparator = $isHost ? '.' : '/'; // Match all variables enclosed in "{}" and iterate over them. But we only want to match the innermost variable // in case of nested "{}", e.g. {foo{bar}}. This in ensured because \w does not match "{" or "}" itself. preg_match_all('#\{\w+\}#', $pattern, $matches, PREG_OFFSET_CAPTURE | PREG_SET_ORDER); foreach ($matches as $match) { $varName = substr($match[0][0], 1, -1); // get all static text preceding the current variable $precedingText = substr($pattern, $pos, $match[0][1] - $pos); $pos = $match[0][1] + strlen($match[0][0]); $precedingChar = strlen($precedingText) > 0 ? substr($precedingText, -1) : ''; $isSeparator = '' !== $precedingChar && false !== strpos(static::SEPARATORS, $precedingChar); if (is_numeric($varName)) { throw new \DomainException(sprintf('Variable name "%s" cannot be numeric in route pattern "%s". Please use a different name.', $varName, $pattern)); } if (in_array($varName, $variables)) { throw new \LogicException(sprintf('Route pattern "%s" cannot reference variable name "%s" more than once.', $pattern, $varName)); } if ($isSeparator && strlen($precedingText) > 1) { $tokens[] = array('text', substr($precedingText, 0, -1)); } elseif (!$isSeparator && strlen($precedingText) > 0) { $tokens[] = array('text', $precedingText); } $regexp = $route->getRequirement($varName); if (null === $regexp) { $followingPattern = (string) substr($pattern, $pos); // Find the next static character after the variable that functions as a separator. By default, this separator and '/' // are disallowed for the variable. This default requirement makes sure that optional variables can be matched at all // and that the generating-matching-combination of URLs unambiguous, i.e. the params used for generating the URL are // the same that will be matched. Example: new Route('/{page}.{_format}', array('_format' => 'html')) // If {page} would also match the separating dot, {_format} would never match as {page} will eagerly consume everything. // Also even if {_format} was not optional the requirement prevents that {page} matches something that was originally // part of {_format} when generating the URL, e.g. _format = 'mobile.html'. $nextSeparator = self::findNextSeparator($followingPattern); $regexp = sprintf( '[^%s%s]+', preg_quote($defaultSeparator, self::REGEX_DELIMITER), $defaultSeparator !== $nextSeparator && '' !== $nextSeparator ? preg_quote($nextSeparator, self::REGEX_DELIMITER) : '' ); if (('' !== $nextSeparator && !preg_match('#^\{\w+\}#', $followingPattern)) || '' === $followingPattern) { // When we have a separator, which is disallowed for the variable, we can optimize the regex with a possessive // quantifier. This prevents useless backtracking of PCRE and improves performance by 20% for matching those patterns. // Given the above example, there is no point in backtracking into {page} (that forbids the dot) when a dot must follow // after it. This optimization cannot be applied when the next char is no real separator or when the next variable is // directly adjacent, e.g. '/{x}{y}'. $regexp .= '+'; } } $tokens[] = array('variable', $isSeparator ? $precedingChar : '', $regexp, $varName); $variables[] = $varName; } if ($pos < strlen($pattern)) { $tokens[] = array('text', substr($pattern, $pos)); } // find the first optional token $firstOptional = PHP_INT_MAX; if (!$isHost) { for ($i = count($tokens) - 1; $i >= 0; $i--) { $token = $tokens[$i]; if ('variable' === $token[0] && $route->hasDefault($token[3])) { $firstOptional = $i; } else { break; } } } // compute the matching regexp $regexp = ''; for ($i = 0, $nbToken = count($tokens); $i < $nbToken; $i++) { $regexp .= self::computeRegexp($tokens, $i, $firstOptional); } return array( 'staticPrefix' => 'text' === $tokens[0][0] ? $tokens[0][1] : '', 'regex' => self::REGEX_DELIMITER.'^'.$regexp.'$'.self::REGEX_DELIMITER.'s', 'tokens' => array_reverse($tokens), 'variables' => $variables, ); } /** * Returns the next static character in the Route pattern that will serve as a separator. * * @param string $pattern The route pattern * * @return string The next static character that functions as separator (or empty string when none available) */ private static function findNextSeparator($pattern) { if ('' == $pattern) { // return empty string if pattern is empty or false (false which can be returned by substr) return ''; } // first remove all placeholders from the pattern so we can find the next real static character $pattern = preg_replace('#\{\w+\}#', '', $pattern); return isset($pattern[0]) && false !== strpos(static::SEPARATORS, $pattern[0]) ? $pattern[0] : ''; } /** * Computes the regexp used to match a specific token. It can be static text or a subpattern. * * @param array $tokens The route tokens * @param integer $index The index of the current token * @param integer $firstOptional The index of the first optional token * * @return string The regexp pattern for a single token */ private static function computeRegexp(array $tokens, $index, $firstOptional) { $token = $tokens[$index]; if ('text' === $token[0]) { // Text tokens return preg_quote($token[1], self::REGEX_DELIMITER); } else { // Variable tokens if (0 === $index && 0 === $firstOptional) { // When the only token is an optional variable token, the separator is required return sprintf('%s(?P<%s>%s)?', preg_quote($token[1], self::REGEX_DELIMITER), $token[3], $token[2]); } else { $regexp = sprintf('%s(?P<%s>%s)', preg_quote($token[1], self::REGEX_DELIMITER), $token[3], $token[2]); if ($index >= $firstOptional) { // Enclose each optional token in a subpattern to make it optional. // "?:" means it is non-capturing, i.e. the portion of the subject string that // matched the optional subpattern is not passed back. $regexp = "(?:$regexp"; $nbTokens = count($tokens); if ($nbTokens - 1 == $index) { // Close the optional subpatterns $regexp .= str_repeat(")?", $nbTokens - $firstOptional - (0 === $firstOptional ? 1 : 0)); } } return $regexp; } } } }