<?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
{
/**
* 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.
*/
public const SEPARATORS = '/,;.:-_~+*=@|';
/**
* The maximum supported length of a PCRE subpattern name
* http://pcre.org/current/doc/html/pcre2pattern.html#SEC16.
*
* @internal
*/
public const VARIABLE_MAXIMUM_LENGTH = 32;
/**
* @throws \InvalidArgumentException if a path variable is named _fragment
* @throws \LogicException if a variable is referenced more than once
* @throws \DomainException if a variable name starts with a digit or if it is too long to be successfully used as
* a PCRE subpattern
*/
public static function compile(Route $route): CompiledRoute
{
$hostVariables = [];
$variables = [];
$hostRegex = null;
$hostTokens = [];
if ('' !== $host = $route->getHost()) {
$result = self::compilePattern($route, $host, true);
$hostVariables = $result['variables'];
$variables = $hostVariables;
$hostTokens = $result['tokens'];
$hostRegex = $result['regex'];
}
$locale = $route->getDefault('_locale');
if (null !== $locale && null !== $route->getDefault('_canonical_route') && preg_quote($locale) === $route->getRequirement('_locale')) {
$requirements = $route->getRequirements();
unset($requirements['_locale']);
$route->setRequirements($requirements);
$route->setPath(str_replace('{_locale}', $locale, $route->getPath()));
}
$path = $route->getPath();
$result = self::compilePattern($route, $path, false);
$staticPrefix = $result['staticPrefix'];
$pathVariables = $result['variables'];
foreach ($pathVariables as $pathParam) {
if ('_fragment' === $pathParam) {
throw new \InvalidArgumentException(sprintf('Route pattern "%s" cannot contain "_fragment" as a path parameter.', $route->getPath()));
}
}
$variables = array_merge($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, string $pattern, bool $isHost): array
{
$tokens = [];
$variables = [];
$matches = [];
$pos = 0;
$defaultSeparator = $isHost ? '.' : '/';
$useUtf8 = preg_match('//u', $pattern);
$needsUtf8 = $route->getOption('utf8');
if (!$needsUtf8 && $useUtf8 && preg_match('/[\x80-\xFF]/', $pattern)) {
throw new \LogicException(sprintf('Cannot use UTF-8 route patterns without setting the "utf8" option for route "%s".', $route->getPath()));
}
if (!$useUtf8 && $needsUtf8) {
throw new \LogicException(sprintf('Cannot mix UTF-8 requirements with non-UTF-8 pattern "%s".', $pattern));
}
// 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\x80-\xFF]+)\}#', $pattern, $matches, \PREG_OFFSET_CAPTURE | \PREG_SET_ORDER);
foreach ($matches as $match) {
$important = $match[1][1] >= 0;
$varName = $match[2][0];
// get all static text preceding the current variable
$precedingText = substr($pattern, $pos, $match[0][1] - $pos);
$pos = $match[0][1] + \strlen($match[0][0]);
if (!\strlen($precedingText)) {
$precedingChar = '';
} elseif ($useUtf8) {
preg_match('/.$/u', $precedingText, $precedingChar);
$precedingChar = $precedingChar[0];
} else {
$precedingChar = substr($precedingText, -1);
}
$isSeparator = '' !== $precedingChar && str_contains(static::SEPARATORS, $precedingChar);
// A PCRE subpattern name must start with a non-digit. Also a PHP variable cannot start with a digit so the
// variable would not be usable as a Controller action argument.
if (preg_match('/^\d/', $varName)) {
throw new \DomainException(sprintf('Variable name "%s" cannot start with a digit 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, $varName));
}
if (\strlen($varName) > self::VARIABLE_MAXIMUM_LENGTH) {
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, $pattern));
}
if ($isSeparator && $precedingText !== $precedingChar) {
$tokens[] = ['text', substr($precedingText, 0, -\strlen($precedingChar))];
} elseif (!$isSeparator && '' !== $precedingText) {
$tokens[] = ['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}', ['_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, $useUtf8);
$regexp = sprintf(
'[^%s%s]+',
preg_quote($defaultSeparator),
$defaultSeparator !== $nextSeparator && '' !== $nextSeparator ? preg_quote($nextSeparator) : ''
);
if (('' !== $nextSeparator && !preg_match('#^\{[\w\x80-\xFF]+\}#', $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 .= '+';
}
} else {
if (!preg_match('//u', $regexp)) {
$useUtf8 = false;
} elseif (!$needsUtf8 && preg_match('/[\x80-\xFF]|(?<!\\\\)\\\\(?:\\\\\\\\)*+(?-i:X|[pP][\{CLMNPSZ]|x\{[A-Fa-f0-9]{3})/', $regexp)) {
throw new \LogicException(sprintf('Cannot use UTF-8 route requirements without setting the "utf8" option for variable "%s" in pattern "%s".', $varName, $pattern));
}
if (!$useUtf8 && $needsUtf8) {
throw new \LogicException(sprintf('Cannot mix UTF-8 requirement with non-UTF-8 charset for variable "%s" in pattern "%s".', $varName, $pattern));
}
$regexp = self::transformCapturingGroupsToNonCapturings($regexp);
}
if ($important) {
$token = ['variable', $isSeparator ? $precedingChar : '', $regexp, $varName, false, true];
} else {
$token = ['variable', $isSeparator ? $precedingChar : '', $regexp, $varName];
}
$tokens[] = $token;
$variables[] = $varName;
}
if ($pos < \strlen($pattern)) {
$tokens[] = ['text', substr($pattern, $pos)];
}
// find the first optional token
$firstOptional = \PHP_INT_MAX;
if (!$isHost) {
for ($i = \count($tokens) - 1; $i >= 0; --$i) {
$token = $tokens[$i];
// variable is optional when it is not important and has a default value
if ('variable' === $token[0] && !($token[5] ?? false) && $route->hasDefault($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);
}
$regexp = '{^'.$regexp.'$}sD'.($isHost ? 'i' : '');
// enable Utf8 matching if really required
if ($needsUtf8) {
$regexp .= 'u';
for ($i = 0, $nbToken = \count($tokens); $i < $nbToken; ++$i) {
if ('variable' === $tokens[$i][0]) {
$tokens[$i][4] = true;
}
}
}
return [
'staticPrefix' => self::determineStaticPrefix($route, $tokens),
'regex' => $regexp,
'tokens' => array_reverse($tokens),
'variables' => $variables,
];
}
/**
* Determines the longest static prefix possible for a route.
*/
private static function determineStaticPrefix(Route $route, array $tokens): string
{
if ('text' !== $tokens[0][0]) {
return ($route->hasDefault($tokens[0][3]) || '/' === $tokens[0][1]) ? '' : $tokens[0][1];
}
$prefix = $tokens[0][1];
if (isset($tokens[1][1]) && '/' !== $tokens[1][1] && false === $route->hasDefault($tokens[1][3])) {
$prefix .= $tokens[1][1];
}
return $prefix;
}
/**
* Returns the next static character in the Route pattern that will serve as a separator (or the empty string when none available).
*/
private static function findNextSeparator(string $pattern, bool $useUtf8): string
{
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
if ('' === $pattern = preg_replace('#\{[\w\x80-\xFF]+\}#', '', $pattern)) {
return '';
}
if ($useUtf8) {
preg_match('/^./u', $pattern, $pattern);
}
return str_contains(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 int $index The index of the current token
* @param int $firstOptional The index of the first optional token
*/
private static function computeRegexp(array $tokens, int $index, int $firstOptional): string
{
$token = $tokens[$index];
if ('text' === $token[0]) {
// Text tokens
return preg_quote($token[1]);
} 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]), $token[3], $token[2]);
} else {
$regexp = sprintf('%s(?P<%s>%s)', preg_quote($token[1]), $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;
}
}
}
private static function transformCapturingGroupsToNonCapturings(string $regexp): string
{
for ($i = 0; $i < \strlen($regexp); ++$i) {
if ('\\' === $regexp[$i]) {
++$i;
continue;
}
if ('(' !== $regexp[$i] || !isset($regexp[$i + 2])) {
continue;
}
if ('*' === $regexp[++$i] || '?' === $regexp[$i]) {
++$i;
continue;
}
$regexp = substr_replace($regexp, '?:', $i, 0);
++$i;
}
return $regexp;
}
}