vendor/symfony/expression-language/ExpressionLanguage.php line 67

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  1. <?php
  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. */
  12. namespace Symfony\Component\ExpressionLanguage;
  14. use Psr\Cache\CacheItemPoolInterface;
  15. use Symfony\Component\Cache\Adapter\ArrayAdapter;
  17. // Help opcache.preload discover always-needed symbols
  18. class_exists(ParsedExpression::class);
  20. /**
  21. * Allows to compile and evaluate expressions written in your own DSL.
  22. *
  23. * @author Fabien Potencier <fabien@symfony.com>
  24. */
  25. class ExpressionLanguage
  26. {
  27. private $cache;
  28. private $lexer;
  29. private $parser;
  30. private $compiler;
  32. protected $functions = [];
  34. /**
  35. * @param ExpressionFunctionProviderInterface[] $providers
  36. */
  37. public function __construct(?CacheItemPoolInterface $cache = null, array $providers = [])
  38. {
  39. $this->cache = $cache ?? new ArrayAdapter();
  40. $this->registerFunctions();
  41. foreach ($providers as $provider) {
  42. $this->registerProvider($provider);
  43. }
  44. }
  46. /**
  47. * Compiles an expression source code.
  48. *
  49. * @param Expression|string $expression The expression to compile
  50. *
  51. * @return string
  52. */
  53. public function compile($expression, array $names = [])
  54. {
  55. return $this->getCompiler()->compile($this->parse($expression, $names)->getNodes())->getSource();
  56. }
  58. /**
  59. * Evaluate an expression.
  60. *
  61. * @param Expression|string $expression The expression to compile
  62. *
  63. * @return mixed
  64. */
  65. public function evaluate($expression, array $values = [])
  66. {
  67. return $this->parse($expression, array_keys($values))->getNodes()->evaluate($this->functions, $values);
  68. }
  70. /**
  71. * Parses an expression.
  72. *
  73. * @param Expression|string $expression The expression to parse
  74. *
  75. * @return ParsedExpression
  76. */
  77. public function parse($expression, array $names)
  78. {
  79. if ($expression instanceof ParsedExpression) {
  80. return $expression;
  81. }
  83. asort($names);
  84. $cacheKeyItems = [];
  86. foreach ($names as $nameKey => $name) {
  87. $cacheKeyItems[] = \is_int($nameKey) ? $name : $nameKey.':'.$name;
  88. }
  90. $cacheItem = $this->cache->getItem(rawurlencode($expression.'//'.implode('|', $cacheKeyItems)));
  92. if (null === $parsedExpression = $cacheItem->get()) {
  93. $nodes = $this->getParser()->parse($this->getLexer()->tokenize((string) $expression), $names);
  94. $parsedExpression = new ParsedExpression((string) $expression, $nodes);
  96. $cacheItem->set($parsedExpression);
  97. $this->cache->save($cacheItem);
  98. }
  100. return $parsedExpression;
  101. }
  103. /**
  104. * Validates the syntax of an expression.
  105. *
  106. * @param Expression|string $expression The expression to validate
  107. * @param array|null $names The list of acceptable variable names in the expression, or null to accept any names
  108. *
  109. * @throws SyntaxError When the passed expression is invalid
  110. */
  111. public function lint($expression, ?array $names): void
  112. {
  113. if ($expression instanceof ParsedExpression) {
  114. return;
  115. }
  117. $this->getParser()->lint($this->getLexer()->tokenize((string) $expression), $names);
  118. }
  120. /**
  121. * Registers a function.
  122. *
  123. * @param callable $compiler A callable able to compile the function
  124. * @param callable $evaluator A callable able to evaluate the function
  125. *
  126. * @throws \LogicException when registering a function after calling evaluate(), compile() or parse()
  127. *
  128. * @see ExpressionFunction
  129. */
  130. public function register(string $name, callable $compiler, callable $evaluator)
  131. {
  132. if (null !== $this->parser) {
  133. throw new \LogicException('Registering functions after calling evaluate(), compile() or parse() is not supported.');
  134. }
  136. $this->functions[$name] = ['compiler' => $compiler, 'evaluator' => $evaluator];
  137. }
  139. public function addFunction(ExpressionFunction $function)
  140. {
  141. $this->register($function->getName(), $function->getCompiler(), $function->getEvaluator());
  142. }
  144. public function registerProvider(ExpressionFunctionProviderInterface $provider)
  145. {
  146. foreach ($provider->getFunctions() as $function) {
  147. $this->addFunction($function);
  148. }
  149. }
  151. protected function registerFunctions()
  152. {
  153. $this->addFunction(ExpressionFunction::fromPhp('constant'));
  154. }
  156. private function getLexer(): Lexer
  157. {
  158. if (null === $this->lexer) {
  159. $this->lexer = new Lexer();
  160. }
  162. return $this->lexer;
  163. }
  165. private function getParser(): Parser
  166. {
  167. if (null === $this->parser) {
  168. $this->parser = new Parser($this->functions);
  169. }
  171. return $this->parser;
  172. }
  174. private function getCompiler(): Compiler
  175. {
  176. if (null === $this->compiler) {
  177. $this->compiler = new Compiler($this->functions);
  178. }
  180. return $this->compiler->reset();
  181. }
  182. }