CheckReferenceValidityPass.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\DependencyInjection\Compiler;

use Symfony\Component\DependencyInjection\Definition;
use Symfony\Component\DependencyInjection\ContainerInterface;
use Symfony\Component\DependencyInjection\Reference;
use Symfony\Component\DependencyInjection\ContainerBuilder;
use Symfony\Component\DependencyInjection\Exception\RuntimeException;
use Symfony\Component\DependencyInjection\Exception\ScopeCrossingInjectionException;
use Symfony\Component\DependencyInjection\Exception\ScopeWideningInjectionException;

/**
 * Checks the validity of references
 *
 * The following checks are performed by this pass:
 * - target definitions are not abstract
 * - target definitions are of equal or wider scope
 * - target definitions are in the same scope hierarchy
 *
 * @author Johannes M. Schmitt <schmittjoh@gmail.com>
 */
class CheckReferenceValidityPass implements CompilerPassInterface {
  private $container;
  private $currentId;
  private $currentDefinition;
  private $currentScope;
  private $currentScopeAncestors;
  private $currentScopeChildren;

  /**
   * Processes the ContainerBuilder to validate References.
   *
   * @param ContainerBuilder $container
   */
  public function process(ContainerBuilder $container) {
    $this->container = $container;
    $children = $this->container
      ->getScopeChildren();
    $ancestors = array();
    $scopes = $this->container
      ->getScopes();
    foreach ($scopes as $name => $parent) {
      $ancestors[$name] = array(
        $parent,
      );
      while (isset($scopes[$parent])) {
        $ancestors[$name][] = $parent = $scopes[$parent];
      }
    }
    foreach ($container
      ->getDefinitions() as $id => $definition) {
      if ($definition
        ->isSynthetic() || $definition
        ->isAbstract()) {
        continue;
      }
      $this->currentId = $id;
      $this->currentDefinition = $definition;
      $this->currentScope = $scope = $definition
        ->getScope();
      if (ContainerInterface::SCOPE_CONTAINER === $scope) {
        $this->currentScopeChildren = array_keys($scopes);
        $this->currentScopeAncestors = array();
      }
      elseif (ContainerInterface::SCOPE_PROTOTYPE !== $scope) {
        $this->currentScopeChildren = $children[$scope];
        $this->currentScopeAncestors = $ancestors[$scope];
      }
      $this
        ->validateReferences($definition
        ->getArguments());
      $this
        ->validateReferences($definition
        ->getMethodCalls());
      $this
        ->validateReferences($definition
        ->getProperties());
    }
  }

  /**
   * Validates an array of References.
   *
   * @param array $arguments An array of Reference objects
   *
   * @throws RuntimeException when there is a reference to an abstract definition.
   */
  private function validateReferences(array $arguments) {
    foreach ($arguments as $argument) {
      if (is_array($argument)) {
        $this
          ->validateReferences($argument);
      }
      elseif ($argument instanceof Reference) {
        $targetDefinition = $this
          ->getDefinition((string) $argument);
        if (null !== $targetDefinition && $targetDefinition
          ->isAbstract()) {
          throw new RuntimeException(sprintf('The definition "%s" has a reference to an abstract definition "%s". ' . 'Abstract definitions cannot be the target of references.', $this->currentId, $argument));
        }
        $this
          ->validateScope($argument, $targetDefinition);
      }
    }
  }

  /**
   * Validates the scope of a single Reference.
   *
   * @param Reference  $reference
   * @param Definition $definition
   *
   * @throws ScopeWideningInjectionException when the definition references a service of a narrower scope
   * @throws ScopeCrossingInjectionException when the definition references a service of another scope hierarchy
   */
  private function validateScope(Reference $reference, Definition $definition = null) {
    if (ContainerInterface::SCOPE_PROTOTYPE === $this->currentScope) {
      return;
    }
    if (!$reference
      ->isStrict()) {
      return;
    }
    if (null === $definition) {
      return;
    }
    if ($this->currentScope === ($scope = $definition
      ->getScope())) {
      return;
    }
    $id = (string) $reference;
    if (in_array($scope, $this->currentScopeChildren, true)) {
      throw new ScopeWideningInjectionException($this->currentId, $this->currentScope, $id, $scope);
    }
    if (!in_array($scope, $this->currentScopeAncestors, true)) {
      throw new ScopeCrossingInjectionException($this->currentId, $this->currentScope, $id, $scope);
    }
  }

  /**
   * Returns the Definition given an id.
   *
   * @param string $id Definition identifier
   *
   * @return Definition
   */
  private function getDefinition($id) {
    if (!$this->container
      ->hasDefinition($id)) {
      return null;
    }
    return $this->container
      ->getDefinition($id);
  }

}