ReplaceAliasByActualDefinitionPass.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\ContainerBuilder;
use Symfony\Component\DependencyInjection\Reference;

/**
 * Replaces aliases with actual service definitions, effectively removing these
 * aliases.
 *
 * @author Johannes M. Schmitt <schmittjoh@gmail.com>
 */
class ReplaceAliasByActualDefinitionPass implements CompilerPassInterface {
  private $compiler;
  private $formatter;
  private $sourceId;

  /**
   * Process the Container to replace aliases with service definitions.
   *
   * @param ContainerBuilder $container
   */
  public function process(ContainerBuilder $container) {
    $this->compiler = $container
      ->getCompiler();
    $this->formatter = $this->compiler
      ->getLoggingFormatter();
    foreach ($container
      ->getAliases() as $id => $alias) {
      $aliasId = (string) $alias;
      $definition = $container
        ->getDefinition($aliasId);
      if ($definition
        ->isPublic()) {
        continue;
      }
      $definition
        ->setPublic(true);
      $container
        ->setDefinition($id, $definition);
      $container
        ->removeDefinition($aliasId);
      $this
        ->updateReferences($container, $aliasId, $id);

      // we have to restart the process due to concurrent modification of
      // the container
      $this
        ->process($container);
      break;
    }
  }

  /**
   * Updates references to remove aliases.
   *
   * @param ContainerBuilder $container The container
   * @param string           $currentId The alias identifier being replaced
   * @param string           $newId     The id of the service the alias points to
   */
  private function updateReferences($container, $currentId, $newId) {
    foreach ($container
      ->getAliases() as $id => $alias) {
      if ($currentId === (string) $alias) {
        $container
          ->setAlias($id, $newId);
      }
    }
    foreach ($container
      ->getDefinitions() as $id => $definition) {
      $this->sourceId = $id;
      $definition
        ->setArguments($this
        ->updateArgumentReferences($definition
        ->getArguments(), $currentId, $newId));
      $definition
        ->setMethodCalls($this
        ->updateArgumentReferences($definition
        ->getMethodCalls(), $currentId, $newId));
      $definition
        ->setProperties($this
        ->updateArgumentReferences($definition
        ->getProperties(), $currentId, $newId));
    }
  }

  /**
   * Updates argument references.
   *
   * @param array  $arguments An array of Arguments
   * @param string $currentId The alias identifier
   * @param string $newId     The identifier the alias points to
   */
  private function updateArgumentReferences(array $arguments, $currentId, $newId) {
    foreach ($arguments as $k => $argument) {
      if (is_array($argument)) {
        $arguments[$k] = $this
          ->updateArgumentReferences($argument, $currentId, $newId);
      }
      elseif ($argument instanceof Reference) {
        if ($currentId === (string) $argument) {
          $arguments[$k] = new Reference($newId, $argument
            ->getInvalidBehavior());
          $this->compiler
            ->addLogMessage($this->formatter
            ->formatUpdateReference($this, $this->sourceId, $currentId, $newId));
        }
      }
    }
    return $arguments;
  }

}