DependencyContainer.php

Go to the documentation of this file.

<?php

/*
 * This file is part of SwiftMailer.
 * (c) 2004-2009 Chris Corbyn
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

//@require 'Swift/DependencyException.php';

class Swift_DependencyContainer
{
  
  const TYPE_VALUE = 0x0001;
  
  const TYPE_INSTANCE = 0x0010;
  
  const TYPE_SHARED = 0x0100;
  
  const TYPE_ALIAS = 0x1000;
  
  private static $_instance = null;
  
  private $_store = array();
  
  private $_endPoint;
  
  public function __construct() { }
  
  public static function getInstance()
  {
    if (!isset(self::$_instance))
    {
      self::$_instance = new self();
    }
    return self::$_instance;
  }
  
  public function listItems()
  {
    return array_keys($this->_store);
  }
  
  public function has($itemName)
  {
    return array_key_exists($itemName, $this->_store)
      && isset($this->_store[$itemName]['lookupType']);
  }
  
  public function lookup($itemName)
  {
    if (!$this->has($itemName))
    {
      throw new Swift_DependencyException(
        'Cannot lookup dependency "' . $itemName . '" since it is not registered.'
        );
    }
    
    switch ($this->_store[$itemName]['lookupType'])
    {
      case self::TYPE_ALIAS:
        return $this->_createAlias($itemName);
      case self::TYPE_VALUE:
        return $this->_getValue($itemName);
      case self::TYPE_INSTANCE:
        return $this->_createNewInstance($itemName);
      case self::TYPE_SHARED:
        return $this->_createSharedInstance($itemName);
    }
  }
  
  public function createDependenciesFor($itemName)
  {
    $args = array();
    if (isset($this->_store[$itemName]['args']))
    {
      $args = $this->_resolveArgs($this->_store[$itemName]['args']);
    }
    return $args;
  }
  
  public function register($itemName)
  {
    $this->_store[$itemName] = array();
    $this->_endPoint =& $this->_store[$itemName];
    return $this;
  }
  
  public function asValue($value)
  {
    $endPoint =& $this->_getEndPoint();
    $endPoint['lookupType'] = self::TYPE_VALUE;
    $endPoint['value'] = $value;
    return $this;
  }
  
  public function asAliasOf($lookup)
  {
    $endPoint =& $this->_getEndPoint();
    $endPoint['lookupType'] = self::TYPE_ALIAS;
    $endPoint['ref'] = $lookup;
    return $this;
  }
  
  public function asNewInstanceOf($className)
  {
    $endPoint =& $this->_getEndPoint();
    $endPoint['lookupType'] = self::TYPE_INSTANCE;
    $endPoint['className'] = $className;
    return $this;
  }
  
  public function asSharedInstanceOf($className)
  {
    $endPoint =& $this->_getEndPoint();
    $endPoint['lookupType'] = self::TYPE_SHARED;
    $endPoint['className'] = $className;
    return $this;
  }
  
  public function withDependencies(array $lookups)
  {
    $endPoint =& $this->_getEndPoint();
    $endPoint['args'] = array();
    foreach ($lookups as $lookup)
    {
      $this->addConstructorLookup($lookup);
    }
    return $this;
  }
  
  public function addConstructorValue($value)
  {
    $endPoint =& $this->_getEndPoint();
    if (!isset($endPoint['args']))
    {
      $endPoint['args'] = array();
    }
    $endPoint['args'][] = array('type' => 'value', 'item' => $value);
    return $this;
  }
  
  public function addConstructorLookup($lookup)
  {
    $endPoint =& $this->_getEndPoint();
    if (!isset($this->_endPoint['args']))
    {
      $endPoint['args'] = array();
    }
    $endPoint['args'][] = array('type' => 'lookup', 'item' => $lookup);
    return $this;
  }
  
  // -- Private methods
  
  private function _getValue($itemName)
  {
    return $this->_store[$itemName]['value'];
  }
  
  private function _createAlias($itemName)
  {
    return $this->lookup($this->_store[$itemName]['ref']);
  }
  
  private function _createNewInstance($itemName)
  {
    $reflector = new ReflectionClass($this->_store[$itemName]['className']);
    if ($reflector->getConstructor())
    {
      return $reflector->newInstanceArgs(
        $this->createDependenciesFor($itemName)
        );
    }
    else
    {
      return $reflector->newInstance();
    }
  }
  
  private function _createSharedInstance($itemName)
  {
    if (!isset($this->_store[$itemName]['instance']))
    {
      $this->_store[$itemName]['instance'] = $this->_createNewInstance($itemName);
    }
    return $this->_store[$itemName]['instance'];
  }
  
  private function &_getEndPoint()
  {
    if (!isset($this->_endPoint))
    {
      throw new BadMethodCallException(
        'Component must first be registered by calling register()'
        );
    }
    return $this->_endPoint;
  }
  
  private function _resolveArgs(array $args)
  {
    $resolved = array();
    foreach ($args as $argDefinition)
    {
      switch ($argDefinition['type'])
      {
        case 'lookup':
          $resolved[] = $this->_lookupRecursive($argDefinition['item']);
          break;
        case 'value':
          $resolved[] = $argDefinition['item'];
          break;
      }
    }
    return $resolved;
  }
  
  private function _lookupRecursive($item)
  {
    if (is_array($item))
    {
      $collection = array();
      foreach ($item as $k => $v)
      {
        $collection[$k] = $this->_lookupRecursive($v);
      }
      return $collection;
    }
    else
    {
      return $this->lookup($item);
    }
  }
  
}