interface/modules/zend_modules/library/Zend/Di/ServiceLocator.php

   1 <?php
   2 /**
   3  * Zend Framework (http://framework.zend.com/)
   4  *
   5  * @link      http://github.com/zendframework/zf2 for the canonical source repository
   6  * @copyright Copyright (c) 2005-2015 Zend Technologies USA Inc. (http://www.zend.com)
   7  * @license   http://framework.zend.com/license/new-bsd New BSD License
   8  */
   9
  10 namespace Zend\Di;
  11
  12 use Closure;
  13
  14 /**
  15  * Simple service locator implementation capable of using closures to generate instances
  16  */
  17 class ServiceLocator implements ServiceLocatorInterface
  18 {
  19     /**
  20      * Map of service names to methods
  21      *
  22      * As an example, you might define a getter method "getFoo", and map it to
  23      * the service name "foo":
  24      *
  25      * <code>
  26      * protected $map = array('foo' => 'getFoo');
  27      * </code>
  28      *
  29      * When encountered, the return value of that method will be used.
  30      *
  31      * Methods mapped in this way may expect a single, array argument, the
  32      * $params passed to {@link get()}, if any.
  33      *
  34      * @var array
  35      */
  36     protected $map = array();
  37
  38     /**
  39      * Registered services and cached values
  40      *
  41      * @var array
  42      */
  43     protected $services = array();
  44
  45     /**
  46      * {@inheritDoc}
  47      */
  48     public function set($name, $service)
  49     {
  50         $this->services[$name] = $service;
  51
  52         return $this;
  53     }
  54
  55     /**
  56      * Retrieve a registered service
  57      *
  58      * Tests first if a value is registered for the service, and, if so,
  59      * returns it.
  60      *
  61      * If the value returned is a non-object callback or closure, the return
  62      * value is retrieved, stored, and returned. Parameters passed to the method
  63      * are passed to the callback, but only on the first retrieval.
  64      *
  65      * If the service requested matches a method in the method map, the return
  66      * value of that method is returned. Parameters are passed to the matching
  67      * method.
  68      *
  69      * @param  string $name
  70      * @param  array  $params
  71      * @return mixed
  72      */
  73     public function get($name, array $params = array())
  74     {
  75         if (!isset($this->services[$name])) {
  76             if (!isset($this->map[$name])) {
  77                 return;
  78             }
  79             $method = $this->map[$name];
  80
  81             return $this->$method($params);
  82         }
  83
  84         $service = $this->services[$name];
  85         if ($service instanceof Closure
  86             || (!is_object($service) && is_callable($service))
  87         ) {
  88             $this->services[$name] = $service = call_user_func_array($service, $params);
  89         }
  90
  91         return $service;
  92     }
  93 }