1 <?php
  2 
  3 /*
  4  * This file is part of the ICanBoogie package.
  5  *
  6  * (c) Olivier Laviale <olivier.laviale@gmail.com>
  7  *
  8  * For the full copyright and license information, please view the LICENSE
  9  * file that was distributed with this source code.
 10  */
 11 
 12 namespace ICanBoogie;
 13 
 14 /**
 15  * Representation of a timezone.
 16  *
 17  * <pre>
 18  * <?php
 19  *
 20  * use ICanBoogie\TimeZone;
 21  *
 22  * $zone = new TimeZone('Europe/Paris');
 23  *
 24  * echo $zone;                     // "Europe/Paris"
 25  * echo $zone->offset;             // 3600
 26  * echo $zone->location;           // FR,48.86667,2.33333
 27  * echo $zone->location->latitude; // 48.86667
 28  * </pre>
 29  *
 30  * @property-read TimeZoneLocation $location Location information for the timezone.
 31  * @property-read string $name Name of the timezone.
 32  * @property-read int $offset Timezone offset from UTC.
 33  */
 34 class TimeZone extends \DateTimeZone
 35 {
 36     static private $utc_time;
 37     static private $cache;
 38 
 39     /**
 40      * Returns a timezone according to the specified source.
 41      *
 42      * If the source is already an instance of {@link Zone}, it is returned as is.
 43      *
 44      * Note: Instances created by the method are shared. That is, equivalent sources yield
 45      * the same instance.
 46      *
 47      * @param mixed $source Source of the timezone.
 48      *
 49      * @return \ICanBoogie\Time\Zone
 50      */
 51     static public function from($source)
 52     {
 53         if ($source instanceof self)
 54         {
 55             return $source;
 56         }
 57         else if ($source instanceof \DateTimeZone)
 58         {
 59             $source = $source->getName();
 60         }
 61 
 62         $source = (string) $source;
 63 
 64         if (empty(self::$cache[$source]))
 65         {
 66             self::$cache[$source] = new static($source);
 67         }
 68 
 69         return self::$cache[$source];
 70     }
 71 
 72     /**
 73      * The name of the timezone.
 74      *
 75      * Note: This variable is only used to provide information during debugging.
 76      *
 77      * @var string
 78      */
 79     private $name;
 80 
 81     /**
 82      * Location of the timezone.
 83      *
 84      * @var TimeZoneLocation
 85      */
 86     private $location;
 87 
 88     /**
 89      * Initializes the {@link $name} property.
 90      *
 91      * @param string $timezone
 92      */
 93     public function __construct($timezone)
 94     {
 95         parent::__construct($timezone);
 96 
 97         $this->name = $this->getName();
 98     }
 99 
100     /**
101      * Returns the {@link $location}, {@link $name} and {@link $offset} properties.
102      *
103      * @throws PropertyNotDefined in attempt to get an unsupported  property.
104      */
105     public function __get($property)
106     {
107         switch ($property)
108         {
109             case 'location':
110 
111                 if (!$this->location)
112                 {
113                     $this->location = TimeZoneLocation::from($this);
114                 }
115 
116                 return $this->location;
117 
118             case 'name':
119 
120                 return $this->name;
121 
122             case 'offset':
123 
124                 $utc_time = self::$utc_time;
125 
126                 if (!$utc_time)
127                 {
128                     self::$utc_time = $utc_time = new \DateTime('now', new \DateTimeZone('utc'));
129                 }
130 
131                 return $this->getOffset($utc_time);
132         }
133 
134         if (class_exists('ICanBoogie\PropertyNotDefined'))
135         {
136             throw new PropertyNotDefined(array($property, $this));
137         }
138         else
139         {
140             throw new \RuntimeException("Property no defined: $property.");
141         }
142     }
143 
144     /**
145      * Returns the name of the timezone.
146      *
147      * @return string
148      */
149     public function __toString()
150     {
151         return $this->name;
152     }
153 }