* @link http://www.pradosoft.com/
* @copyright Copyright © 2005 PradoSoft
* @license http://www.pradosoft.com/license/
* @version $Revision: $ $Date: $
* @package System.Collections
*/
/**
* TMap class
*
* TMap implements a collection that takes key-value pairs.
*
* You can access, add or remove an item with a key by using
* {@link itemAt}, {@link add}, and {@link remove}.
* To get the number of the items in the map, use {@link getCount}.
* TMap can also be used like a regular array as follows,
*
* $map[$key]=$value; // add a key-value pair
* unset($map[$key]); // remove the value with the specified key
* if(isset($map[$key])) // if the map contains the key
* foreach($map as $key=>$value) // traverse the items in the map
*
* Note, count($map) will always return 1. You should use {@link getCount()}
* to determine the number of items in the map.
*
* To extend TMap by doing additional operations with each added or removed item,
* you can override {@link addedItem} and {@link removedItem}.
* You can also override {@link canAddItem} and {@link canRemoveItem} to
* control whether to add or remove a particular item.
*
* @author Qiang Xue
* @version $Revision: $ $Date: $
* @package System.Collections
* @since 3.0
*/
class TMap extends TComponent implements IteratorAggregate,ArrayAccess
{
/**
* @var array internal data storage
*/
private $_d=array();
/**
* Constructor.
* Initializes the list with an array or an iterable object.
* @param array|Iterator the intial data. Default is null, meaning no initialization.
* @throws TInvalidDataTypeException If data is not null and neither an array nor an iterator.
*/
public function __construct($data=null)
{
parent::__construct();
if($data!==null)
$this->copyFrom($data);
}
/**
* Returns an iterator for traversing the items in the list.
* This method is required by the interface IteratorAggregate.
* @return Iterator an iterator for traversing the items in the list.
*/
public function getIterator()
{
return new TMapIterator($this->_d);
}
/**
* @return integer the number of items in the map
*/
public function getCount()
{
return count($this->_d);
}
/**
* @return array the key list
*/
public function getKeys()
{
return array_keys($this->_d);
}
/**
* Returns the item with the specified key.
* This method is exactly the same as {@link offsetGet}.
* @param mixed the key
* @return mixed the element at the offset, null if no element is found at the offset
*/
public function itemAt($key)
{
return isset($this->_d[$key]) ? $this->_d[$key] : null;
}
/**
* Adds an item into the map.
* Note, if the specified key already exists, the old value will be removed first.
* @param mixed key
* @param mixed value
* @throws TInvalidOperationException if the item cannot be added
*/
public function add($key,$value)
{
if($this->canAddItem($key,$value))
{
if(isset($this->_d[$key]))
$this->remove($key);
$this->_d[$key]=$value;
$this->addedItem($key,$value);
}
else
throw new TInvalidOperationException('map_item_invalid');
}
/**
* Removes an item from the map by its key.
* @param mixed the key of the item to be removed
* @return mixed the removed value, null if no such key exists.
* @throws TInvalidOperationException if the item cannot be removed
*/
public function remove($key)
{
if(isset($this->_d[$key]))
{
$value=$this->_d[$key];
if($this->canRemoveItem($key,$value))
{
unset($this->_d[$key]);
$this->removedItem($key,$value);
return $value;
}
else
throw new TInvalidOperationException('map_item_unremovable');
}
else
return null;
}
/**
* Removes all items in the map.
*/
public function clear()
{
foreach(array_keys($this->_d) as $key)
$this->remove($key);
}
/**
* @param mixed the key
* @return boolean whether the map contains an item with the specified key
*/
public function contains($key)
{
return isset($this->_d[$key]);
}
/**
* @return array the list of items in array
*/
public function toArray()
{
return $this->_d;
}
/**
* Copies iterable data into the map.
* Note, existing data in the map will be cleared first.
* @param mixed the data to be copied from, must be an array or object implementing Traversable
* @throws TInvalidDataTypeException If data is neither an array nor an iterator.
*/
public function copyFrom($data)
{
if(is_array($data) || $data instanceof Traversable)
{
if($this->getCount()>0)
$this->clear();
foreach($data as $key=>$value)
$this->add($key,$value);
}
else
throw new TInvalidDataTypeException('map_data_not_iterable');
}
/**
* Merges iterable data into the map.
* Existing data in the map will be kept and overwritten if the keys are the same.
* @param mixed the data to be merged with, must be an array or object implementing Traversable
* @throws TInvalidDataTypeException If data is neither an array nor an iterator.
*/
public function mergeWith($data)
{
if(is_array($data) || $data instanceof Traversable)
{
foreach($data as $key=>$value)
$this->add($key,$value);
}
else
throw new TInvalidDataTypeException('map_data_not_iterable');
}
/**
* Returns whether there is an element at the specified offset.
* This method is required by the interface ArrayAccess.
* @param mixed the offset to check on
* @return boolean
*/
public function offsetExists($offset)
{
return $this->contains($offset);
}
/**
* Returns the element at the specified offset.
* This method is required by the interface ArrayAccess.
* @param integer the offset to retrieve element.
* @return mixed the element at the offset, null if no element is found at the offset
*/
public function offsetGet($offset)
{
return isset($this->_d[$offset]) ? $this->_d[$offset] : null;
}
/**
* Sets the element at the specified offset.
* This method is required by the interface ArrayAccess.
* @param integer the offset to set element
* @param mixed the element value
*/
public function offsetSet($offset,$item)
{
$this->add($offset,$item);
}
/**
* Unsets the element at the specified offset.
* This method is required by the interface ArrayAccess.
* @param mixed the offset to unset element
*/
public function offsetUnset($offset)
{
$this->remove($offset);
}
/**
* This method is invoked after an item is successfully added to the map.
* You can override this method provide customized processing of the addition.
* @param string key to the item
* @param mixed the newly added item
*/
protected function addedItem($key,$item)
{
}
/**
* This method is invoked after an item is successfully removed from the map.
* You can override this method provide customized processing of the removal.
* @param string key to the item
* @param mixed the removed item
*/
protected function removedItem($key,$item)
{
}
/**
* This method is invoked before adding an item to the map.
* If it returns true, the item will be added to the map, otherwise not.
* You can override this method to decide whether a specific can be added.
* @param string key to the item
* @param mixed item to be added
* @return boolean whether the item can be added to the map
*/
protected function canAddItem($key,$item)
{
return true;
}
/**
* This method is invoked before removing an item from the map.
* If it returns true, the item will be removed from the map, otherwise not.
* You can override this method to decide whether a specific can be removed.
* @param string key to the item
* @param mixed item to be removed
* @return boolean whether the item can be removed to the map
*/
protected function canRemoveItem($key,$item)
{
return true;
}
}
/**
* TMapIterator class
*
* TMapIterator implements Iterator interface.
*
* TMapIterator is used by TMap. It allows TMap to return a new iterator
* for traversing the items in the map.
*
* @author Qiang Xue
* @version $Revision: $ $Date: $
* @package System.Collections
* @since 3.0
*/
class TMapIterator implements Iterator
{
/**
* @var array the data to be iterated through
*/
private $_d;
/**
* @var array list of keys in the map
*/
private $_keys;
/**
* @var mixed current key
*/
private $_key;
/**
* Constructor.
* @param array the data to be iterated through
*/
public function __construct(&$data)
{
$this->_d=&$data;
$this->_keys=array_keys($data);
}
/**
* Rewinds internal array pointer.
* This method is required by the interface Iterator.
*/
public function rewind()
{
$this->_key=reset($this->_keys);
}
/**
* Returns the key of the current array element.
* This method is required by the interface Iterator.
* @return mixed the key of the current array element
*/
public function key()
{
return $this->_key;
}
/**
* Returns the current array element.
* This method is required by the interface Iterator.
* @return mixed the current array element
*/
public function current()
{
return $this->_d[$this->_key];
}
/**
* Moves the internal pointer to the next array element.
* This method is required by the interface Iterator.
*/
public function next()
{
do
{
$this->_key=next($this->_keys);
}
while(!isset($this->_d[$this->_key]) && $this->_key!==false);
}
/**
* Returns whether there is an element at current position.
* This method is required by the interface Iterator.
* @return boolean
*/
public function valid()
{
return $this->_key!==false;
}
}
?>