<?php
/**
* This file contains classes implementing Map feature.
*
* @author Qiang Xue <[email protected]>
* @link http://www.yiiframework.com/
* @copyright Copyright © 2008-2011 Yii Software LLC
* @license http://www.yiiframework.com/license/
*/
/**
* CMap 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}.
* CMap can also be used like a regular array as follows,
* <pre>
* $map[$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
* $n=count($map); // returns the number of items in the map
* </pre>
*
* @author Qiang Xue <[email protected]>
* @version $Id: CMap.php 3153 2011-04-01 12:50:06Z qiang.xue $
* @package system.collections
* @since 1.0
*/
class CMap extends CComponent implements IteratorAggregate,ArrayAccess,Countable
{
/**
* @var array internal data storage
*/
private $_d=array();
/**
* @var boolean whether this list is read-only
*/
private $_r=false;
/**
* Constructor.
* Initializes the list with an array or an iterable object.
* @param array $data the intial data. Default is null, meaning no initialization.
* @param boolean $readOnly whether the list is read-only
* @throws CException If data is not null and neither an array nor an iterator.
*/
public function __construct($data=null,$readOnly=false)
{
if($data!==null)
$this->copyFrom($data);
$this->setReadOnly($readOnly);
}
/**
* @return boolean whether this map is read-only or not. Defaults to false.
*/
public function getReadOnly()
{
return $this->_r;
}
/**
* @param boolean $value whether this list is read-only or not
*/
protected function setReadOnly($value)
{
$this->_r=$value;
}
/**
* Returns an iterator for traversing the items in the list.
* This method is required by the interface IteratorAggregate.
* @return CMapIterator an iterator for traversing the items in the list.
*/
public function getIterator()
{
return new CMapIterator($this->_d);
}
/**
* Returns the number of items in the map.
* This method is required by Countable interface.
* @return integer number of items in the map.
*/
public function count()
{
return $this->getCount();
}
/**
* Returns the number of items in the map.
* @return integer the number of items in the map
*/
public function getCount()
{
return count($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 $key the key
* @return mixed the element at the offset, null if no element is found at the offset
*/
public function itemAt($key)
{
if(isset($this->_d[$key]))
return $this->_d[$key];
else
return null;
}
/**
* Adds an item into the map.
* Note, if the specified key already exists, the old value will be overwritten.
* @param mixed $key key
* @param mixed $value value
* @throws CException if the map is read-only
*/
public function add($key,$value)
{
if(!$this->_r)
{
if($key===null)
$this->_d[]=$value;
else
$this->_d[$key]=$value;
}
else
throw new CException(Yii::t('yii','The map is read only.'));
}
/**
* Removes an item from the map by its key.
* @param mixed $key the key of the item to be removed
* @return mixed the removed value, null if no such key exists.
* @throws CException if the map is read-only
*/
public function remove($key)
{
if(!$this->_r)
{
if(isset($this->_d[$key]))
{
$value=$this->_d[$key];
unset($this->_d[$key]);
return $value;
}
else
{
// it is possible the value is null, which is not detected by isset
unset($this->_d[$key]);
return null;
}
}
else
throw new CException(Yii::t('yii','The map is read only.'));
}
/**
* Removes all items in the map.
*/
public function clear()
{
foreach(array_keys($this->_d) as $key)
$this->remove($key);
}
/**
* @param mixed $key the key
* @return boolean whether the map contains an item with the specified key
*/
public function contains($key)
{
return isset($this->_d[$key]) || array_key_exists($key,$this->_d);
}
/**
* @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 $data the data to be copied from, must be an array or object implementing Traversable
* @throws CException If data is neither an array nor an iterator.
*/
public function copyFrom($data)
{
if(is_array($data) || $data instanceof Traversable)
{
if($this->getCount()>0)
$this->clear();
if($data instanceof CMap)
$data=$data->_d;
foreach($data as $key=>$value)
$this->add($key,$value);
}
else if($data!==null)
throw new CException(Yii::t('yii','Map data must be an array or an object implementing Traversable.'));
}
/**
* Merges iterable data into the map.
*
* Existing elements in the map will be overwritten if their keys are the same as those in the source.
* If the merge is recursive, the following algorithm is performed:
* <ul>
* <li>the map data is saved as $a, and the source data is saved as $b;</li>
* <li>if $a and $b both have an array indxed at the same string key, the arrays will be merged using this algorithm;</li>
* <li>any integer-indexed elements in $b will be appended to $a and reindxed accordingly;</li>
* <li>any string-indexed elements in $b will overwrite elements in $a with the same index;</li>
* </ul>
*
* @param mixed $data the data to be merged with, must be an array or object implementing Traversable
* @param boolean $recursive whether the merging should be recursive.
*
* @throws CException If data is neither an array nor an iterator.
*/
public function mergeWith($data,$recursive=true)
{
if(is_array($data) || $data instanceof Traversable)
{
if($data instanceof CMap)
$data=$data->_d;
if($recursive)
{
if($data instanceof Traversable)
{
$d=array();
foreach($data as $key=>$value)
$d[$key]=$value;
$this->_d=self::mergeArray($this->_d,$d);
}
else
$this->_d=self::mergeArray($this->_d,$data);
}
else
{
foreach($data as $key=>$value)
$this->add($key,$value);
}
}
else if($data!==null)
throw new CException(Yii::t('yii','Map data must be an array or an object implementing Traversable.'));
}
/**
* Merges two arrays into one recursively.
* If each array has an element with the same string key value, the latter
* will overwrite the former (different from array_merge_recursive).
* Recursive merging will be conducted if both arrays have an element of array
* type and are having the same key.
* For integer-keyed elements, the elements from the latter array will
* be appended to the former array.
* @param array $a array to be merged to
* @param array $b array to be merged from
* @return array the merged array (the original arrays are not changed.)
* @see mergeWith
*/
public static function mergeArray($a,$b)
{
foreach($b as $k=>$v)
{
if(is_integer($k))
isset($a[$k]) ? $a[]=$v : $a[$k]=$v;
else if(is_array($v) && isset($a[$k]) && is_array($a[$k]))
$a[$k]=self::mergeArray($a[$k],$v);
else
$a[$k]=$v;
}
return $a;
}
/**
* Returns whether there is an element at the specified offset.
* This method is required by the interface ArrayAccess.
* @param mixed $offset the offset to check on
* @return boolean
*/
public function offsetExists($offset)
{
return $this->contains($offset);
}
/**
* Returns the element at the specified offset.
* This method is required by the interface ArrayAccess.
* @param integer $offset the offset to retrieve element.
* @return mixed the element at the offset, null if no element is found at the offset
*/
public function offsetGet($offset)
{
return $this->itemAt($offset);
}
/**
* Sets the element at the specified offset.
* This method is required by the interface ArrayAccess.
* @param integer $offset the offset to set element
* @param mixed $item the element value
*/
public function offsetSet($offset,$item)
{
$this->add($offset,$item);
}
/**
* Unsets the element at the specified offset.
* This method is required by the interface ArrayAccess.
* @param mixed $offset the offset to unset element
*/
public function offsetUnset($offset)
{
$this->remove($offset);
}
}