<?php /** * TMap, TMapIterator classes * * @author Qiang Xue <qiang.xue@gmail.com> * @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, * <code> * $map[$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 * </code> * 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 <qiang.xue@gmail.com> * @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,$value); } else throw new TInvalidOperationException('map_addition_disallowed'); } /** * Removes an item from the map by its key. * @param mixed the key of the item to be removed * @return mixed the removed value, null if no such key exists. * @throws TInvalidOperationException if the item cannot be removed */ public function remove($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,$value); } else if($data!==null) 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,$value); } else if($data!==null) 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 <qiang.xue@gmail.com> * @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; } } ?>