cs Strategy

This commit is contained in:
Dominik Liebler 2013-09-12 11:37:03 +02:00
parent efd71b48e1
commit 3808eab0a0
6 changed files with 149 additions and 111 deletions

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<?php
namespace DesignPatterns\Strategy;
/**
* Class ComparatorInterface
*/
interface ComparatorInterface
{
/**
* @param mixed $a
* @param mixed $b
*
* @return bool
*/
public function compare($a, $b);
}

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<?php
namespace DesignPatterns\Strategy;
/**
* Class DateComparator
*/
class DateComparator implements ComparatorInterface
{
/**
* {@inheritdoc}
*/
public function compare($a, $b)
{
$aDate = strtotime($a['date']);
$bDate = strtotime($b['date']);
if ($aDate == $bDate) {
return 0;
} else {
return $aDate < $bDate ? -1 : 1;
}
}
}

21
Strategy/IdComparator.php Normal file
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<?php
namespace DesignPatterns\Strategy;
/**
* Class IdComparator
*/
class IdComparator implements ComparatorInterface
{
/**
* {@inheritdoc}
*/
public function compare($a, $b)
{
if ($a['id'] == $b['id']) {
return 0;
} else {
return $a['id'] < $b['id'] ? -1 : 1;
}
}
}

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<?php
namespace DesignPatterns\Strategy;
/**
* Class ObjectCollection
*/
class ObjectCollection
{
/**
* @var array
*/
private $elements;
/**
* @var ComparatorInterface
*/
private $comparator;
/**
* @param array $elements
*/
public function __construct(array $elements = array())
{
$this->elements = $elements;
}
/**
* @return array
*/
public function sort()
{
$callback = array($this->comparator, 'compare');
uasort($this->elements, $callback);
return $this->elements;
}
/**
* @param ComparatorInterface $comparator
*
* @return void
*/
public function setComparator(ComparatorInterface $comparator)
{
$this->comparator = $comparator;
}
}

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@ -1,111 +0,0 @@
<?php
namespace DesignPatterns;
/**
* strategy pattern
*
* Terminology:
* - Context
* - Strategy
* - Concrete Strategy
*
* Purpose:
* to separate strategies and to enable fast switching between them.
* also this pattern is a good alternative to inheritance (instead of having an abstract class that is extended)
*
* Examples:
* - sorting a list of objects, one strategy by date, the other by id
* - simplify unit testing: e.g. switching between file and in-memory storage
*
*/
interface Comparator
{
/**
* @abstract
* @param object $a
* @param object $b
* @return bool
*/
public function compare($a, $b);
}
class ObjectCollection
{
private $_elements;
private $_comparator;
/**
* @param array $elements
*/
public function __construct(array $elements = array())
{
$this->_elements = $elements;
}
/**
* @return array
*/
public function sort()
{
$callback = array($this->_comparator, 'compare');
uasort($this->_elements, $callback);
return $this->_elements;
}
/**
* @param Comparator $comparator
* @return void
*/
public function setComparator(Comparator $comparator)
{
$this->_comparator = $comparator;
}
}
class IdComparator implements Comparator
{
public function compare($a, $b)
{
if ($a['id'] == $b['id']) {
return 0;
} else {
return $a['id'] < $b['id'] ? -1 : 1;
}
}
}
class DateComparator implements Comparator
{
public function compare($a, $b)
{
$aDate = strtotime($a['date']);
$bDate = strtotime($b['date']);
if ($aDate == $bDate) {
return 0;
} else {
return $aDate < $bDate ? -1 : 1;
}
}
}
$elements = array(
array(
'id' => 2,
'date' => '2011-01-01',
),
array(
'id' => 1,
'date' => '2011-02-01'
)
);
$collection = new ObjectCollection($elements);
$collection->setComparator(new IdComparator());
$collection->sort();
$collection->setComparator(new DateComparator());
$collection->sort();

39
Strategy/index.php Normal file
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<?php
namespace DesignPatterns\Strategy;
/**
* strategy pattern
*
* Terminology:
* - Context
* - Strategy
* - Concrete Strategy
*
* Purpose:
* to separate strategies and to enable fast switching between them.
* also this pattern is a good alternative to inheritance (instead of having an abstract class that is extended)
*
* Examples:
* - sorting a list of objects, one strategy by date, the other by id
* - simplify unit testing: e.g. switching between file and in-memory storage
*
*/
$elements = array(
array(
'id' => 2,
'date' => '2011-01-01',
),
array(
'id' => 1,
'date' => '2011-02-01'
)
);
$collection = new ObjectCollection($elements);
$collection->setComparator(new IdComparator());
$collection->sort();
$collection->setComparator(new DateComparator());
$collection->sort();