일본 서바이벌

PHP로 Design Patterns 예제 - Strategy / Observer / Command 패턴을 섞다.


// http://www.ibm.com/developerworks/library/os-php-designptrns/
////////////////////////////////////////////////
////////////////////////////////////////////////

interface IStrategy
{
function filter( $record );
}

class FindAfterStrategy implements IStrategy
{
private $_name;

public function __construct( $name )
{
$this->_name = $name;
}

public function filter( $record )
{
return strcmp( $this->_name, $record ) <= 0;
}
}

class RandomStrategy implements IStrategy
{
public function filter( $record )
{
return rand( 0, 1 ) >= 0.5;
}
}

////////////////////////////////////////////////
////////////////////////////////////////////////

interface IObserver
{
function onAdded( $sender, $args );
function onDeleted( $sender, $args );
}

interface IObservable
{
function addObserver( $observer );
}

////////////////////////////////////////////////
////////////////////////////////////////////////

interface ICommand
{
function onCommand( $name, $args );
}

class CommandChain
{
private $_commands = array();

public function addCommand( $cmd )
{
$this->_commands []= $cmd;
}

public function runCommand( $name, $args )
{
foreach( $this->_commands as $cmd )
{
if ( $cmd->onCommand( $name, $args ) )
return;
}
}
}

////////////////////////////////////////////////
////////////////////////////////////////////////


class UserList implements IObservable
{
private $_list = array();
private $_observers = array();

public function addObserver( $observer )
{
$this->_observers []= $observer;
}

public function __construct( $names )
{
if ( $names != null )
{
foreach( $names as $name )
{
$this->_list []= $name;
}
}
}

public function add( $name )
{
$this->_list []= $name;
foreach( $this->_observers as $obs ) $obs->onAdded( $this, $name );
}

public function del( $name )
{
deleteFromArray( $this->_list, $name, false );
foreach( $this->_observers as $obs ) $obs->onDeleted( $this, $name );
}

public function find( $filter )
{
$recs = array();
foreach( $this->_list as $user )
{
if ( $filter->filter( $user ) ) $recs []= $user;
}
return $recs;
}
}

class UserListObserver implements IObserver
{
private $command;

public function __construct()
{
$this->command = new CommandChain();
$this->command->addCommand( new UserListCommand() );
}

public function onAdded( $sender, $args )
{
echo( "'$args' added user list\n
" );
$this->command->runCommand( 'add', $args );
}

public function onDeleted( $sender, $args )
{
echo( "'$args' deleted from user list\n
" );
$this->command->runCommand( 'del', $args );
}
}

class UserListCommand implements ICommand
{
public function onCommand( $name, $args )
{
$arrValidCommand = array( 'add', 'del' );

if ( !in_array( $name, $arrValidCommand ) ) return false;

if ( $name == 'add' ) echo( "Say to all users : added $args \n
" );
if ( $name == 'del' ) echo( "Say to all users : deleted $args \n
" );
return true;
}
}


$ul = new UserList( array( "Andy", "Jack", "Lori", "Megan" ) );
$ul->addObserver( new UserListObserver() );

$f1 = $ul->find( new FindAfterStrategy( "J" ) );
echo "

".print_r( $f1, true )."</pre>";<br /><br />$ul->add( "Lori2" );<br />$f2 = $ul->find( new FindAfterStrategy( "J" ) );<br />echo "<pre>".print_r( $f2, true )."</pre>";<br /><br />$ul->del( "Lori" );<br />$f3 = $ul->find( new FindAfterStrategy( "J" ) );<br />echo "<pre>".print_r( $f3, true )."</pre>";<br /><br />// $f2 = $ul->find( new RandomStrategy() );<br />// echo "<pre>".print_r( $f2, true )."

";

/////////////////////////////////////////////////////////
/////////////////////////////////////////////////////////

/*
* This function deletes the given element from a one-dimension array
* Parameters: $array: the array (in/out)
* $deleteIt: the value which we would like to delete
* $useOldKeys: if it is false then the function will re-index the array (from 0, 1, ...)
* if it is true: the function will keep the old keys
* Returns true, if this value was in the array, otherwise false (in this case the array is same as before)
*/
function deleteFromArray(&$array, $deleteIt, $useOldKeys = FALSE)
{
$tmpArray = array();
$found = FALSE;
foreach($array as $key => $value)
{
if($value !== $deleteIt)
{
if(FALSE === $useOldKeys)
{
$tmpArray[] = $value;
}
else
{
$tmpArray[$key] = $value;
}
}
else
{
$found = TRUE;
}
}

$array = $tmpArray;

return $found;
}
?>


PHP5 이상에서의 실행결과는 다음과 같다.

Array
(
[0] => Jack
[1] => Lori
[2] => Megan
)

'Lori2' added user list
Say to all users : added Lori2

Array
(
[0] => Jack
[1] => Lori
[2] => Megan
[3] => Lori2
)

'Lori' deleted from user list
Say to all users : deleted Lori

Array
(
[0] => Jack
[1] => Megan
[2] => Lori2
)