php 常见的五种设计模式

1 策略模式

<?php

interface IStrategy

{

function filter($rec);

}

class Finder implements IStrategy

{

private $name;

public function __construct($name)

{

$this->_name=$name;

}

public function filter($n)

{

return strcmp($this->_name,$n) <=0;

}

}

class RandomStrategy implements IStrategy

{

public function filter( $record )

{

return rand( 0, 1 ) >= 0.5;

}

}

class UserList

{

private $_list = array();

public function __construct( $names )

{

if ( $names != null )

{

foreach( $names as $name )

{

$this->_list []= $name;

}

}

}

public function add( $name )

{

$this->_list []= $name;

}

public function find( $filter )

{

$recs = array();

foreach( $this->_list as $user )

{

if ( $filter->filter( $user ) )

$recs []= $user;

}

return $recs;

}

}

$ul = new UserList( array( "Andy", "Jack", "Lori", "Megan" ) );

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

print_r( $f1 );

$f2 = $ul->find( new RandomStrategy() );

print_r( $f2 );

?>

2 命令链模式

<?php

interface ICommand

{

function onCommand($name,$args);

}

class CommandChain

{

private $_cmds=array();

public function addCmd($cmd)

{

$this->_cmds[]=$cmd;

}

public function runCmd($name,$args)

{

foreach($this->_cmds as $v)

{

if($v->onCommand($name,$args))

return ;

}

}

}

class UserCmd implements ICommand

{

public function onCommand($name,$args)

{

if($name=='user'){

echo 'here is test run';

return true;

}

return false;

}

}

class MailCmd implements ICommand

{

public function onCommand($name,$args)

{

if($name=='mail'){

echo 'send a mail';

return true;

}

return false;

}

}

$cmdControll=new CommandChain();

$cmdControll->addCmd(new UserCmd());

$cmdControll->addCmd(new MailCmd());

$cmdControll->runCmd('user','safdsaf');

3 观察模式