PHP面向对象程序设计组合模式与装饰模式详解
发布时间：2021-01-17 10:18:35 所属栏目：PHP 来源：互联网
导读：这篇文章主要介绍了PHP面向对象程序设计组合模式与装饰模式,结合实例形式详细分析了php组合模式与装饰模式的定义、功能、使用方法与相关注意事项,需要的朋友可以参考下
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本文实例讲述了PHP面向对象程序设计组合模式与装饰模式。分享给大家供大家参考，具体如下： 组合模式定义：组合模式定义了一个单根继承体系，使具有截然不同职责的集合可以并肩工作。 一个军队的案例， 军队整合成员，输出火力 units,$unit ); } function bombardStrength() { // 火力 $ret = 0; foreach( $this->units as $unit ) { $ret += $unit->bombardStrength(); } return $ret; } } $unit1 = new Archer(); $unit2 = new LaserCannonUnit(); $army = new Army(); $army->addUnit( $unit1 ); $army->addUnit( $unit2 ); print $army->bombardStrength(); // 输出火力 ?>output: 48 军队进一步整合其他军队 units,$unit ); } function addArmy( Army $army ) { array_push( $this->armies,$army ); } function bombardStrength() { $ret = 0; foreach( $this->units as $unit ) { $ret += $unit->bombardStrength(); } foreach( $this->armies as $army ) { $ret += $army->bombardStrength(); } return $ret; } } $unit1 = new Archer(); $unit2 = new LaserCannonUnit(); $army = new Army(); $army->addUnit( $unit1 ); $army->addUnit( $unit2 ); print $army->bombardStrength(); print "n"; $army2 = clone $army; // 克隆军队 $army->addArmy( $army2 ); print $army->bombardStrength(); print "n"; ?>output: 48 96 更好的方式，支持新增，移除等等其他功能。 units,true ) ) { // $this用于调用正常的属性或方法，self调用静态的方法，属性或者常量 return; } $this->units[] = $unit; } function removeUnit( Unit $unit ) { // >= php 5.3 $this->units = array_udiff( $this->units,array( $unit ),function( $a,$b ) { return ($a === $b)?0:1; } ); // < php 5.3 // $this->units = array_udiff( $this->units,// create_function( '$a,$b','return ($a === $b)?0:1;' ) ); // 对象数组，create_function,创建函数 } function bombardStrength() { $ret = 0; foreach( $this->units as $unit ) { $ret += $unit->bombardStrength(); } return $ret; } } // quick example classes class Tank extends Unit { // 坦克 function addUnit( Unit $unit ) {} function removeUnit( Unit $unit ) {} function bombardStrength() { return 4; } } class Soldier extends Unit { // 士兵 function addUnit( Unit $unit ) {} function removeUnit( Unit $unit ) {} function bombardStrength() { return 8; } } $tank = new Tank(); $tank2 = new Tank(); $soldier = new Soldier(); $army = new Army(); $army->addUnit( $soldier ); $army->addUnit( $tank ); $army->addUnit( $tank2 ); print_r( $army ); print $army->bombardStrength()."n"; $army->removeUnit( $soldier ); print_r( $army ); print $army->bombardStrength()."n"; ?>output: Array ( [0] => Soldier Object ( ) [1] => Tank Object ( ) [2] => Tank Object ( ) ) ) 16 Army Object ( [units:Army:private] => Array ( [1] => Tank Object ( ) [2] => Tank Object ( ) ) ) 8添加异常处理 units[] = $unit; } function removeUnit( Unit $unit ) { // >= php 5.3 //$this->units = array_udiff( $this->units,// function( $a,$b ) { return ($a === $b)?0:1; } ); // < php 5.3 $this->units = array_udiff( $this->units,create_function( '$a,'return ($a === $b)?0:1;' ) ); } function bombardStrength() { $ret = 0; foreach( $this->units as $unit ) { $ret += $unit->bombardStrength(); } return $ret; } } class UnitException extends Exception {} class Archer extends Unit { function addUnit( Unit $unit ) { throw new UnitException( get_class($this)." is a leaf" ); } function removeUnit( Unit $unit ) { throw new UnitException( get_class($this)." is a leaf" ); } function bombardStrength() { return 4; } } $archer = new Archer(); $archer2 = new Archer(); $archer->addUnit( $archer2 ); ?>output: Fatal error: Uncaught exception 'UnitException' with message 'Archer is a leaf' 点评：组合模式中的一切类都共享同一个父类型，可以轻松地在设计中添加新的组合对象或局部对象，而无需大范围地修改代码。 最终的效果，逐步优化(完美)： units as $unit ) {
$ret += $unit->bombardStrength();
}
return $ret;
}
}
// create an army
$main_army = new Army();
// add some units
$main_army->addUnit( new Archer() );
$main_army->addUnit( new LaserCannonUnit() );
// create a new army
$sub_army = new Army();
// add some units
$sub_army->addUnit( new Archer() );
$sub_army->addUnit( new Archer() );
$sub_army->addUnit( new Archer() );
// add the second army to the first
$main_army->addUnit( $sub_army );
// all the calculations handled behind the scenes
print "attacking with strength: {$main_army->bombardStrength()}n";
?>
output: attacking with strength: 60 更牛逼的组合处理， units; } function removeUnit( Unit $unit ) { // >= php 5.3 //$this->units = array_udiff( $this->units,'return ($a === $b)?0:1;' ) ); } function addUnit( Unit $unit ) { if ( in_array( $unit,true ) ) { return; } $this->units[] = $unit; } } class Army extends CompositeUnit { function bombardStrength() { $ret = 0; foreach( $this->units as $unit ) { $ret += $unit->bombardStrength(); } return $ret; } } class Archer extends Unit { function bombardStrength() { return 4; } } class LaserCannonUnit extends Unit { function bombardStrength() { return 44; } } class UnitScript { static function joinExisting( Unit $newUnit,Unit $occupyingUnit ) { // 静态方法，直接通过类名来使用 $comp; if ( ! is_null( $comp = $occupyingUnit->getComposite() ) ) { // 军队合并处理 $comp->addUnit( $newUnit ); } else { // 士兵合并处理 $comp = new Army(); $comp->addUnit( $occupyingUnit ); $comp->addUnit( $newUnit ); } return $comp; } } $army1 = new Army(); $army1->addUnit( new Archer() ); $army1->addUnit( new Archer() ); $army2 = new Army(); $army2->addUnit( new Archer() ); $army2->addUnit( new Archer() ); $army2->addUnit( new LaserCannonUnit() ); $composite = UnitScript::joinExisting( $army2,$army1 ); print_r( $composite ); ?>output: Array ( [0] => Archer Object ( ) [1] => Archer Object ( ) [2] => Army Object ( [units:CompositeUnit:private] => Array ( [0] => Archer Object ( ) [1] => Archer Object ( ) [2] => LaserCannonUnit Object ( ) ) ) ) )点评：Unit 基础，CompositeUnit复合中实现add与remove。军队继承Composite，射手继承Archer。这样射手中就不会有多余的add与remove方法了。 装饰模式装饰模式帮助我们改变具体组件的功能。 看例子 wealthfactor; } } class DiamondPlains extends Plains { // 钻石地段 function getWealthFactor() { return parent::getWealthFactor() + 2; } } class PollutedPlains extends Plains { // 污染地段 function getWealthFactor() { return parent::getWealthFactor() - 4; } } $tile = new PollutedPlains(); print $tile->getWealthFactor(); ?>output: -2 点评：不具有灵活性，我们不能同时获得钻石与被污染的土地的资金情况。 装饰模式使用组合和委托而不是只使用继承来解决功能变化的问题。 看例子： wealthfactor; } } abstract class TileDecorator extends Tile { // 装饰 protected $tile; function __construct( Tile $tile ) { $this->tile = $tile; } } class DiamondDecorator extends TileDecorator { // 钻石装饰 function getWealthFactor() { return $this->tile->getWealthFactor()+2; } } class PollutionDecorator extends TileDecorator { // 污染装饰 function getWealthFactor() { return $this->tile->getWealthFactor()-4; } } $tile = new Plains(); print $tile->getWealthFactor(); // 2 $tile = new DiamondDecorator( new Plains() ); print $tile->getWealthFactor(); // 4 $tile = new PollutionDecorator( new DiamondDecorator( new Plains() )); print $tile->getWealthFactor(); // 0 ?>output: 2 4 0 点评：这个模型具有扩展性。我们不需要创建DiamondPollutionPlains对象就可以构建一个钻石被污染的对象。 （编辑：甘南站长网） 【声明】本站内容均来自网络，其相关言论仅代表作者个人观点，不代表本站立场。若无意侵犯到您的权利，请及时与联系站长删除相关内容! |
