关于php:php设计模式八装饰器模式

装璜器模式

1. 动静的增加批改类性能
2. 一个类提供了一项性能，如果要在批改并增加额定的性能，传统计划须要写一个子类继承，并从新实现类办法
3. 应用装璜器模式，仅须要在运行时减少一个装璜器对象

// 例如批改Canvas的draw办法


class Canvas {
    private $data;
    private $decorators; // 用于保留所有装璜器
    
    public function init($hei,$wid){
        for($i=0;$i<$hei;$i++){
            for($i=0;$i<$wid;$i++){
                $data[$i][$j] = "*";
            }
        }
        
        $this->data = $data;
    }
    
    
    public function rect($a1,$a2,$b1,$b2) {
        foreach($this->data as $k1->$line){
            if($k1<$a1 or $k1 > $a2) continue;
            foreach($line as $k2 => $item){
                if($k2<$b2 or $k2> $b2) contine;
                $this->data[$k1][$2] = ' ';
            }
        }
    }
    
    public function draw(){
        foreach ($this->data as 
        $line){
            foreach ($lien as $item) {
                echo  $item;
            }
            echo PHP_EOL:
        }
    }
    
    
    // 用于减少装璜器
    public function addDecorator(Decorator $decorator){
        $this->decorators[] = $decorator;
    }
    
    // 前置执行
    public function before(){
        foreach($this->decorators as $decorator) {
            $decorator->before();
        }
    }
    
    
    
    public function after(){
        $decorators = array_reserse($this->decorator);
        foreach($decorators as $decorator) {
            $decorator->before();
        }
    }
}


// 装璜器接口  在某个办法之前，之后退出额定操作
interface Decorator {
    public function beforDraw();
    public function afterDraw();
}


class ColorDecorator implements Decorator {
    private $color;
    
    public function __construct($color){
        $this->color = $color;
    }
    

    public function before(){
        echo 'before'.$this->color;
    }
    
    public function after(){
        echo 'after';
    }
}

$c = new Canvas();
$c->addDecorator(new ColorDecorator('red'));  // 减少不同的装璜器，进行不同的批改
$c->rect(1,6,2,12);
$c->draw();