GoF Decoratorパターン

Decorator.php

<?php
interface Text{
    public function getText();
    public function setText($str);
}

class PlainText implements Text{
    private $textString = null;
    public function getText(){
        return $this->textString;
    }
    public function setText($str){
        $this->textString = $str;
    }
}

//基盤クラス:Textインスタンスのgetter,setterのみ
abstract class TextDecorator implements Text{
    private $text;
    public function __construct(Text $target){
        $this->text = $target;
    }
    
    //TextインスタンスのtextStringプロパティから文字列を取得
    public function getText(){
        return $this->text->getText();
    }
    
    //TextインスタンスのtextStringプロパティに文字列をセット
    public function setText($str){
        $this->text->setText($str);
    }
}

//大文字に変換
class UpperCaseText extends TextDecorator{
    public function __construct(Text $target){
        parent::__construct($target);
    }
    
    public function getText(){
        $str = parent::getText();
        $str = strtoupper($str);
        return $str;
    }
}

//全角に変換
class DoubleByteText extends TextDecorator{
    public function __construct(Text $target){
        parent::__construct($target);
    }
    
    public function getText(){
        $str = parent::getText();
        $str = mb_convert_kana($str, "RANSKV");
        return $str;
    }
}

$string = "abcあいDEFKA";
$text = new PlainText();
$text->setText($string);

//大文字に変換
$UpperCase = new UpperCaseText($text);
echo "UpperCase:" . $UpperCase->getText();

echo "\n";

//かなに変換
$DoubleByte = new DoubleByteText($text);
echo "DoubleByte:" . $DoubleByte->getText();