PHP设计模式学习笔记： 策略模式

// 策略生成器（有点相当于工厂）  class StrategyContext {      private $strategy = NULL;       //bookList is not instantiated at construct time      public function __construct($strategy_ind_id) {          switch ($strategy_ind_id) {              case "Makeupper":                   $this->strategy = new StrategyMakeupper();              break;              case "Makeimportant":                   $this->strategy = new StrategyMakeimportant();              break;              case "Makefavorate":                   $this->strategy = new StrategyMakefavorate();              break;          }      }      public function showBookTitle($book) {        return $this->strategy->showTitle($book);      }  }    // 定义一个策略接口，让所有实现该接口的策略类都保持有showTitle()这个规范的方法  interface StrategyInterface {      public function showTitle($book_in);  }    class StrategyMakeupper implements StrategyInterface {      public function showTitle($book_in) {          $title = $book_in->getTitle();          return strtoupper($title);      }  }    class StrategyMakeimportant implements StrategyInterface {      public function showTitle($book_in) {          $title = $book_in->getTitle();          return str_replace(' ','!',$title);      }  }    class StrategyMakefavorate implements StrategyInterface {      public function showTitle($book_in) {          $title = $book_in->getTitle();          return str_replace(' ','*',$title);      }  }    class Book {      private $author;      private $title;      function __construct($title_in, $author_in) {          $this->author = $author_in;          $this->title  = $title_in;      }      function getAuthor() {          return $this->author;      }      function getTitle() {          return $this->title;      }      function getAuthorAndTitle() {          return $this->getTitle() . ' by ' . $this->getAuthor();      }  }      writeln('开始测试策略模式');    writeln('');      $book = new Book('这是书名标题《abc》  ^o^');       // 给策略生成器工厂传递一个策略参数，就得到了不同的策略对象    $strategyContextMakeupper = new StrategyContext('Makeupper');    $strategyContextMakeimportant = new StrategyContext('Makeimportant');    $strategyContextMakefavorate = new StrategyContext('Makefavorate');       writeln('测试 1 - 显示大写后的书名');    // 调用策略对象的方法都是一样的（ showBookTitle() ），给其传递的参数也是一样的（$book）    // 但因为策略对象不一样，所以结果不一样。对象不同，结果不同，结果不同的根本原因在于传递了不同的“策略参数”    writeln($strategyContextMakeupper->showBookTitle($book));    writeln('');      writeln('测试 2 - 显示标识为重要的书名');    writeln($strategyContextMakeimportant->showBookTitle($book));    writeln('');       writeln('测试 3 - 显示标识为收藏的书名');    writeln($strategyContextMakefavorate->showBookTitle($book));    writeln('');      writeln('结束测试策略模式');      function writeln($line_in) {      echo $line_in.PHP_EOL;    }

结果：

开始测试策略模式    测试 1 - 显示大写后的书名  这是书名标题《ABC》  ^O^    测试 2 - 显示标识为重要的书名  这是书名标题《abc》!!^o^    测试 3 - 显示标识为收藏的书名  这是书名标题《abc》**^o^    结束测试策略模式