PHP设计模式学习笔记： 命令模式（Command）

// 书本信息操纵类，包括书本的所有操作命令的方法  class BookCommandee {      private $author;      private $title;      function __construct($title_in, $author_in) {          $this->setAuthor($author_in);          $this->setTitle($title_in);      }      function getAuthor() {          return $this->author;      }      function setAuthor($author_in) {          $this->author = $author_in;      }      function getTitle() {          return $this->title;      }      function setTitle($title_in) {          $this->title = $title_in;      }      function setStarsOn() {          $this->setAuthor(str_replace(' ','*',$this->getAuthor()));          $this->setTitle(str_replace(' ','*',$this->getTitle()));      }      function setStarsOff() {          $this->setAuthor(str_replace('*',' ',$this->getAuthor()));          $this->setTitle(str_replace('*',' ',$this->getTitle()));      }      function getAuthorAndTitle() {          return $this->getTitle().' by '.$this->getAuthor();      }  }    // 抽象类，规定必须有书本操纵类属性和exexute()方法  abstract class BookCommand {      protected $bookCommandee;      function __construct($bookCommandee_in) {          $this->bookCommandee = $bookCommandee_in;      }      abstract function execute();  }    // 继承自BookCommand抽象类的专门加星标的类  class BookStarsOnCommand extends BookCommand {      function execute() {          $this->bookCommandee->setStarsOn();      }  }    // 继承自BookCommand抽象类的专门去星标的类  class BookStarsOffCommand extends BookCommand {      function execute() {          $this->bookCommandee->setStarsOff();      }  }      writeln('开始测试命令模式');    writeln('');       // 创建一个书本操纵类    $book = new BookCommandee('Design Patterns', 'Gamma, Helm, Johnson, and Vlissides');      // 可以用这个类得到它的书名等属性    writeln('创建book之后: ');    writeln($book->getAuthorAndTitle());    writeln('');       // 创建一个专门加星标的类    // 调用它的execute()方法，给书本加星标    $starsOn = new BookStarsOnCommand($book);    callCommand($starsOn);    writeln('book加星标之后: ');    writeln($book->getAuthorAndTitle());    writeln('');       // 创建一个专门去星标的类    // 调用它的execute()方法，给书本去星标    $starsOff = new BookStarsOffCommand($book);    callCommand($starsOff);    writeln('book去星标之后: ');    writeln($book->getAuthorAndTitle());    writeln('');      writeln('结束测试命令模式');       function callCommand(BookCommand $bookCommand_in) {      $bookCommand_in->execute();    }      function writeln($line_in) {      echo $line_in.PHP_EOL;    }    // 我想这个精髓就是，把针对某个类的操作命令，全部放在一个专门的类里面去，调用这个专门的命令类的执行（execute()）方法，  // 就给需要操作的类执行了相应的命令

开始测试命令模式    创建book之后:   Design Patterns by Gamma, Helm, Johnson, and Vlissides    book加星标之后:   Design*Patterns by Gamma,*Helm,*Johnson,*and*Vlissides    book去星标之后:   Design Patterns by Gamma, Helm, Johnson, and Vlissides    结束测试命令模式