实现功能:

用户发布的一部电影在审核时,和审核通过后,对应的操作各不相同.

 

一.定义两个异常

/** * 定义一个权限拒绝异常 * Class PermissionDeniedException */class PermissionDeniedException extends \Exception{    protected $message    = '权限拒绝';    protected $code       = 2000;    public function __construct()    {        parent::__construct($this->message, $this->code);    }}

　　

/** * 数据未发现异常 * Class NotFoundMovieException */class NotFoundMovieException extends \Exception{    protected $message    = '数据未发现';    protected $code       = 404;    public function __construct()    {        parent::__construct($this->message, $this->code);    }}

　　

 

二.定义一个数据类(模拟从数据库获取数据)

/** * 电影类 * Class DbMovie */class DbMovie{    const MOVIES = [        ['id' => 1, 'uid' => 10, 'title' => '铁胆雄心', 'state' => 2]    ];    /**     * 模拟查找数据     * @param $id     * @return bool|mixed     */    public function find($id)    {        foreach (self::MOVIES as $movie) {            if ($movie['id'] === $id) {                return $movie;            }        }        return false;    }}

　　

三.定义状态接口

/** * 状态接口 * Interface MovieStateInterface */interface MovieStateInterface{    public function show($requestUid);    public function delete($requestUid);    public function edit($requestUid);    public function update($requestUid);}

　　

四.定义一个虚拟电影基类

/** * Class MovieState */abstract class MovieState{    protected $movie;    public function __construct($movie)    {        $this->movie = $movie;    }}

　　

五.定义等待审核状态的电影

/** * 等待审核中的电影 * Class ReviewMovie */class ReviewMovie extends MovieState implements MovieStateInterface{    // 允许发布者自己可以查看    public function show($requestUid)    {        if ($requestUid === $this->movie['uid']) {            return $this->movie;        } else {            throw new PermissionDeniedException();        }    }    public function delete($requestUid)    {        throw new PermissionDeniedException();    }    public function edit($requestUid)    {        throw new PermissionDeniedException();    }    public function update($requestUid)    {        throw new PermissionDeniedException();    }}

　　

五.定义审核通过后的电影

/** * 审核通过的电影: 允许发布者查看,删除,编辑和更新,其余人只可查看 * Class NomarlMovie */class NormalMovie extends MovieState implements MovieStateInterface{    public function show($requestUid)    {        return $this->movie;    }    public function delete($requestUid)    {        if ($requestUid === $this->movie['uid']) {            echo '删除成功
';        } else {            throw new PermissionDeniedException();        }    }    public function edit($requestUid)    {        if ($requestUid === $this->movie['uid']) {            echo '可以编辑
';        } else {            throw new PermissionDeniedException();        }    }    public function update($requestUid)    {        if ($requestUid === $this->movie['uid']) {            echo '更新成功
';            return true;        } else {            throw new PermissionDeniedException();        }    }}

　　

六.状态上下文类

class Context{    // 所有状态码对应的状态类    const MOVIE_STATES = [        1 => ReviewMovie::class,        2 => NormalMovie::class,    ];    // 状态码    private $state;    // 电影    private $movie;    // 状态对象    private $movieState;    public function __construct($movieId, $uid)    {        $this->uid = $uid;        $movieModel = new DbMovie();        $this->movie      = $movieModel->find($movieId);        if ($this->movie === false) {            throw new NotFoundMovieException();        }        // 状态码的修改根据保存在数据库中电影的状态来改变        $this->state = $this->movie['state'];        // 切换状态码        $this->setMovieState();    }    protected function setMovieState()    {        $currentStateClass          = self::MOVIE_STATES[$this->state];        $this->movieState           = new $currentStateClass($this->movie);    }    public function show()    {        return $this->movieState->show($this->uid);    }    public function delete()    {        return $this->movieState->delete($this->uid);    }    public function edit()    {        return $this->movieState->edit($this->uid);    }    public function update()    {        return $this->movieState->update($this->uid);    }}

　　

七.调用

try{    $client = new Context($movieId = 1, $uid = 10);    var_dump($client->show());    var_dump($client->update());} catch (NotFoundMovieException $e) {    echo $e->getMessage();} catch (PermissionDeniedException $e) {    echo $e->getMessage();} catch (\Exception $e) {    echo $e->getMessage();}