存储或使用对象状态后更改对象 [英] changed object after storage or object-state used

问题描述

示例:

class UserStorage {
    public function addUser(User $user) { //saves to db }
}

class User {
    public function setName($name);
}

如果我将用户添加到用户存储中，然后又更改该用户对象该怎么办?在这种情况下，您可能会争辩说，仅应将用户对象存储在__destruct上.但这有时不是一个选择(例如，假设用户随后被显示和更新).

What if I add a user to the user storage and later change that user object? In this case you might argue that user objects only should be stored on __destruct. But sometimes this isn't an option (eg imagine the user is displayed and updated afterwards).

推荐答案

隐式写入数据库可能不是一个好主意.那应该是一个明确的，受控的操作.

Implicit writes to the database are probably a bad idea. That should be an explicit, controlled operation.

您的模式对我来说有点奇怪，但是我认为这是您想要的方式

Your pattern is a little weird to me, but I think this how you'd want to do it

class UserStorage
{
    const ACTION_INSERT = 'INSERT';
    const ACTION_UPDATE = 'UDPATE';

    public function addUser(User $user)
    {
        $this->saveUser($user, self::ACTION_INSERT);
    }

    public function updateUser(User $user)
    {
        $this->saveUser($user, self::ACTION_UPDATE);
    }

    protected function saveUser(User $user, $action)
    {
        switch ($action) {
            case self::ACTION_INSERT:
                //  INSERT query
                break;
            case self::ACTION_UPDATE:
                //  UPDATE query
                break;
            default:
                throw new Exception('Unsupported action');
        }
    }
}

class User
{
    public function setName($name)
    {
        // whatever
    }
}

$userStorage = new UserStorage();
$user = new User();

$userStorage->addUser($user);

$user->setName('Peter');

try {
    $userStorage->updateUser($user);
} catch (Exception $e) {
    echo "There was an error saving this user: " . $e->getMessage();
}

但就我个人而言，我并不为此类设计感到疯狂.有一些为此而建立的模式，这些模式不太容易混淆，例如 ActiveRecord .

But Personally I'm not crazy about this class design. There are some well-established patterns for this that are less confusing, such as ActiveRecord.

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