在对象中创建对象，这是一种很好的编码实践吗？ （PHP）

Question

我只是要表明我的意思，我想知道它是否是良好的编码习惯，还是应该尽量避免它？

class Connector {
    public function __constructer ($ip, $port)
    {
        $this->socket = fsockopen($ip, $port); // Forgive me, this is simply just example, never going to be used in real-life

        return $this->socket;
    }

    public function getInfo()
    {
        // return information which maybe properties of the server the ip is connected too
    }
}

// I just want the class Connector to handle the connection, and keep it running


// Query will be used for use of the application itself and I don't want to extend connector

class Query {
    protected $connection;

    public function connect ($ip, $port)
    {
        $this->connection = new Connector($ip, $port);
    }

    public function showInfo()
    {
        return echo $this->connection->getInfo();
    }
}

请理解，此代码不是用于任何用途，它只是一个更合乎逻辑的小例子，我没有在这里发布。

Answer 1

是的，这是一个很好的做法，但你可以使它更灵活：

class Query {
    protected $connection;

    public function connect (Connector $connector)
    {
        $this->connection = $connector
    }

    public function showInfo()
    {
        return $this->connection->getInfo();
    }
}

这就是我们所说的依赖注入。

更灵活的是使用界面：

interface ConnectorInterface
{
    public function __construct(array $options);
    public function showInfo();
}

然后创建一个或多个实现接口的类：

class Connector implements ConnectorInterface
{
    private $ip;
    private $port;

    public function __construct(array $options)
    {
        $this->ip = $options['ip'];
        $this->port = $options['port'];
    }

    public function getInfo()
    {
        return 'basic connector';
    }
}

class AdvancedConnector implements ConnectorInterface
{
    private $ip;
    private $port;
    private $protocol;

    public function __construct(array $options)
    {
        $this->ip = $options['ip'];
        $this->port = $options['port'];
        $this->protocol = $options['protocol'];
    }

    public function getInfo()
    {
        return 'advanced connector';
    }
}

然后接受在Query :: connect方法中实现ConnectorInterface的任何类：

class Query {
    protected $connection;

    // changed the parameter to ConnectorInterface !!!
    public function connect (ConnectorInterface $connector)
    {
        $this->connection = $connector
    }

    public function showInfo()
    {
        return echo $this->connection->getInfo();
    }
}