private property vs getProperty with static variable

[koen]

Suppose you're working in a database class and every method in this class needs the database connection. A common solution is to to use somethink like this

 

private $db;

public method getPosts()
{
    $db = $this->getConnection();
    $db->execute( // some sql here);
}

private method getConnection()
{
    if (is_null($this->db) $this->db = // stuff to get connection
    return $this->db;
}

 

This doesn't prevent methods from calling $this->db directly. Encapsulation is mostly viewed between objects but not in the object itself.  To prevent methods from accessing $this->db a solution would be the following:

 

private method getConnection()
{
    static $db;
    if (is_null($db) $db = // stuff to get connection
    return $db;
}

 

Is there a reason the first one is used and not the second one?

[448191]

I don't see any big problems with that, given that you indeed want the variable to be static.

 

Ie, "static $db" does not (more or less - it's more confined) equal "private $db", but rather "static private $db".

 

There is one tiny issue though: the presence of the variable is less transparent. But, if you can live with that, and it's worth the added level of encapsulation, knock yourself out I'd say.