Question

I need to use $GLOBALS['db'] in my classes ($db is defined in my index.php), but I don’t want to use $GLOBALS['db'] when I have to call it.

I wrote this code at the beginning of my classes :

class ClassName
{
    var $db;

    public function __construct()
    {
        $this->db = $GLOBALS['db'];
    }

    public function test()
    {
        $val = $this->db->oneValue('SELECT first_name FROM users LIMIT 0, 1');
        echo $val->first_name;
    }
}

But I’m not enjoying this; I prefer to use directly $db in my code. Is there a solution to be able to call $GLOBALS['db'] by $db?

Answer 1

Simples, just inject in the constructor or a setter method: (I’m assuming $db is an object here, not an array of connection parameters etc)

class ClassName
   {
   protected $db;

   public function __construct($db)
   {
       $this->setConnection($db);
       //Any other constructor things you want to happen...
   }

   /*
    * This is just here for convenience, this could be protected if you only want to set 
    * the db connection via the constructor
    */
   public function setConnection($db)
   {
       $this->db = $db;
   }    

   public function test()
   {
       $val = $this->db->oneValue('SELECT first_name FROM users LIMIT 0, 1');
       echo $val->first_name;
   }
}

As mentioned in some comments above, this is a form of dependency injection which will give you more ability to re-use code inside your project (A Good Thing TM).