Objects within objects?

[effovex]

All hail!
I've been trying to create an object-oriented Forum using PHP. My basic logic is that a forum is an object which contains objects for users, messages and such elements.

My problem is that I can't seem to us the methods to those objects within the forum object.

For exemple, there is a member variable named $user in the forum class. $user is set to represent the currently logged in user. I set this variable to a new User object in the constructor.

The problem is when I try to access $user's method later on, using $this->user->method(), I get an error (depending on the context, the error differs, for exemple if used in an if() statement the parser expects a closing parenthesis after $this->user)

I have tried using
$user = $this->user;
$user->method();

and

$user &= $this->user;
$user->method();

but neither work (and I really don't understand why). I'm thinking maybe it would work using call_user_func(), but I'm not quite sure how I should proceed.

(Oh, yeah, I'm using PHP 4.2)

[sarahk]

You can do this but the better practice would be to have a method called setUserName

so you would call
$obj->setUserName("fred");

and the setUserName would look like

function setUserName($uname)
{
  $u =  $this->user;
  $u->name = $uname;
}

However what you are trying to do can be done, I just don't recall the syntax.

There is also a school of thought that only the object should ever set it's properties so in the example above instead of $u->name = $uname I should have had $u->setName($uname);

[matto]

hi!

as for oo style, sarahk is right.
however, your approach should work, too!

here's an example where both accessing methods work (tested with php 4.0.4 pl1 and 4.2.3):

<?

class User
{
        var $name;

    function User()
    {
    }

    function setName($astring)
    {
            $this->name = $astring;
    }

    function getName()
    {
            return $this->name;
    }
}

class UserArray
{
        var $users;

    function UserArray()
    {
            $this->users = array();
    }

    function addUser($anobject)
    {
            $this->users[] = $anobject;
    }

    function getUsers()
    {
            return $this->users;
    }
}

// testing -------------

$ua = new UserArray();
$u = new User();
$u->setName("Paul");
$ua->addUser($u);

echo "directly accessing user in userarray<br>";
echo $ua->users[0]->getName()."<br><br>";

echo "indirect access (better oo style)<br>";
$users = $ua->getUsers();
$user = $users[0];
echo $user->getName();

?>

output is:

directly accessing user in userarray
Paul

indirect access (better oo style)
Paul

[effovex]

Yeah for the OO style, my actual program doesn't look anything like that. I was trying to give enough context so that you guys would understand what I'm doing, but removing unnecessary details so that it wasn't overly complex.

Anyway, I've got it to work. It was stupid mistake actually :o. I was using empty() to check for the method's return value, which apparently is illegal. What confused my is that I could make it work by removing the method at the end, making me think I couldn't access objects within objects while it was the method itself that was the problem.

Not sure if I'm making sense. Anyway, thanks a lot 🙂