Handle object in class helper - Best practice

I made this class for categories:

PHP Code:

class Categories
{

    private $_category;
    private $_ci;

    public function __construct($category){

        $this->_ci = get_instance();
        $this->_ci->load->model('produse_model', 'produse');
        $this->_category = $category;
    }


    public function categories(){

        foreach($this->_category as $categorie):
            $categorie->numar_produse = $this->_ci->produse->count_by_category_id($categorie->id_categorie);
        endforeach;

        return $this->_category;
    }

    public function category(){

        return $this->_category->numar_produse = $this->_ci->produse->count_by_category_id($this->_category->id_categorie);
    }

} 


Then in controller:

PHP Code:

$categories         = new Categories($this->categorii->entries());
$data["categories"] = $categories->categories(); 


So in my class I get the number of the items for each category.



Is this the best practice?

Why not transform it into a library?

Website: http://avenir.ro

Why not transform it into a library?

Can you tell me the difference?

Advantages?

i'm not so sure about your way of doing things
i think in general you should avoid calling models within your objects because objects needs to get filled by a model
and the model should return the prepared objects to the controller

a Library can do that but in this case i think a library is a wrong approach - you need a category wrapper object or something like this

Like you told me in this post http://forum.codeigniter.com/thread-63496.html ?

exactly

I was thinking, wouldn't be more practice if I join the categories table with products and count the products? And no more foreach and count method needed.


EDIT
This was the best solution:

PHP Code:

function entries() {
        $this->db->select('a.nume_categorie, a.slug_categorie, COUNT(a.id_categorie) as numar_produse');
        $this->db->from($this->_table.' a');
        $this->db->join('produse b', 'a.id_categorie = b.id_categorie');
        $this->db->group_by('a.id_categorie');
        $result = $this->db->get();
        //echo $this->db->last_query();
        return $result->result();
    } 


Or I can use query cache, and on every ADD/DELETE delete cache and rebuild.