How to get different user info when logged in.

It depends on what you are returning from your slug method an object or an associate array.

You need to show your get_by_slug method in your model.

I'm returning an object using $query->row(). Should I change it to result_array()?

PHP Code:

   public function get_by_slug($slug)
    {
        $this->db->select('*');
        $this->db->from($this->table);
        $this->db->where('slug', $slug);
        $this->db->where('is_published', 1);
        $this->db->limit(1);

        $query = $this->db->get();

        if ($query->num_rows() == 1) {
            return $query->row();
        } else {
            return false;
        }
    } 


But would it be possible to return value from a different table(users) ?

I do Front-End development most of the time