Hello, I am trying to inject an attribute on my construtor to avoid to redeclare it on every method so this is my method but's when I am not logged, it fail with Fatal error Non object...

class ModController extends Controller {

private $blog;

/**
 * Create a new controller instance.
 *
 * @return void
 */
public function __construct()
{
    $this->middleware('auth');

    $this->blog= Auth::user()->blogs()->first(); //this work only when I am logged
}

public function dashboard()
{
    // here I want to avoid to make on every method this line
    // $blog =  Auth::user()->blogs()->first();
    return view('panel.dashboard', ['blog' => $this->blog]);
}