Laravel 5 add attribute to User model before login

I need to add a custom attribute to the User model when the user logs in. This value is not in the database so needs to be added after.

The attribute I need to add is called client_id

I've search everywhere for a solution but everything I've tried doesn't work. When I dump out the user in another controller, I don't see the attribute I added.

I've stripped out everything that I tried and I'm left with the original model.

Here is my User model

<?php

namespace App;

use Illuminate\Notifications\Notifiable;
use Illuminate\Contracts\Auth\MustVerifyEmail;
use Illuminate\Foundation\Auth\User as Authenticatable;

class User extends Authenticatable
{
    use Notifiable;

    protected $connection = 'mysql';

    /**
     * The database table used by the model.
     *
     * @var string
     */
    protected $table = 'users';

    /**
     * The attributes that are mass assignable.
     *
     * @var array
     */
    protected $fillable = ['username'];

    /**
     * The attributes that should be hidden for arrays.
     *
     * @var array
     */
    protected $hidden = [
        'password',
    ];
}

And here is my LoginContorller

<?php

namespace App\Http\Controllers\Auth;

use App\Http\Controllers\Controller;
use Illuminate\Foundation\Auth\AuthenticatesUsers;
use Illuminate\Http\Request;
use \DB;
// Models
use App\User;

class LoginController extends Controller
{
    /*
    |--------------------------------------------------------------------------
    | Login Controller
    |--------------------------------------------------------------------------
    |
    | This controller handles authenticating users for the application and
    | redirecting them to your home screen. The controller uses a trait
    | to conveniently provide its functionality to your applications.
    |
    */

    use AuthenticatesUsers;

    /**
     * Where to redirect users after login.
     *
     * @var string
     */
    protected $redirectTo = '/home';

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

     public function login(Request $request)
     {
         // Check validation
         $this->validate($request, [
             'username' => 'required|regex:/^([a-z0-9-_\.]+)*@([a-z0-9-]+)$/',
             'password' => 'required'
         ]);

        $user = User::where('username', $request->input('username'))
            ->where('isActive', 1)
            ->first();

        // Set Auth Details
        \Auth::login($user);

        // Redirect home page
        return redirect()->route('dashboard');
    }
}

I tied adding an attribute using $user->setAtttribute('client_id', 12345); before \Auth::login($user); but it didn't work

via Chebli Mohamed