试图在Laravel 5中获得非对象的属性

Question

I'm getting the

ErrorException: Trying to get property of non-object

I'm trying to display all the relationship that is link using this function. The relationship is ->

-Card can have many notes, Notes only have one card. -Each notes contain only one user, User contain only one card. My code is:

Model

1. Note

   class Note extends Model
   {
   protected $fillable = ['body'];
   
       public function cards()
       {
           return $this->belongsTo(Card::class);
       }
   
       public function users()
       {
           return $this->belongsTo(User::class,'id');
       }
   
   }
   

2. User

   class User extends Authenticatable
   {
       use Notifiable;
   
       public function note()
       {
           return $this->belongsTo(Note::class);
       }
   
       protected $fillable = [
           'name', 'email', 'password',
       ];
   
       protected $hidden = [
           'password', 'remember_token',
       ];
   }
   

3. Card

   class Card extends Model
   {
        public function notes()
       {
           return $this->hasMany(Note::class);//relationship
       }
   
       public function addNote(Note $note)
       {
           return $this->notes()->save($note);
       }
   }
   

Controller

1. CardsController

   class cardsController extends Controller
   {
       public function index()
       {
           $cards = Card::all();
           return view('cards.index',compact('cards'));
       }
   
   public function show(Card $card)
   {
       $card->load('notes.user'); **The Error is here.**
       $return $card;
       return view('cards.show',compact('card'));
   }
   

   }

2. NotesController

   class notesController extends Controller
   {
   
       public function store(Request $request, Card $card)
       {
           $card->addNote(
                   new Note($request->all())
               ); 
   
           return back();
      }
   
       public function edit(Note $note)
       {
           return view('notes.edit',compact('note'));
       }
   
       public function update(Request $request, Note $note)
       {
           $note -> update($request -> all());
   
           return back();
       }
   }
   

DB

1. notes table

$card->load('notes.user'); -when I just put (notes) in the cardControllers function, it will appear all data that link from card and notes table. -but when I try to add (notes.user) it said that trying to get non property object. Am I missing something?

Answer 1

This is a very common and self explanatory error, it comes when you are trying to access a class property which doesn't really exist.

To avoid this, use isset() before access the property.