Have been struggling with some issues with carting service. Have been trying to integrate and replace just the value from product to become item. ProductID to itemNo..

Error Code: Trying to get property of non-object.

CartController.php

<?php
 
namespace App\Http\Controllers;
use App\Cart;
use App\CartItem;
use Illuminate\Support\Facades\Auth;
 
use Illuminate\Http\Request;
 
use App\Http\Requests;
use App\Http\Controllers\Controller;
 
class CartController extends Controller
{
 
    public function __construct()
    {
        $this->middleware('auth');
    }
 
    public function addItem ($item){
 
        $cart = Cart::where('user_id',Auth::user()->id)->first();
 
        if(!$cart){
            $cart =  new Cart();
            $cart->user_id=Auth::user()->id;
            $cart->save();
        }
 
        $cartItem  = new Cartitem();
        $cartItem->itemNo=$itemNo;
        $cartItem->cart_id= $cart->id;
        $cartItem->save();
 
        return redirect('/cart');
 
    }
 
    public function showCart(){
        $cart = Cart::where('user_id',Auth::user()->id)->first();
 
        if(!$cart){
            $cart =  new Cart();
            $cart->user_id=Auth::user()->id;
            $cart->save();
        }
 
        $items = $cart->cartItems;
        $total=0;
        foreach($items as $item){
            $total+=$item->item->price;
        }
 
        return view('cart.view',['items'=>$items,'total'=>$total]);
    }
 
    public function removeItem($id){
 
        CartItem::destroy($id);
        return redirect('/cart');
    }
 
}
 

Cart/view.blade.php

@extends('layouts.default')

@section('iMakan', 'Cart')

@section('content')

    <div class="row">
        <div class="col-sm-12 col-md-10 col-md-offset-1">
            <table class="table table-hover">
                <thead>
                <tr>
                    <th>Item</th>
                    <th></th>
                    <th class="text-center"></th>
                    <th class="text-center">Total</th>
                    <th> </th>
                </tr>
                </thead>
                <tbody>
                @foreach($items as $item)
                    <tr>
                        <td class="col-sm-8 col-md-6">
                            <div class="media">
                                <a class="thumbnail pull-left" href="#"> <img class="media-object" src="{{$item->item->imageurl}}" style=" "> </a>
                                <div class="media-body">
                                    <h4 class="media-heading"><a href="#">{{$item->item->name}}</a></h4>
                                </div>
                            </div></td>
                        <td class="col-sm-1 col-md-1" style="text-align: center">
                        </td>
                        <td class="col-sm-1 col-md-1 text-center"></td>
                        <td class="col-sm-1 col-md-1 text-center"><strong>${{$item->item->price}}</strong></td>
                        <td class="col-sm-1 col-md-1">
                            <a href="/removeItem/{{$item->id}}"> <button type="button" class="btn btn-danger">
                                    <span class="fa fa-remove"></span> Remove
                                </button>
                            </a>
                        </td>
                    </tr>
                @endforeach

                <tr>
                    <td>   </td>
                    <td>   </td>
                    <td>   </td>
                    <td><h3>Total</h3></td>
                    <td class="text-right"><h3><strong>${{$total}}</strong></h3></td>
                </tr>
                <tr>
                    <td>   </td>
                    <td>   </td>
                    <td>   </td>
                    <td>
                        <a href="/"> <button type="button" class="btn btn-default">
                                <span class="fa fa-shopping-cart"></span> Continue Shopping
                            </button>
                        </a></td>
                    <td>
                        <button type="button" class="btn btn-success">
                            Checkout <span class="fa fa-play"></span>
                        </button></td>
                </tr>
                </tbody>
            </table>
        </div>
    </div>

@endsection

Refered: https://www.codetutorial.io/the-shopping-cart-how-to-craft-an-e-shop-with-laravel/