Laravel-5.7：未定义变量：购物车

Question

我正在尝试将产品添加到购物车，当我单击添加到购物车然后将其保存到购物车后它必须重定向到购物车页面，产品正在添加到购物车（保存到 db 购物车表）但购物车页面显示：未定义变量：购物车 (View:D:\xampp\htdocs\laravel\ecom2\resources\views\products\cart.blade.php）

ProductsController代码：

  public function addtocart(Request $request){
  $data = $request->all();
  //echo "<pre>"; print_r($data); die;

  if(empty($data['user_email'])){
    $data['user_email'] = '';
  }


  $session_id = Session::get('session_id');
  if(empty($session_id)){
      $session_id = str_random(40);
      Session::put('session_id',$session_id);
  }


  DB::table('cart')->insert(['product_id'=>$data['product_id'],'product_name'=>$data['product_name'],'product_code'=>$data['product_code'],'product_color'=>$data['product_color'],'price'=>$data['price'],'size'=>$data['size'],'quantity'=>$data['quantity'],'user_email'=>$data['user_email'],'session_id'=>$session_id]);

  return redirect('cart')->with('flash_message_success','Product has been added in Cart!');
}

public function cart(){
  $session_id = Session::get('session_id');
  $userCart = DB::table('cart')->where(['session_id'=>$session_id])->get();
  foreach ($userCart as $key => $product) {
    $productDetails = Product::where('id',$product->product_id)->first();
    $userCart[$key]->image = $productDetails->image;
  }
  return view('products.cart')->with(compact('userCart'));
}

cart.blade.php：

  @extends('layouts.frontLayout.front_design')
  @section('content')

 <!-- Cart -->
 <section class="cart bgwhite p-t-70 p-b-100">
    <div class="container">
        <!-- Cart item -->
        <div class="container-table-cart pos-relative">
            <div class="wrap-table-shopping-cart bgwhite">
                <table class="table-shopping-cart">
                    <tr class="table-head">
                        <th class="column-1"></th>
                        <th class="column-2">Product</th>
                        <th class="column-3">Price</th>
                        <th class="column-4 p-l-70">Quantity</th>
                        <th class="column-5">Total</th>
                    </tr>

                    <tr class="table-row">
                        <td class="column-1">
                            <div class="cart-img-product b-rad-4 o-f-hidden">
                                <img src="{{ 
    asset('images/backend_images/products/small/'.$cart->image) }}" alt="IMG- 
     PRODUCT">
                            </div>
                        </td>
                        @foreach($userCart as $cart)
                        <td class="column-2">{{ $cart->product_name }}</td>
                        <td class="column-3">PKR: {{ $cart->price }}</td>
                        <td class="column-4">
                            <div class="flex-w bo5 of-hidden w-size17">
                                <button class="btn-num-product-down color1 flex-c-m size7 bg8 eff2">
                                    <i class="fs-12 fa fa-minus" aria-hidden="true"></i>
                                </button>

                                <input class="size8 m-text18 t-center num-product" type="number" name="quantity" value="{{ $cart->price }}">

                                <button class="btn-num-product-up color1 flex-c-m size7 bg8 eff2">
                                    <i class="fs-12 fa fa-plus" aria-hidden="true"></i>
                                </button>
                            </div>
                        </td>
                        <td class="column-5">PKR: {{ $cart->price*$cart->quantity }}</td>
                    </tr>
                        @endforeach
                </table>
            </div>
        </div>

        <div class="flex-w flex-sb-m p-t-25 p-b-25 bo8 p-l-35 p-r-60 p-lr-15-sm">
            <div class="flex-w flex-m w-full-sm">
                <div class="size11 bo4 m-r-10">
                    <input class="sizefull s-text7 p-l-22 p-r-22" type="text" name="coupon-code" placeholder="Coupon Code">
                </div>

                <div class="size12 trans-0-4 m-t-10 m-b-10 m-r-10">
                    <!-- Button -->
                    <button class="flex-c-m sizefull bg1 bo-rad-23 hov1 s-text1 trans-0-4">
                        Apply coupon
                    </button>
                </div>
            </div>

            <div class="size10 trans-0-4 m-t-10 m-b-10">
                <!-- Button -->
                <button class="flex-c-m sizefull bg1 bo-rad-23 hov1 s-text1 trans-0-4">
                    Update Cart
                </button>
            </div>
        </div>

        <!-- Total -->
        <div class="bo9 w-size18 p-l-40 p-r-40 p-t-30 p-b-38 m-t-30 m-r-0 m-l-auto p-lr-15-sm">
            <h5 class="m-text20 p-b-24">
                Cart Totals
            </h5>

            <!--  -->
            <div class="flex-w flex-sb-m p-b-12">
                <span class="s-text18 w-size19 w-full-sm">
                    Subtotal:
                </span>

                <span class="m-text21 w-size20 w-full-sm">
                    $39.00
                </span>
            </div>

            <!--  -->
            <div class="flex-w flex-sb bo10 p-t-15 p-b-20">
                <span class="s-text18 w-size19 w-full-sm">
                    Shipping:
                </span>

                <div class="w-size20 w-full-sm">
                    <p class="s-text8 p-b-23">
                        There are no shipping methods available. Please double check your address, or contact us if you need any help.
                    </p>

                    <span class="s-text19">
                        Calculate Shipping
                    </span>

                    <div class="rs2-select2 rs3-select2 rs4-select2 bo4 of-hidden w-size21 m-t-8 m-b-12">
                        <select class="selection-2" name="country">
                            <option>Select a country...</option>
                            <option>US</option>
                            <option>UK</option>
                            <option>Japan</option>
                        </select>
                    </div>

                    <div class="size13 bo4 m-b-12">
                    <input class="sizefull s-text7 p-l-15 p-r-15" type="text" name="state" placeholder="State /  country">
                    </div>

                    <div class="size13 bo4 m-b-22">
                        <input class="sizefull s-text7 p-l-15 p-r-15" type="text" name="postcode" placeholder="Postcode / Zip">
                    </div>

                    <div class="size14 trans-0-4 m-b-10">
                        <!-- Button -->
                        <button class="flex-c-m sizefull bg1 bo-rad-23 hov1 s-text1 trans-0-4">
                            Update Totals
                        </button>
                    </div>
                </div>
            </div>

            <!--  -->
            <div class="flex-w flex-sb-m p-t-26 p-b-30">
                <span class="m-text22 w-size19 w-full-sm">
                    Total:
                </span>

                  <span class="m-text21 w-size20 w-full-sm">
                    $39.00
                  </span>
              </div>

              <div class="size15 trans-0-4">
                <!-- Button -->
                <button class="flex-c-m sizefull bg1 bo-rad-23 hov1 s-text1 trans-0-4">
                    Proceed to Checkout
                </button>
            </div>
          </div>
       </div>
    </section>

   @endsection

Answer 1

这也可能是您在页面的其他地方使用了 $cart 变量的情况。如果您提供整个 cart.blade.php 会很有帮助，因为您的 @foreach 也不完全正确，您已经在结束标记之前结束了循环，并且在开始之前没有打开循环......

    @foreach($userCart as $cart)
     <tr>
      //your other elements consisting of $cart
     </tr>
    @endforeach

Answer 2

我相信如果您将购物车功能更改为以下内容，它将起作用。

public function cart(){
  $session_id = Session::get('session_id');
  $userCart = DB::table('cart')->where('session_id', $session_id)->get();
  foreach ($userCart as $key => $product) {
    $productDetails = Product::find($product->product_id);
    $product->image = $productDetails->image;
  }
  return view('products.cart', compact('userCart'));
}

Answer 3

检查您的会话是否为空，并在不在控制器中的模型中进行查询 “面向对象编程 laravel”。