Update Price and Qty by also checking product Qty in the product Table

Certainly! Here’s a step-by-step solution for your requirements using Laravel, Livewire, and the bumbummen99/shoppingcart package.

1. Livewire Component Setup

Assume you have a Livewire component called InvoiceCart.

Properties

public $cartContents = [];
public $vatPercentage = 0;
public $advancePayment = 0;
public $subtotal = 0;
public $vatAmount = 0;
public $totalAmount = 0;
public $balance = 0;
public $errors = [];

Mount Method

public function mount()
{
    $this->cartContents = \Cart::content()->toArray();
    $this->calculateTotals();
}

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2. Update Cart Item (Qty & Price) and Check Product Stock

public function updateCartItem($rowId, $qty, $price)
{
    $cartItem = \Cart::get($rowId);
    $product = \App\Models\Product::find($cartItem->id);

    // Check stock
    if ($qty > $product->qty) {
        $this->errors[$rowId] = "Requested quantity exceeds available stock ({$product->qty}).";
        return;
    } else {
        unset($this->errors[$rowId]);
    }

    // Update cart
    \Cart::update($rowId, [
        'qty' => $qty,
        'price' => $price,
    ]);

    $this->cartContents = \Cart::content()->toArray();
    $this->calculateTotals();
}

---

3. Calculate Subtotal, VAT, Total, and Balance

public function calculateTotals()
{
    $this->subtotal = \Cart::subtotal(2, '.', '');
    $this->vatAmount = ($this->vatPercentage / 100) * $this->subtotal;
    $this->totalAmount = $this->subtotal + $this->vatAmount;
    $this->balance = $this->totalAmount - $this->advancePayment;
}

---

4. Update VAT or Advance Payment

public function updatedVatPercentage()
{
    $this->calculateTotals();
}

public function updatedAdvancePayment()
{
    $this->calculateTotals();
}

---

5. Blade Example

@foreach($cartContents as $rowId => $item)
    <div>
        <input type="number" wire:model.lazy="cartContents.{{ $rowId }}.qty" 
               wire:change="updateCartItem('{{ $rowId }}', {{ $item['qty'] }}, {{ $item['price'] }})">
        <input type="number" wire:model.lazy="cartContents.{{ $rowId }}.price" 
               wire:change="updateCartItem('{{ $rowId }}', {{ $item['qty'] }}, {{ $item['price'] }})">
        @if(isset($errors[$rowId]))
            <span class="text-danger">{{ $errors[$rowId] }}</span>
        @endif
    </div>
@endforeach

<div>
    Subtotal: {{ $subtotal }}
    <input type="number" wire:model="vatPercentage"> VAT (%)
    <br>
    VAT Amount: {{ $vatAmount }}
    <br>
    Total: {{ $totalAmount }}
    <br>
    Advance Payment: <input type="number" wire:model="advancePayment">
    <br>
    Balance: {{ $balance }}
</div>

---

6. Notes

• Make sure to call calculateTotals() after any cart update.
• The error message is shown only for the product that exceeds stock.
• You can further improve UX by debouncing input or adding validation rules.

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Let me know if you need more details or a full component code!