Updating Database Field with AJAX Laravel - php

Question

I am trying to update my stock level by subtracting the cart item quantity from the product quantity in the database when a user completes an order using the POST method. Everytime I run the method the success function occurs but the field doesnt update doesnt update.
Could anyone tell me why?
My Controller:
public function index ()
{
$products = Product::all();
return view('products', compact('products'));
}
public function cart()
{
return view('cart');
}
public function addToCart($id)
{
$product = Product::find($id);
if(!$product) {
abort(404);
}
$cart = session()->get('cart');
// if cart is empty then this will be the first product
if(!$cart) {
$cart = [
$id => [
"name" => $product->name,
"quantity" => 1,
"price" => $product->unit_price
]
];
session()->put('cart', $cart);
return redirect()->back()->with('success', 'Product added to cart successfully!');
}
// if cart isnt empty then check if this product exist then increment quantity
if(isset($cart[$id])) {
$cart[$id]['quantity']++;
session()->put('cart', $cart);
return redirect()->back()->with('success', 'Product added to cart successfully!');
}
// if item doesnt exist in cart then add to cart with quantity = 1
$cart[$id] = [
"name" => $product->name,
"quantity" => 1,
"price" => $product->unit_price
];
session()->put('cart', $cart);
return redirect()->back()->with('success', 'Product added to cart successfully!');
}
public function update(Request $request)
{
if($request->id and $request->quantity)
{
$cart = session()->get('cart');
$cart[$request->id]["quantity"] = $request->quantity;
session()->put('cart', $cart);
session()->flash('success', 'Cart updated successfully');
}
}
public function remove(Request $request)
{
if($request->id) {
$cart = session()->get('cart');
if(isset($cart[$request->id])) {
unset($cart[$request->id]);
session()->put('cart', $cart);
}
session()->flash('success', 'Product removed successfully');
}
}
public function stock (Request $request)
{
if($request->id and $request->quantity)
{
$cart = session()->get('cart');
$cart[$request->id]['quantity'] = $request->quantity;
$products = Product::all();
$stock = $products->unit_stock;
$quantity = $stock - $cart;
return $quantity;
}
}
My Route:
Route::post('stock', 'ProductController#stock');
My view cart.blade.php:
#extends('layout')
#section('content')
<table id="cart" class="table table-hover table-condensed">
<thead>
<tr>
<th style="width:50%">Product</th>
<th style="width:10%">Price</th>
<th style="width:8%">Quantity</th>
<th style="width:22%" class="text-center">Subtotal</th>
<th style="width:10%"></th>
</tr>
</thead>
<tbody>
<?php $total = 0 ?>
#if(session('cart'))
#foreach(session('cart') as $id => $details)
<?php $total += $details['price'] * $details['quantity'] ?>
<tr>
<td data-th="Product">
<div class="row">
<div class="col-sm-9">
<h4 class="nomargin">{{ $details['name'] }}</h4>
</div>
</div>
</td>
<td data-th="Price">${{ $details['price'] }}</td>
<td data-th="Quantity">
<input type="number" value="{{ $details['quantity'] }}" class="form-control quantity" />
</td>
<td data-th="Subtotal" class="text-center">${{ $details['price'] * $details['quantity'] }}</td>
<td class="actions" data-th="">
<button class="btn btn-info btn-sm update-cart" data-id="{{ $id }}"><i class="fa fa-refresh"></i></button>
<button class="btn btn-danger btn-sm remove-from-cart" data-id="{{ $id }}"><i class="fa fa-trash-o"></i></button>
</td>
</tr>
#endforeach
#endif
</tbody>
<tfoot>
<tr class="visible-xs">
<td class="text-center"><strong>Total {{ $total }}</strong></td>
</tr>
<tr>
<td><i class="fa fa-angle-left"></i> Continue Shopping</td>
<td colspan="2" class="hidden-xs"></td>
<td class="hidden-xs text-center"><strong>Total ${{ $total }}</strong></td>
</tr>
</tfoot>
<div class="row">
<div class="btn col-md-12">
Test
</div>
</div>
</table>
<script type="text/javascript">
$("#order-complete").click(function (e){
e.preventDefault();
var ele = $(this);
$.ajax({
url: '{{ url('stock') }}',
method: "post",
data: {_token: '{{ csrf_token() }}'},
success: function () {
window.location.reload();
}
});
});
</script>
#endsection

Answer 1

I can see a couple of potential issues that might be causing this. Firstly, it looks like you're trying to set stock against all of the products in your database in one go by loading a collection containing them all, rather than looping/loading the ones contained in the order ($request). You do this here;
$products = Product::all();
Then you try to change the stock for all products in the collection here;
$stock = $products->unit_stock;
$quantity = $stock - $cart;
I imagine you should have a collection of products in your $cart variable that you should loop over and load to manipulate. Some pseudo code to illustrate my point;
foreach($product in $cart){
$loadedProduct = Product::find($product);
$loadedProduct->stock = $loadedProduct->stock - $product["quantity"];
$loadedProduct->save();
}
You also aren't saving any products in the code you provided. There's an example of this in the pseudo code above.

Answer 2

I can spot a few mistakes from your code.
Lets focus on the function that the ajax request calls.
This line here tells me that there is a data id and quantity being sent.
if($request->id and $request->quantity)
From the look of your Route, it is in the body. But in the ajax function, you're didn't include any data except the csrf token. Try adding id and quantity data. This is just an assumption of the value.
data: {_token: '{{ csrf_token() }}', id: 6, quantity: 2},
Secondly, this function returns a collections of product.
$products = Product::all();
So if you would like to modify a product you must access its index. e.g.
$products[0]->unit_stock = 3;
$products[0]->save();
Or what Lewis has stated, you can use a foreach loop to iterate every object in the collection