Reduce stock number in laravel - laravel

Question

How can I reduce the number of stock in laravel?
In my products table i have stock column where i set numbers of item i have and i want to reduce it in 2 conditions:
1- when is added to order table (not when the product is in user cart)
2- when the order status is not cancelled (if order status become cancelled stocks increase back)
PS: currently I have no code for this matter that's why i didn't share
any code, I'm seeking for idea of how done it. Base on that i will
make functions and share here to complete it.
JSON of Order
"[{\"id\":29,\"name\":\"effewf\",\"price\":24524,\"quantity\‌​":1,\"attributes\":[‌​{\"attr\":{\"label\"‌​:\"Gray\",\"price\":‌​\"7000.00\"}}],\"con‌​ditions\":[]},{\"id\‌​":27,\"name\":\"new product\",\"price\":7246,\"quantity\":2,\"attributes\":[],\"‌​conditions\":[]}]"
UPDATE
base on #btl answer I added code below in my order model:
protected static function boot()
{
parent::boot();
$productIdsAndQuantities = $this->products->map(function ($product) {
return [$product->id => $product->quantity];
});
static::updating(function (Order $order) {
// restock if cancelled
$oldStatus = OrderStatus::find($order->getOriginal('orderstatus_id'));
if ($oldStatus->title !== 'Cancelled' && $order->orderstatus->title === 'Cancelled') {
$order->products->each(function(Product $product) {
$stock = $product->getAttribute('stock');
$product->update([
'stock' => $stock + $product->order->getAttribute($productIdsAndQuantities)
]);
});
}
});
}
I think this code needs fix in $productIdsAndQuantities and $product->update(['stock' => $stock + $product->order->getAttribute($productIdsAndQuantities)]); parts before i can use it.
currently i get error below when i try to add my cart detail to orders table
Using $this when not in object context
UPDATE 2
I changed my code to:
protected static function boot()
{
parent::boot();
static::updating(function (Order $order) {
$productIdsAndQuantities = $order->product_name->map(function ($product) {
return [$product->id => $product->quantity];
});
// restock if cancelled
$oldStatus = OrderStatus::find($order->getOriginal('orderstatus_id'));
if ($oldStatus->title !== 'Cancelled' && $order->orderstatus->title === 'Cancelled') {
$order->products->each(function(Product $product) {
$stock = $product->getAttribute('stock');
$product->update([
'stock' => $stock + $product->order->getAttribute($productIdsAndQuantities)
]);
});
}
});
}
now my order will be placed but nothing changes on stock column.
any idea?

Answer 1

Your tables look like,
Product
Schema::create('products', function (Blueprint $table) {
$table->increments('id');
$table->string('name');
......
$table->integer('stock');
$table->timestamps();
});
Stock
Schema::create('stocks', function (Blueprint $table) {
$table->increments('id');
$table->integer('product_id')->unsigned();
$table->integer('order_id')->unsigned();
$table->enum('fall_rise',[-1,1]);
$table->timestamps();
$table->foreign('product_id')->references('id')->on('products');
$table->foreign('order_id')->references('id')->on('orders');
});
orders
Schema::create('orders', function (Blueprint $table) {
$table->increments('id');
.....
.....
$table->timestamps();
});
Now, add a sample product with stock value 10 like
$product = new Product();
$product->name = "abc";
......
$product->stock = 10;
$product->save();
Now, when abc is ordered, add details in order table. Now, stock value to be decreased then update value of stock column in product by 10-1 = 9, add record in stocks table like
Sample values,
product_id = 1;
order_id = 1;
....
fall_rise = -1;
In this way, when 10 stocks of the product are ordered then stock column becomes zero and hence product becomes unavailable. If you want to fetch only available products then use query like,
$available_products = Product::where('stock', '>', 0)->get();
I hope you will understand.

Answer 2

Register model events to handle updates on orders.
In your Order model:
protected static function boot()
{
parent::boot();
static::updating(function (Order $order) {
// restock if cancelled
$oldStatus = OrderStatus::find($order->getOriginal('orderstatus_id');
if ($oldStatus->name !== 'cancelled' && $order->orderstatus->name === 'cancelled') {
$order->products->each(function(Product $product) {
$stock = $product->getAttribute('stock');
$product->update(['stock' => $stock + $product->order->getAttribute('quantity_of_product_ordered')]);
});
}
// added to order table similar to above...
// check if it's a new product id being added to the order, decrease stock quantity accordingly...
// ...
});
}

Answer 3

SOLVED
the trick was to use try { on my CartController when I wanted to save my data in orders table there I should place my codes like:
try {
$order = new Order();
$qty = Cart::getTotalQuantity();
$order->product_data = $cartItems;
$order->user_id = Auth::user()->id;
// rest of it...
Auth::user()->orders()->save($order);
//trick is in this part
foreach ($cartItems as $item) {
$product = Product::find($item->id);
$product->decrement('stock', $item->quantity);
}
the answer was provided here