JsonResponse by default expect to return a Json Dict. Using: safe=False you override this behavior telling that it’s OK to return a non dict object.

Your problem is that in this line:

    return response.json()

Your JS code wait as well for a dict.

So you have to pass a JsonDict in the response and JS will be able to parse it

I have a simple add and remove button for a cart, but whenever i click on the button, i get an error in the console, please bear in mind, i a newbie:

cart.js:25 POST http://127.0.0.1:8000/update_item/ 404 (Not Found)
updateUserOrder @ cart.js:25
(anonymous) @ cart.js:14
127.0.0.1/:1 Uncaught (in promise) SyntaxError: Unexpected token < in JSON at position 0

And this is the error i get in my terminal:

Not Found: /update_item/

I strongly feel this is the problem, as the fetch is not recognizing update_item in views.py

This is the code in cart.js:

function updateOrder (ticketId, action){
console.log('User is logged in, sending data..')

var url = '/update_item/'

fetch(url, {
    method:'POST',
    headers:{
        'Content-Type':'application/json',
        'X-CSRFToken': csrftoken,
    },
    body:JSON.stringify({'ticketId': ticketId, 'action':action})
})

.then((response) =>{
    return response.json()
})
.then((data) =>{
    console.log('data:', data)
    location.reload()
})

}

This is my views.py code:

def updateItem(request):
data = json.loads(request.body)
ticketId = data['ticketId']
action = data['action']

print('Action:', action)
print('ticketId:', ticketId)


customer = request.user.customer
ticket = Ticket.objects.get(id=ticketId)
order, created = Order.objects.get_or_create(customer=customer, complete=False)

orderItem, created = OrderItem.objects.get_or_create(order=order, ticket=ticket)

if action == 'add':
    orderItem.quantity = (orderItem.quantity + 1)
elif action == 'remove':
    orderItem.quantity = (orderItem.quantity - 1)

orderItem.save()

if orderItem.quantity <= 0:
    orderItem.delete()

return JsonResponse('Item was added', safe=False)