Django的inlineformset - 自定义的保存方法

Question

这是我的models.py

class Invoices(models.Model): 
    ... 
    sum_w_vat = models.DecimalField(max_digits=7, decimal_places=2, default=0) 
    sum_wo_vat = models.DecimalField(max_digits=7, decimal_places=2, default=0) 
    sum_discount = models.DecimalField(max_digits=7, decimal_places=2, default=0) 
    sum_vat = models.DecimalField(max_digits=7, decimal_places=2, default=0) 
    sum_paid = models.DecimalField(max_digits=7, decimal_places=2, default=0) 
    ... 

class InvoiceItems(models.Model): 
    invoice = models.ForeignKey(Invoices) 
    quantity = models.DecimalField(max_digits=9, decimal_places=2) 
    unit = models.ForeignKey(StocklistUnits, verbose_name='Merska enota') 
    price = models.DecimalField(max_digits=9, decimal_places=2) 
    vat = models.DecimalField(max_digits=4, decimal_places=3) 
    discount = models.DecimalField(max_digits=3, decimal_places=1) 
    def save(self, **kwargs): 
     self.invoice.sum_w_vat += (self.price * self.quantity * self.vat) * self.discount 
     self.invoice.sum_wo_vat += (self.price * self.quantity) * self.discount 
     self.invoice.sum_discount += (self.price * self.quantity) * (self.discount/100) 
     self.invoice.sum_vat += ((self.price * self.quantity * self.vat) * self.discount) - ((self.price * self.quantity) * self.discount) 
     super(InvoicesItems, self).save(**kwargs) 

我不知道如何保存在重新保存功能的InvoiceItems计算数据......这显然是行不通的，因为Invoices先被保存...

views.py

def edit(request, id = None): 
InvoiceFormSet = inlineformset_factory(Invoices, InvoicesItems) 

if id == None: 
    initial_data = '' 
    data = Invoices() 
else: 
    data = get_object_or_404(Invoices, pk=id) 
    initial_data = '' 

if request.method == 'POST': 
    created_invoice = InvoicesForm(request.POST, instance=data) 

    form = InvoiceFormSet(request.POST, instance=data) 

    if not form.is_valid() and not created_invoice.is_valid(): 
     //json err msg 
    else: 
     created_invoice.save() 
     form.save() 


    json = simplejson.dumps(response, ensure_ascii=False) 
    return HttpResponse(json, mimetype="application/json") 
else: 
    form = InvoicesForm(instance=data, initial=initial_data) 
    form_items = InvoiceFormSet(instance=data) 
    c = {'form':form, 'form_items':form_items} 
    c.update(csrf(request)) 
    return render_to_response('crud_invoice_edit.html', c) 

我如何通过InvoiceItems迭代和计算字段，则需要被插入Invoices。我是django的新手...

谢谢！

Answer 1

我不知道这是正确的方式...但它的工作原理...

我所要做的就是再次保存created_invoice ......所以

created_invoice.save() 
form.save() 
created_invoice.save()