Ok.
First of all you don't really need to get both. What you need to do is get
the PurchaseOrder connected to the url - then you get the items from the
purchase order.
So what I would do is the following:
First make sure that you hvae the right url definition, something like this
would work:
path('purchase_order/<int:pk>/',
views.PurchaseOrderDetailView.as_view(),
name='purchase-order-detail'),
Then use the DetailView from django to extend - this does a lot of magic
under the hood, and is much better to use.
class PurchaseOrderDetailView(LoginRequiredMixin, DetailView):
model = PurchaseOrder
template_name = 'financial/purchase_orders/purchase_order_detail.html'
def get_object(self, queryset=None):
return self.get_queryset().get(po_number=self.kwargs.get('pk'))
Now the reason for this is that you need to write a lot less code. Another
question is why you don't use the default id field on the purchase order?
Because if you did, you wouldn't need to add the get_object() method to the
detail view. Also if you follow the correct layout of your templates (in
this case it should be called purchaseorders/purchaseorder_defailt.html and
you don't need to add a template name either). Essentially the code for
your detail view could be only:
class PurchaseOrderDetailView(LoginRequiredMixin, DetailView):
model = PurchaseOrder
If you follow the guidelines that the detail view requires :-)
If you use my method here you will get the purchase order from the context
object: purchaseorder so your template would be able to access the
information in the purchase order by writing:
{{ purchaseorder.info }}
Then to get the items of the purchase order all you need to do is iterate
over them:
{% for item in purchaseorder.purchaseorderitem_set %}
{{ item.qty }}
{% endfor %}
You can look at the following tutorial that explains the usage of generic
class based views:
https://developer.mozilla.org/en-US/docs/Learn/Server-side/Django/Generic_views
I find woring WITH the framework is much easier than reinventing the wheel
:-)
Regards,
Andréas
2018-08-03 22:58 GMT+02:00 Alexander Joseph <alexander.v.jos...@gmail.com>:
> Thanks Andréas, very helpful!
> One more question -
> Since I'm using class based views and this view requires 2 models I'm
> unsure how to fetch the data from both the models to use in the same view.
> It looks like I need to modify the get_context_data() method but I'm unsure
> how to filter this way. Here is my view now
>
> class PurchaseOrderDetailView(LoginRequiredMixin, TemplateView):
> #context_object_name = "po"
> #model = PurchaseOrder
> template_name = 'financial/purchase_orders/purchase_order_detail.html'
>
> def get_context_data(self, **kwargs):
> context = super(PurchaseOrderDetailView, self).get_context_data(**
> kwargs)
> context['purchase_order'] = PurchaseOrder.objects.get()
> context['item'] = PurchaseOrderItem.objects.all()
> return context
>
>
> So basically what I'm trying to do is filter the
> PurchaseOrder.objects.get() so that the purchase_order.pk = the pk in the
> url, and then filter the PurchaseOrderItem.objects.get() so that the
> item.po_number_fk = purchase_order.pk
>
> Thanks again for all your help!
>
>
>
> On Friday, August 3, 2018 at 1:44:15 AM UTC-6, Andréas Kühne wrote:
>>
>> Hi,
>>
>> I think you are doing it right. I would remove the PurchaseOrderTotal
>> model however. The reason for this is that the purchase order itself should
>> know it's total and so on. Either you can add a signal on the save of the
>> PurchaseOrderItem - and update the PurchaseOrder total or the PurchaseOrder
>> could calculate the total when required via a method.
>>
>> I think the easiest way would be to add a method that calculates the
>> total:
>>
>> @property
>> def subtotal(self):
>> order_total = 0
>> for item in self.purchaseorderitem_set.all():
>> order_total += item.qty * item.unit_price
>> return order_total
>>
>> Now it is a property on the purchase order. So calling:
>> purchase_order.subtotal will get the total for the purchase order.
>>
>> 2 other things:
>> 1. You can remove the amount in the PurchaseOrderItem and calculate the
>> total for the row when required (see my example above) - this of course
>> depends on WHEN you want to show the total. The same thing goes for
>> calculating the total on the PurchaseOrder. You could add a property the
>> same way I did for the PurchaseOrder in the PurchaseOrderItem class.
>> 2. The names you have given your properties that are foreign keys are not
>> that good from an object oriented perspective. I would for example call the
>> invoice_number field on the PurchaseOrder as "invoice". The same goes for
>> the po_number_fk fields. Because when you assign them or when you want to
>> get a value from the invoice it would be easier to read -
>> purchase_order.invoice.id than purchase_order.invoice_number.id.
>>
>> Hope that helps somewhat.
>>
>> If you don't want to calculate the total each time (it all depends on the
>> usage), you can use signals to see when a model is saved/created and then
>> update the subtotal in the PurchaseOrder. See here for information about
>> signals: https://docs.djangoproject.com/en/2.0/topics/signals/
>>
>> Andréas
>>
>> 2018-08-02 19:27 GMT+02:00 Alexander Joseph <alexander...@gmail.com>:
>>
>>> I've been working on a Purchase Order app but I'm getting a little
>>> confused how I'm going to put it all together.
>>>
>>> I have 3 models -
>>>
>>> class PurchaseOrder(models.Model):
>>> po_number = models.IntegerField(default=get_po_number, unique=True)
>>> po_date = models.DateField()
>>> invoice_number = models.ForeignKey(Invoice, on_delete=models.CASCADE)
>>> ....
>>>
>>>
>>> class PurchaseOrderItem(models.Model):
>>> po_number_fk = models.ForeignKey(PurchaseOrder,
>>> on_delete=models.CASCADE)
>>> qty = models.IntegerField()
>>> unit = models.CharField(max_length=100, blank=True, null=True)
>>> description = models.CharField(max_length=255)
>>> unit_price = models.DecimalField(max_digits=6, decimal_places=2)
>>> amount = models.DecimalField(max_digits=6, decimal_places=2)
>>>
>>>
>>> class PurchaseOrderTotal(models.Model):
>>> po_number_fk = models.ForeignKey(PurchaseOrder,
>>> on_delete=models.CASCADE)
>>> subtotal = models.DecimalField(max_digits=6, decimal_places=2)
>>> tax = models.DecimalField(max_digits=6, decimal_places=2,
>>> default="7.82")
>>> shipping = models.DecimalField(max_digits=6, decimal_places=2)
>>> other = models.DecimalField(max_digits=6, decimal_places=2)
>>> total = models.DecimalField(max_digits=6, decimal_places=2)
>>>
>>>
>>> the first (PurchaseOrder) holds information about the purchase order
>>> itself. ie. what the invoice number is, the vendor, etc.
>>> the second (PurchaseOrderItem) lists items in the purchase order to
>>> purchase
>>> the third (PurchaseOrderTotal) totals up the amounts from the items and
>>> adds tax etc. (I may not need this model.. I can probably put this info in
>>> the first model?)
>>>
>>>
>>> Does it look like I'm going about this in the right way or should I take
>>> away the third model and put those fields from the third model into the
>>> first model? How do I total up all prices for all items? I'm sure I'll need
>>> to do some sort of loop to total up all prices but where do I do that? In
>>> the form_valid fucntion? or do I override the save function and do it
>>> there? Thanks!
>>>
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