Django Custom model method with parameters, NON DRY - django

Question

After much research and trouble i came up with a non DRY solution, Hope someone can make it DRY.
All im trying to get is a calculated Price which takes a parameter and displays in the template accordingly.
i have a function get_price on model vehiclecategory which takes a parameter duration which is received from frontend forms.
MODELS.PY
class VehicleCategory(models.Model):
CATEGORY_CHOICES=(
('E-Cycle', 'E-Cycle'),
('E-Scooter', 'E-Scooter')
)
main_category = models.CharField(max_length=15, choices= CATEGORY_CHOICES)
title = models.CharField(unique=True, max_length=200)
image = models.ImageField(
null=True,
blank=True,
width_field="width_field",
height_field= "height_field",
default= 'e-bike.png',
upload_to='category')
width_field = models.IntegerField(default=250)
height_field = models.IntegerField(default=250)
slug =models.SlugField(max_length=200, db_index=True, unique=True)
def __str__(self):
return self.title
#GET PRICE
def get_price(self, duration):
for item in VehiclePrice.objects.all():
if item.vehicle_category.title == self.title and (duration >= item.slab.start and duration <= item.slab.end):
return item.total_price
class Meta():
verbose_name = "Vehicle Category"
verbose_name_plural = "Vehicle Categories"
class PriceSlab(models.Model):
start = models.IntegerField()
end = models.IntegerField()
timestamp = models.DateTimeField(auto_now_add=True)
def __str__(self):
return '%s - %s ' % (self.start, self.end)
class VehiclePrice(CustomerStatus):
help_text= "Ensure no more than 2 digits after decimal"
vehicle_category = models.ForeignKey(VehicleCategory, on_delete= models.SET_NULL, null=True, related_name='vehicle_category_price')
slab = models.ForeignKey(PriceSlab, on_delete=models.CASCADE)
net_price = models.DecimalField(help_text= help_text, max_digits=5, decimal_places=2)
tax_percent = models.DecimalField(help_text=help_text, max_digits=4, decimal_places=2, default=18.00)
discount_percent = models.DecimalField(help_text=help_text,max_digits=4, decimal_places=2, default=0, blank=True)
#property
def total_tax(self):
tax = (self.net_price * self.tax_percent)/100
return tax
#property
def get_price(self):
total = self.net_price + self.total_tax
return total
#property
def total_discount(self):
discount = (self.get_price * self.discount_percent)/100
return discount
#property
def total_price(self):
total = self.get_price - self.total_discount
return round(total)
class Meta():
unique_together=('customer_status','vehicle_category' ,'slab')
def __str__(self):
return '%s - %s - %s' % (self.customer_status, self.vehicle_category, self.slab)
VIEWS.PY
class HomeView(ListView):
template_name = 'app/home.html'
def get(self, request):
if request.method == "GET":
start_date = request.GET.get('start_date')
end_date = request.GET.get('end_date')
if start_date and end_date:
start_date = datetime.strptime(start_date, "%d/%m/%Y").date()
end_date = datetime.strptime(end_date, "%d/%m/%Y").date()
duration = (end_date - start_date).days +1
print(duration)
vehiclecategory= VehicleCategory.objects.all()
context = {
'price1': VehicleCategory.objects.get(main_category= 'E-Cycle', title="Sporty").get_price(duration),
'price2': VehicleCategory.objects.get(main_category= 'E-Cycle', title="Step-Through").get_price(duration),
'price3': VehicleCategory.objects.get(main_category= 'E-Cycle', title="Fatbike").get_price(duration),
'price4': VehicleCategory.objects.get(main_category= 'E-Scooter', title="Scooter").get_price(duration),
'vehiclecategory1': vehiclecategory.filter(main_category= 'E-Cycle', title="Sporty"),
'vehiclecategory1': vehiclecategory.filter(main_category= 'E-Cycle', title="Step-Through"),
'vehiclecategory1': vehiclecategory.filter(main_category= 'E-Cycle', title="Fatbike"),
'vehiclecategory2': vehiclecategory.filter(main_category= 'E-Scooter', title="Scooter"),
'form':CartQuantityForm(),
'dateform': DateForm(),
}
else:
context={'dateform': DateForm(),}
return render(request, self.template_name, context )
after the user inputs the date range, the vehicles are displayed, but when u go to the cart and come back the same page, the page refreshes as a new one. how can keep the date range values intact and render the same page as the user got first time he searched for a vehicle, so that he can add or modify the vehicles selected???

Answer 1

You may put your start & end dates into your URL.
You can create 2 urls record dispatching the same view:
path(r'/prices/', HomeView.as_view())
path(r'/prices/(?P<start>\d{4}-\d{2}-\d{2})_(?P<end>\d{4}-\d{2}-\d{2})', HomeView.as_view())
Then you need to make some changes in your view:
class HomeView(ListView):
template_name = 'app/home.html'
def get(self, request, **kwargs):
start = kwargs.get('start')
end = kwargs.get('end')
if start is None or end is None:
# Ask for dates & Redirect to its new url with dates.
else:
# Check the dates, convert them to date object & do the rest.
Maybe not the best solution but the first thing came to my mind is this one.