Refactor Business Logic From View To Model-CodePudding

I've got a django view with a small amount of business logic in it. However it would be useful to use this information elsewhere so it feels like something that I could put into a model however I'm not entirely sure how to go about doing this. Mainly because I need specific user data. This is what I have so far:

views.py

    def create_budget(self, context):
        starting_point = BudgetStartingPoint.objects.filter(owner=self.request.user)

        running_tally = starting_point[0].starting_amount

        budget_dict = {}
        for transaction in self.get_queryset():
            if transaction.income_type == "IN":
                running_tally  = transaction.transaction_amount
            else:
                running_tally -= transaction.transaction_amount

            budget_dict[transaction] = [running_tally, transaction.income_type]

        context['budget'] = budget_dict

models.py

class BudgetTransaction(models.Model):
    """
    Individual transaction for Budget
    """

    transaction_types = [
        ('fixed', 'Fixed'),
        ('extra', 'Extra'),
    ]

    income_types = [
        ("IN", "Income"),
        ("OUT", "Expense"),
    ]

    frequencies = [
        ('weeks', 'Weekly'),
        ('fort', 'Fortnightly'),
        ('4week', 'Four Weeks'),
        ('months', 'Monthly'),
        ('years', 'Yearly'),
    ]

    today = datetime.today().date()

    id = HashidAutoField(
        primary_key=True, salt=f"transaction{settings.HASHID_FIELD_SALT}"
    )
    owner = models.ForeignKey(
        settings.AUTH_USER_MODEL,
        on_delete=models.CASCADE,
        help_text="Owner of the item"
    )
    category = models.ForeignKey(BudgetCategory, on_delete=models.CASCADE, default=1, null=True)
    transaction_type = models.CharField(max_length=40, choices=transaction_types, default=1)
    transaction_name = models.CharField(max_length=100, null=False)
    transaction_amount = models.FloatField(null=False, default=100)
    income_type = models.CharField(max_length=20, choices=income_types, default="IN")
    next_date = models.DateField(null=False, default=today)
    frequency = models.CharField(max_length=20, choices=frequencies, default=1)
    complete = models.BooleanField(default=False)

    def __str__(self):
        return self.transaction_name

    class Meta:
        ordering = ['next_date']

I feel like I have a lot of things that would be nice to have as a model method but they need to get the current user which I'm not sure how to do.

CodePudding user response：

Not sure if this is what you mean but you can do:

def create_budget(self, context):
    starting_point = BudgetStartingPoint.objects.filter(owner=self.request.user)

    running_tally = starting_point[0].starting_amount

    budget_dict = {}
    for transaction in self.get_queryset():
        running_tally = transaction.get_change(running_tally)
        budget_dict[transaction] = [running_tally, transaction.income_type]

    context['budget'] = budget_dict

class BudgetTransaction(models.Model):
    ....
    def get_change(self,value):
        return value   (
            self.transaction_amount 
            if self.income_type == "IN" else 
            -self.transaction_amount
        )