How do I call custom Django Model Manager from Class Based View?-CodePudding

I would like to use a customer model manager that manipulates a field but does not save to the database. How do I call the model manager function named "with_counts()" in the sample code below.

Is it possible to call it from my view or my templates?

    LEVEL = [
        ('Pro', 'Professional'),
        ('Int', 'Intermediate'),
        ('OK', 'Competent')
    ]

    Languages = models.CharField(max_length=25)
    Years = models.IntegerField(default=1)
    Proficiency = models.CharField(max_length=15, choices=LEVEL, default="Competent")


    def __str__(self):
        return f'{self.Languages} Level: {self.Proficiency}'


    #Do not save to data base. 
    def with_counts(self):
        return self.years * 10;

CodePudding user response：

Just add a @property to your model:

@property
def with_counts(self):
    return self.Years * 10;

See https://docs.djangoproject.com/en/4.0/glossary/#term-property and https://docs.python.org/3/library/functions.html#property for further details.

P.S. you should use lower-case model field names.

CodePudding user response：

From the docs:

A custom Manager method can return anything you want. It doesn’t have to return a QuerySet.

So in that can you are right you can just call that as a normal function in your view like this:

views.py:

class your_view(View):
 def get(request, *args, **kwargs):
   counts = YourModal.objects.with_counts()
   # do something with counts

models.py:

class YourModel(models.Model):
  objects = models.YourManager()

managers.py:

class YourManager(models.Manager):
 def with_counts(self):
    return self.years * 10