Fluent interface on custom methods of custom Queryset class

[Fabio C. Barrionuevo da Luz]

What is the right way to make Fluent interface on custom methods of custom Queryset class?

In other words, how to make "by_validity" work without lost previous filters?

Procedure.objects.filter(is_active=False).by_validity()


I've tried using q = self or q = self.query before apply Q(start_date__lte=start_date) & (Q(end_date=None) | Q(end_date__gte=end_date)) , But it did not work, I got errors.

Thanks.

sample code:

from datetime import date, datetime, time

from django.conf import settings

from django.db import models

from django.db.models import Q

class ProcedureQuerySet(models.QuerySet):

    def by_validity(self, start_date=None, end_date=None):

        if not start_date:

            start_date = date.today()

        if start_date and not end_date:

            end_date = start_date

        if end_date < start_date:

            raise ValueError("end_date must be greater than start_date")

        start_date = datetime.combine(start_date, time.min)

        end_date = datetime.combine(end_date, time.max)

        q = Q(start_date__lte=start_date) & (Q(end_date=None) | Q(end_date__gte=end_date))

        return self.filter(q)

class ProcedureManager(models.Manager.from_queryset(ProcedureQuerySet)):

    pass

class Procedure(models.Model):

    start_date = models.DateTimeField()

    end_date = models.DateTimeField(null=True)

    is_active = models.BooleanField(default=True)

    objects = ProcedureManager()

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Fábio C. Barrionuevo da Luz
Palmas - Tocantins - Brasil - América do Sul

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[Felippe Raposo]

Hey Fabio, according to the Django documentation the right way would be:

ProcedureManager = models.Manager.from_queryset(ProcedureQuerySet)

class Procedure(models.Model):

    start_date = models.DateTimeField()

    end_date = models.DateTimeField(null=True)

    is_active = models.BooleanField(default=True)

    objects = ProcedureManager()

or

class Procedure(models.Model):

    start_date = models.DateTimeField()

    end_date = models.DateTimeField(null=True)

    is_active = models.BooleanField(default=True)

    objects = models.Manager.from_queryset(ProcedureQuerySet)()

Warmly,
Felippe Raposo

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