Possibile fare un "in` 'lookup_type` attraverso il parser URL del filtro Django?

Question

Sto usando django-filtro con Django-Rest-Framework e sto cercando di istanziare un filtro che accetta elenchi di numeri per filtrare la query impostata

class MyFilter(django_filters.FilterSet):   
    ids = django_filters.NumberFilter(name='id',lookup_type='in')
    class Meta:
        model = MyModel
        fields = ('ids',)

class MyModelViewSet(viewsets.ModelViewSet):
    queryset = MyModel.objects.all()
    serializer_class = MyModelSerializer
    filter_class = MyFilter

.

Se passerò in un elenco di numeri interi separati da virgola, il filtro viene ignorato del tutto.

Se passo in un singolo numero intero, passa attraverso il filtro Django nel validatore della forma di Django e si lamenta:

'Decimal' object is not iterable

.

C'è un modo per creare un oggetto filtrante Django che può gestire un elenco di numeri interi e filtrare correttamente il querySet?

Answer 1

Per migliorare o peggio, ho creato un filtro personalizzato per questo:

class IntegerListFilter(django_filters.Filter):
    def filter(self,qs,value):
        if value not in (None,''):
            integers = [int(v) for v in value.split(',')]
            return qs.filter(**{'%s__%s'%(self.name, self.lookup_type):integers})
        return qs

.

che è usato come:

class MyFilter(django_filters.FilterSet):   
    ids = IntegerListFilter(name='id',lookup_type='in')
    class Meta:
        model = MyModel
        fields = ('ids',)

class MyModelViewSet(viewsets.ModelViewSet):
    queryset = MyModel.objects.all()
    serializer_class = MyModelSerializer
    filter_class = MyFilter

.

Ora la mia interfaccia accetta elenchi delimitati da virgole di interi.

Answer 2

So che questo è un vecchio post, ma ora c'è una soluzione migliore.Il cambiamento che lo rende corretto è pubblicato qui .

hanno aggiunto un BaseInFilter e un BaseRangeFilter.La documentazione è qui .

.

Immagine grande, Basefilter controlla il CSV e poi quando mescolato con un altro filtro fa ciò che stai chiedendo.Il tuo codice può ora essere scritto come:

class NumberInFilter(filters.BaseInFilter, filters.NumberFilter):
    pass

class MyModelViewSet(viewsets.ModelViewSet):
    ids = NumberInFilter(name='id', lookup_expr='in')

    class Meta:
        model = MyModel
        fields = ['ids']

.

Answer 3

Ecco una soluzione completa:

from django_filters import Filter, FilterSet
from rest_framework.filters import DjangoFilterBackend
from rest_framework.viewsets import ModelViewSet
from .models import User
from .serializers import UserSerializer


class ListFilter(Filter):

    def filter(self, qs, value):
        if not value:
            return qs

        self.lookup_type = 'in'
        values = value.split(',')
        return super(ListFilter, self).filter(qs, values)


class UserFilter(FilterSet):
    ids = ListFilter(name='id')

    class Meta:
        model = User
        fields = ['ids']


class UserViewSet(viewsets.ModelViewSet):
    serializer_class = UserSerializer
    queryset = User.objects.all()
    filter_backends = (DjangoFilterBackend,)
    filter_class = UserFilter

.

Answer 4

According to a post in the django-filter issues:

from django_filters import Filter
from django_filters.fields import Lookup

class ListFilter(Filter):
    def filter(self, qs, value):
        return super(ListFilter, self).filter(qs, Lookup(value.split(u","), "in"))

I have personally used this without any issue in my projects, and it works without having to create a per-type filter.

Answer 5

Based on @yndolok answer I have come to a general solution. I think filtering by a list of ids is a very common task and therefore should be included in the FilterBackend:

class ListFilter(django_filters.Filter):

    """Class to filter from list of integers."""

    def filter(self, qs, value):
        """Filter function."""
        if not value:
            return qs
        self.lookup_type = 'in'
        try:
            map(int, value.split(','))
            return super(ListFilter, self).filter(qs, value.split(','))
        except ValueError:
            return super(ListFilter, self).filter(qs, [None])


class FilterBackend(filters.DjangoFilterBackend):

    """A filter backend that includes ListFilter."""

    def get_filter_class(self, view, queryset=None):
        """Append ListFilter to AutoFilterSet."""
        filter_fields = getattr(view, 'filter_fields', None)

        if filter_fields:
            class AutoFilterSet(self.default_filter_set):
                ids = ListFilter(name='id')

                class Meta:
                    model = queryset.model
                    fields = list(filter_fields) + ["ids"]

            return AutoFilterSet

        else:
            return super(FilterBackend, self).get_filter_class(view, queryset)

Answer 6

Uptodate solution:

from django_filters import rest_framework as filters

name-->field_name

lookup_type-->lookup_expr

class IntegerListFilter(filters.Filter):
    def filter(self,qs,value):
        if value not in (None,''):
            integers = [int(v) for v in value.split(',')]
            return qs.filter(**{'%s__%s'%(self.field_name, self.lookup_expr):integers})
        return qs

class MyFilter(filters.FilterSet):   
    ids = IntegerListFilter(field_name='id',lookup_expr='in')
    class Meta:
        model = MyModel
        fields = ('ids',)

class MyModelViewSet(viewsets.ModelViewSet):
    queryset = MyModel.objects.all()
    serializer_class = MyModelSerializer
    filter_class = MyFilter

Answer 7

As I have answered here DjangoFilterBackend with multiple ids, it is now pretty easy to make a filter that accepts list and validates the contents

For Example:

from django_filters import rest_framework as filters


class NumberInFilter(filters.BaseInFilter, filters.NumberFilter):
    pass

class MyFilter(filters.FilterSet):
    id_in = NumberInFilter(field_name='id', lookup_expr='in')

    class Meta:
        model = MyModel
        fields = ['id_in', ]

This will accept a list of integers from a get parameter. For example /endpoint/?id_in=1,2,3