可能通过django-filter URL解析器做一个`in``lookup_type`？

Question

我正在使用 django-过滤器 与 django-rest-框架 我正在尝试实例化一个过滤器，该过滤器接受数字列表以过滤查询集

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

如果我传入以逗号分隔的整数列表，则会完全忽略过滤器。

如果我传入一个整数，它通过django-filter进入django的表单验证器并抱怨:

'Decimal' object is not iterable

有没有办法创建一个django-filter对象，它可以处理整数列表并正确过滤queryset？

Answer 1

无论好坏，我为此创建了一个自定义过滤器：

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

.

使用：

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

.

现在我的界面接受逗号分隔的整数列表。

Answer 2

我知道这是一个旧帖子，但现在有一个更好的解决方案。使其正确的更改已发布 这里.

他们增加了一个 BaseInFilter 和一个 BaseRangeFilter.文件是 这里.

大图，BaseFilter检查CSV，然后当与另一个过滤器混合时，它会做你所要求的。你的代码现在可以写成:

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

这是一个完整的解决方案：

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