Django Rest 订购自定义

Question

我正在使用 django rest 框架，我想使用自定义方法订购。

所以，当我调用这个网址时，例如：http://127.0.0.1:8000/api/sets/?ordering=partMissing

可以调用自定义方法，因为我想订购 sn-p 缺少的零件数量。我计算了多对多字段中部分的总和。

Answer 1

我有非常简单的 POC，应该可以让您实施更复杂的解决方案。

views.py:

from rest_framework import viewsets

from ordering_test.models import Test
from ordering_test.ordering import MyCustomOrdering
from ordering_test.serializers import TestSerializer

class TestViewSet(viewsets.ModelViewSet):
    queryset = Test.objects.all()
    serializer_class = TestSerializer
    filter_backends = (MyCustomOrdering,)

ordering.py:

from rest_framework.filters import OrderingFilter

class MyCustomOrdering(OrderingFilter):

    allowed_custom_filters = ['testMethod']

    def get_ordering(self, request, queryset, view):
        """
        Ordering is set by a comma delimited ?ordering=... query parameter.

        The `ordering` query parameter can be overridden by setting
        the `ordering_param` value on the OrderingFilter or by
        specifying an `ORDERING_PARAM` value in the API settings.
        """
        params = request.query_params.get(self.ordering_param)

        if params:
            fields = [param.strip() for param in params.split(',')]
            # care with that - this will alow only custom ordering!
            ordering = [f for f in fields if f in self.allowed_custom_filters]
            if ordering:
                return ordering

        # No ordering was included, or all the ordering fields were invalid
        return self.get_default_ordering(view)

    def filter_queryset(self, request, queryset, view):

        ordering = self.get_ordering(request, queryset, view)
        if ordering:
            # implement a custom ordering here
            ordering = ['-id']

        if ordering:
            return queryset.order_by(*ordering)

        return queryset

models.py 和 serializers.py 很简单，但我仍将它们包括在这里：

models.py:

from django.db import models

class Test(models.Model):
    test = models.CharField(max_length=120)
    test1 = models.CharField(max_length=120)

serializers.py:

from rest_framework import serializers

from ordering_test.models import Test

class TestSerializer(serializers.ModelSerializer):

    class Meta:
        model = Test
        fields = ('test', 'test1')

编码愉快！

Answer 2

我认为 opalczynski 的解决方案更简单的方法是为自定义排序引入一个新字段：

from django import forms

import django_filters
from rest_framework import serializers

from .models import MyModel


class MyModelSerializer(serializers.ModelSerializer):

    class Meta:
        model = MyModel
        fields = ('field1',)


class CustomOrderingFilter(django_filters.FilterSet):
    order_by = django_filters.BooleanFilter(
        widget=forms.HiddenInput(),
        method='filter_order_by',
    )

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

    def filter_order_by(self, queryset, name, value):
        if value:
            return self.Meta.model.objects.filter(
                id__in=queryset.values_list('id', flat=True)
            ).order_by(value)

        return queryset

class TestViewSet(viewsets.ModelViewSet):
    queryset = MyModel.objects.all()
    serializer_class = MyModelSerializer
    filter_class = CustomOrderingFilter

然后您可以轻松地按您想要的任何字段排序：example.com/api/mymodel/?order_by=partMissing。

在我的示例中，我使用了固定模型字段，但您可以在 CustomOrderingFilter 上的 filter_order_by 方法中更改您的排序方式。只需将其更改为您想要的逻辑，但请确保使用.filter(=queryset.values_list('id', flat=True)) 以确保正在使用设置的其他过滤器。