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问如何将django rest过滤与mongoengine一起用于列表过滤
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Stack Overflow用户

提问于 2017-01-02 01:20:46

回答 2查看 979关注 0票数 3

views.py

from __future__ import unicode_literals

from rest_framework_mongoengine.viewsets import ModelViewSet as MongoModelViewSet

from app.serializers import *

from rest_framework_mongoengine.generics import * 

from rest_framework import filters    


def index_view(request):
    context = {}
    return TemplateResponse(request, 'index.html', context)


class ToolViewSet(MongoModelViewSet):
    serializer_class = ToolSerializer
    my_filter_fields = ('crop', 'district','taluka','circle','year',) 

    def get_kwargs_for_filtering(self):
        filtering_kwargs = {} 

        for field in  self.my_filter_fields: # iterate over the filter fields
            field_value = self.request.query_params.get(field) # get the value of a field from request query parameter
            if field_value: 
                filtering_kwargs[field] = field_value
        return filtering_kwargs 

    def get_queryset(self):
        queryset = Tool.objects.all() 
        filtering_kwargs = self.get_kwargs_for_filtering() # get the fields with values for filtering 
        if filtering_kwargs:
            queryset = Tool.objects.filter(**filtering_kwargs) # filter the queryset based on 'filtering_kwargs'
        return queryset

这是我的密码。

这是过滤我们想要讲的东西的工作。

例如：http://api/tool/?district=Nasik&crop=banana

但是，它不适用于列表文件--例如：http://api/tool/?district=Nasik&district=Pune --它给出了输出：空的

如何使该过滤器工作，以得到所有地区"Nasik“或区"Pune”

如果我搜索http://api/tool/?crops=guava,banana或http：./tool/? Pune =Nasik，Pune，请帮助我更改获取数据的代码。

给我正确的输出？

django-views

django-rest-framework

mongoengine

django-filter

restframeworkmongoengine

回答 2

Stack Overflow用户

回答已采纳

发布于 2017-01-03 00:19:55

我建议看一看django-rest框架-过滤器。然后，您可以在查询参数中使用诸如__in之类的内容..。

但是，如果您想继续您的方法，我将在您的get_kwargs_for_filtering方法中添加如下逻辑：

def get_kwargs_for_filtering(self):
    filtering_kwargs = {} 

    for field in  self.my_filter_fields: # iterate over the filter fields
        field_value = self.request.query_params.get(field) # get the value of a field from request query parameter
        if field_value: 
            if ',' in field_value: # put your queryParams into an array and use the built-in django filter method '__in'
                filtering_kwargs[field + '__in'] = field_value.split(',')
            else:
                filtering_kwargs[field] = field_value
    return filtering_kwargs

这样，对http://api/tool/?crops=guava,banana的调用就会产生所需的行为。我现在不能测试它是否有效，但这应该会指引你走向正确的方向。

票数 3

Stack Overflow用户

发布于 2022-11-22 05:37:14

虽然这个问题有点老了。在Django、DRF和MongoEngine的后续版本中，这个问题仍然是重要的和有效的。

在回答这个问题的时候，我正在跑

Django==4.1.3
djangorestframework==3.14
django-rest-framework-mongoengine==3.4.1
mongoengine==0.24.2
django-filter==22.1
# patched version of django-mongoengine-filter to support Django 4.0
# https://github.com/oussjarrousse/django-mongoengine-filter 
# Pull request https://github.com/barseghyanartur/django-mongoengine-filter/pull/16 
django-mongoengine-filter>=0.3.5

这个答案的思想是使用django-mongoengine-filter向django-mongoengine-filter添加过滤支持，这是django-filter的替代或扩展，应该与django-filter的工作方式相同。

首先，让我们编辑项目/setings.py文件。查找INSTALLED_APPS变量并确保添加了以下"Django应用程序“：

# in settings.py:

INSTALLED_APPS = [
    # ...,
    "rest_framework",
    "rest_framework_mongoengine",
    "django_filters",
    # ...,
]

应用程序django_filters需要添加与过滤基础设施相关的类，以及包括用于DRF的html模板在内的其他内容。

然后在变量REST_FRAMEWORK中，我们需要编辑与键DEFAULT_FILTER_BACKENDS相关联的值。

# in settings.py:

REST_FRAMEWORK = {
    # ...
    "DEFAULT_FILTER_BACKENDS": [
        "filters.DjangoMongoEngineFilterBackend",
        # ...
    ],
    # ...
}

DjangoMongoEngineFilterBackend是自定义构建的过滤器后端，我们需要将它添加到文件filters中的文件夹(取决于您如何构造项目)。

# in filters.py:
from django_filters.rest_framework.backends import DjangoFilterBackend

class DjangoMongoEngineFilterBackend(DjangoFilterBackend):
    # filterset_base = django_mongoengine_filter.FilterSet
    """
    Patching the DjangoFilterBackend to allow for MongoEngine support
    """

    def get_filterset_class(self, view, queryset=None):
        """
        Return the `FilterSet` class used to filter the queryset.
        """
        filterset_class = getattr(view, "filterset_class", None)
        filterset_fields = getattr(view, "filterset_fields", None)

        if filterset_class:
            filterset_model = filterset_class._meta.model

            # FilterSets do not need to specify a Meta class
            if filterset_model and queryset is not None:
                element = queryset.first()
                if element:
                    queryset_model = element.__class__
                    assert issubclass(
                        queryset_model, filterset_model
                    ), "FilterSet model %s does not match queryset model %s" % (
                        filterset_model,
                        str(queryset_model),
                    )

            return filterset_class

        if filterset_fields and queryset is not None:
            MetaBase = getattr(self.filterset_base, "Meta", object)

            element = queryset.first()
            if element:
                queryset_model = element.__class__
                class AutoFilterSet(self.filterset_base):
                    class Meta(MetaBase):
                        model = queryset_model
                        fields = filterset_fields

            return AutoFilterSet

        return None

此自定义筛选后端不会引发原始django过滤器后端将引发的异常。django-filter DjangoFilterBackend像在queryset.model中一样访问QuerySet中的键model，但是在MongoEngine中不存在该键。

也许应该考虑在MongoEngine中提供它：https://github.com/MongoEngine/mongoengine/issues/2707 https://github.com/umutbozkurt/django-rest-framework-mongoengine/issues/294

现在，我们可以向ViewSet添加一个自定义筛选器：

# in views.py
from rest_framework_mongoengine.viewsets import ModelViewSet

class MyModelViewSet(ModelViewSet):
    serializer_class = MyModelSerializer
    filter_fields = ["a_string_field", "a_boolean_field"]
    filterset_class = MyModelFilter

    def get_queryset(self):
        queryset = MyModel.objects.all()
        return queryset

最后，让我们回到filters.py并添加MyModelFilter

# in filters.py
from django_mongoengine_filter import FilterSet, StringField, BooleanField
class MyModelFilter(FilterSet):
    """
    MyModelFilter is a FilterSet that is designed to work with the django-filter.
    However the original django-mongoengine-filter is outdated and is causing some troubles
    with Django>=4.0.
    """

    class Meta:
        model = MyModel
        fields = [
            "a_string_field",
            "a_boolean_field",
        ]

    a_string_field = StringFilter()
    a_boolean_field = BooleanFilter()