python - 在 Django REST Framework 中公开 MoneyFields？

Question

我有一些使用 djmoney.models.fields.MoneyField 的 Django 模型。这会存储诸如“1,000.00 美元”之类的数据。

我正在尝试通过 API 与 Django REST Framework 公开它直接在 Django 的管理员中使用自定义 View ，例如:

from rest_framework import generics
from rest_framework import serializers

class MyModelAdmin(admin.ModelAdmin):

    def changelist_view_api(self, request, extra_context=None):

        cl = self.get_changelist_instance(request)
        base_queryset = cl.get_queryset(request)

        fieldsets = self.get_fieldsets(request)

        class ModelSerializer(serializers.ModelSerializer):

            class Meta:
                model = self.model
                fields = all_fields

        class ModelAdminListAPI(generics.ListCreateAPIView):
            queryset = base_queryset
            serializer_class = ModelSerializer

            name = '%s List API' % self.model._meta.verbose_name.title()

            def get(self, request, *args, **kwargs):
                return self.list(request, *args, **kwargs)

        view_handler = ModelAdminListAPI.as_view(queryset=base_queryset, serializer_class=ModelSerializer)
        return view_handler(request, extra_context, format=_format)

这很好用，唯一的异常(exception)是它会阻塞这些特殊的 MoneyField 实例。对于字段列表中的其中一个，此 View 返回异常:

  File "~/.env/lib/python3.7/site-packages/rest_framework/mixins.py", line 43, in list
    return self.get_paginated_response(serializer.data)
  File "~/.env/lib/python3.7/site-packages/rest_framework/serializers.py", line 761, in data
    ret = super().data
  File "~/.env/lib/python3.7/site-packages/rest_framework/serializers.py", line 260, in data
    self._data = self.to_representation(self.instance)
  File "~/.env/lib/python3.7/site-packages/rest_framework/serializers.py", line 679, in to_representation
    self.child.to_representation(item) for item in iterable
  File "~/.env/lib/python3.7/site-packages/rest_framework/serializers.py", line 679, in <listcomp>
    self.child.to_representation(item) for item in iterable
  File "~/.env/lib/python3.7/site-packages/rest_framework/serializers.py", line 530, in to_representation
    ret[field.field_name] = field.to_representation(attribute)
  File "~/.env/lib/python3.7/site-packages/rest_framework/fields.py", line 1148, in to_representation
    value = decimal.Decimal(str(value).strip())
decimal.InvalidOperation: [<class 'decimal.ConversionSyntax'>]

深入研究 DRF 的内部结构，它似乎将 MoneyField 视为 DecimalField，因为它是从中继承的。但是，djmoney 还创建了另一个名为 *_currency 的 CharField，用于存储货币面额(例如“USD”)。然后，当您请求货币字段的逻辑值时，它会将小数和货币值组合成格式“”。

我认为 DRF 在尝试将此值解释为小数时遇到了问题。

这是 DRF 中的错误还是我配置错误？如何允许 DRF 正确解释 MoneyField 值？

Answer 1

我有同样的问题，通过将 'djmoney', 添加到 INSTALLED_APPS 来解决。当您执行此操作时，MoneyField 将为转换和所有工作注入(inject)正确的序列化程序字段。喂:-)