DRF. Filtering child's class objects linked to parrent with ForeignKey from a parent class api routing

huangapple
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英文:

DRF. Filtering child's class objects linked to parrent with ForeignKey from a parent class api routing

问题

I've translated the code-related parts of your text:

products/models.py

  1. class Product(models.Model):
  2.     """Model representing a product."""
  3.     id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)
  4.     name = models.CharField(max_length=255)
  5.     category = models.ForeignKey(Category, on_delete=models.CASCADE, related_name='products')
  6.     brand = models.ForeignKey('Brand', on_delete=models.CASCADE, related_name='products')
  7.     slug = models.SlugField(unique=True, blank=True, default=id)
  9. class Brand(models.Model):
  10.     """A model representing the brand of the product."""
  11.     id = models.AutoField(primary_key=True, editable=False)
  12.     name = models.CharField(max_length=255)
  13.     slug = models.SlugField(unique=True, editable=False)

products/serializers.py

  1. class ProductSerializer(serializers.ModelSerializer):
  2.     class Meta:
  3.         model = Product
  4.         fields = '__all__'

products/views.py

  1. class ProductViewSet(viewsets.ModelViewSet):
  2.     queryset = Product.objects.all()
  3.     serializer_class = ProductSerializer
  4.     lookup_field = 'slug'

products/urls.py

  1. router = DefaultRouter()
  2. router.register("", ProductViewSet)
  4. urlpatterns = [
  5.     path("", include(router.urls)),
  6. ]

categories/models.py

  1. class Category(MPTTModel):
  2.     """Category model inherits from a side application class MPTT designed for more
  3.     convenient work with model tree structure."""
  4.     
  5.     objects = CategoryManager()  # Use of a custom manager defined above
  6.     
  7.     id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)
  8.     name = models.CharField(max_length=120, db_index=True, unique=True)
  9.     slug = models.SlugField(unique=True)
  10.     parent = TreeForeignKey(
  11.         "self",
  12.         blank=True,
  13.         null=True,
  14.         related_name="child",
  15.         on_delete=models.CASCADE
  16.     )

categories/serializers.py

  1. class RecursiveField(serializers.Serializer):
  2.     def to_representation(self, value):
  3.         serializer = self.parent.parent.__class__(value, context=self.context)
  4.         return serializer.data
  6. class CategorySerializer(serializers.ModelSerializer):
  7.     child = RecursiveField(many=True, read_only=True)

categories/views.py

  1. class CategoriesAPIViewSet(viewsets.ModelViewSet):
  2.     """Standard ModelViewSet which implements CRUD with minor changes."""
  3.     queryset = Category.objects.all()
  4.     serializer_class = CategorySerializer
  5.     lookup_field = 'slug'

categories/urls.py

  1. router = SimpleRouter()
  2. router.register("", CategoriesAPIViewSet)
  4. urlpatterns += router.urls

These translations should help you understand and work with the code in a Chinese context.

英文:

I work on some kind of e-commercial shop (just for learning purpose).
I have parent model Category and child model Product which has a field category which references to Category object with Many-To-One relations (ForeignKey).
Idea is to make filtration from a parent class e.g. Category to retrieve all Product objects matches with given paramenter(s).

For example:
When I send a request to route "localhost/api/categories/" I get all categories and subcategories (just for wider vision: subcategory routing also works. If i send request to localhost/api/categories/smartphones/ it returns a response with subcategories which are children of smartphones and so on).
Now I want to implement filtering in such way : when I send a request to route "localhost/api/categories/smartphones/brand?=apple" it has to return all Product objects with brand field equal to "apple". And this pattern has to work for any category so I don't have to hardcode apple as Category object for every single category that might contain Apple devices.

My code right now (not all lines included but most important) :

products/models.py

  1. class Product(models.Model):
  2. """Model representing a product."""
  3. id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)
  4. name = models.CharField(max_length=255)
  5. category = models.ForeignKey(Category, on_delete=models.CASCADE, related_name='products')
  6. brand = models.ForeignKey('Brand', on_delete=models.CASCADE, related_name='products')
  7. slug = models.SlugField(unique=True, blank=True, default=id)
  9. class Brand(models.Model):
  10.     """A model representing the brand of the product."""
  11.     id = models.AutoField(primary_key=True, editable=False)
  12.     name = models.CharField(max_length=255)
  13.     slug = models.SlugField(unique=True, editable=False)

products/serializers.py

  1. class ProductSerializer(serializers.ModelSerializer):
  2.     class Meta:
  3.         model = Product
  4.         fields = '__all__'

products/views.py

  1. class ProductViewSet(viewsets.ModelViewSet):
  2.     queryset = Product.objects.all()
  3.     serializer_class = ProductSerializer
  4.     lookup_field = 'slug'

products/urls.py

  1. router = DefaultRouter()
  2. router.register("", ProductViewSet)
  4. urlpatterns = [
  5.     path("", include(router.urls)),
  6. ]

categories/models.py

  1. class Category(MPTTModel):
  2. """ Category model inherits from a side application class MPTT designed for more
  3. convenient work with model tree structure """
  5. objects = CategoryManager()  # Use of a custom manager defined above
  7. id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)
  8. name = models.CharField(max_length=120, db_index=True, unique=True)
  9. slug = models.SlugField(unique=True)
  10. parent = TreeForeignKey(   # MPTT model Field represents a parent of subcategory (if exists) in tree structure.
  11.     "self",
  12.     blank=True,
  13.     null=True,
  14.     related_name="child",
  15.     on_delete=models.CASCADE
  16. )

categories/serializers.py

  1. class RecursiveField(serializers.Serializer):
  2.     def to_representation(self, value):
  3.         serializer = self.parent.parent.__class__(value, context=self.context)
  4.         return serializer.data
  7. class CategorySerializer(serializers.ModelSerializer):
  8.     child = RecursiveField(many=True, read_only=True)

categories/views.py
class CategoriesAPIViewSet(viewsets.ModelViewSet):

  1. """ Standard ModelViewSet which implements CRUD with minor changes. """
  3. queryset = Category.objects.all()
  4. serializer_class = CategorySerializer
  5. lookup_field = 'slug'

categories/urls.py

  1. router = SimpleRouter()
  3. router.register("", CategoriesAPIViewSet)
  5. urlpatterns += router.urls

答案1

得分: 0

如下所述：https://www.django-rest-framework.org/api-guide/viewsets/#modelviewset，您可以实现get_queryset方法，以根据请求提供不同的查询集。

您可以使用self.request.query_params来访问已发送的brand，请参考：https://www.django-rest-framework.org/api-guide/requests/#query_params

因此，您的方法可能如下所示：

  1. def get_queryset(self):
  2.   return Product.objects.filter(brand=self.request.query_params['brand'])

或类似的方法。

根据评论进行编辑：

如果查询参数是可选的，您可以这样做：

  1. def get_queryset(self):
  2.   if 'brand' in self.request.query_params:
  3.     return Product.objects.filter(brand=self.request.query_params['brand'])
  4.   return Product.objects.all()
英文:

As mentioned at https://www.django-rest-framework.org/api-guide/viewsets/#modelviewset , you can implement the get_queryset method to provide a different queryset based on the request.

You can use self.request.query_params to access the brand that has been sent, https://www.django-rest-framework.org/api-guide/requests/#query_params

So your method might look like:

  1. def get_queryset(self):
  2.   return Product.objects.filter(brand=self.request.query_params['brand'])

Or similar DRF. Filtering child's class objects linked to parrent with ForeignKey from a parent class api routing

EDIT based on comment:

If the query param is optional, you could do this:

  1. def get_queryset(self):
  2.   if 'brand' in self.request.query_params:
  3.     return Product.objects.filter(brand=self.request.query_params['brand'])
  4.   return Product.objects.all()

huangapple
  • 本文由 发表于 2023年5月24日 22:11:07
  • 转载请务必保留本文链接：https://go.coder-hub.com/76324497.html
  • django
  • django-filter
  • django-rest-framework
  • python
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