How to get the id of a current object in Django serializers?

Question

I have a model, 'Project'. The idea is that, a user will log in and create a project. After creating, the user will work on this project at any time. Certain details will be saved to other models where I have written custom functions for it in Serializers.py.

In order solve the idea I have, I need to retrieve the id of the current project that the user is currently working on in Serializers.py. Below is my code:

View.py

class MaterialTagExcelViewSet(FilteredModelViewSet):
    queryset = MaterialTagExcel.objects.all()
    serializer_class = MaterialTagExcelSerializer
    permission_classes = (IsAuthenticated,)
    http_method_names = ('get', 'head', 'post', 'options', 'patch')

Serializers.py

class MaterialTagExcelSerializer(BaseSerializer):

    class Meta:
        fields = "__all__"
        model = MaterialTagExcel

    def create(self, validated_data):
        name = validated_data.get('name')  # get current material name

        if name is not None: 
            name_tag = MaterialTagExcel.objects.filter(name=name).first()  # filter name to check if it already exists

            client = self.context['request'].user.profile.client  # get current client details

            if name_tag is not None:  # if name exists
                objects = MaterialExcelClient.objects.filter(client_id=client.id, name_id=name_tag.id)

                if objects.count() == 0:
                    material_excel_client = MaterialExcelClient(client_id=client.id, name_id=name_tag.id)
                    material_excel_client.save()  # get current id and mat id and save to material_client_excel
                    return MaterialExcelClient.objects.filter(name_id=name_tag.id).order_by('-id')[0]
                else:
                    return MaterialExcelClient.objects.filter(client_id=client.id, name_id=name_tag.id).first()

            else:
                MaterialTagExcel.objects.create(**validated_data)
                MaterialTagExcel.objects.all()  # save if material is new and does not exist

                # return the id of this newly created material
                obj = MaterialTagExcel.objects.filter(name=name).order_by('-id')[0]
                # save the id of the newly created material and current client id into material_excel_client
                material_excel_client = MaterialExcelClient(client_id=client.id, name_id=obj.id)
                material_excel_client.save()
                return MaterialExcelClient.objects.filter(name_id=obj.id).order_by('-id')[0]

From above serializer, I am able to get the client.id with the help of CurrentUserDefault. In my table user is related to profile and profile is related to client but not project. I tried to with a custom CurrentProjectDefault, but I didnt succeeded. I tried with many online sources to solve my problem.

Is there any way to get the id of the current object from client ? I am apologizing in advance if the solution to my problem is very simple.

If you would need some more details, kindly write it in comment.

Thanks in advance.

Models.py

class MaterialTagExcel():
    name = models.CharField(max_length=255, verbose_name='name', null=False, blank=False) 

    def __str__(self):
        return "Material %s: %s" % (self.id, self.name)

    @classmethod
    def get_queryset_for_user(cls, user):
        return cls.objects.all()

class Project():
    client =    models.ForeignKey(Client, related_name='projects', on_delete=models.PROTECT)

    name =                models.CharField(max_length=255)

class ToDo(BaseModel):
    project = models.ForeignKey(Project, related_name='todos', on_delete=models.CASCADE)
    owner_client = models.ForeignKey(Client, related_name='todos', on_delete=models.CASCADE)

Answer 1

You wish to retrieve the current project the user is working on. The goal of a REST API is to be stateless, which roughly means that the request contains all the necessary information to perform its action without relying on an external context.

This means that you have to provide the current project id in each of your request.

So, in your example, when you want to POST a new MaterialTagExcel, you'll have to provide the Project. You can modify your serializer like this to do so:

class MaterialTagExcelSerializer(BaseSerializer):
    project = serializers.PrimaryKeyRelatedField(write_only=True, queryset=Project.objects.all())

    class Meta:
        fields = "__all__"
        model = MaterialTagExcel

    def create(self, validated_data):

        name = validated_data.get('name')  
        project = validated_data.pop('project') # A Project object

Now, when you're doing a request, you'll have to specify the property project with the id. of the project the user has selected in the menu.