Coverage for website/thaliawebsite/api/v2/serializers/cleaned_model_serializer.py: 23.53%

1from django.core.exceptions import ValidationError 

2 

3from rest_framework import serializers 

4from rest_framework.exceptions import ValidationError as DRFValidationError 

5from rest_framework.serializers import raise_errors_on_nested_writes 

6from rest_framework.utils import model_meta 

7 

8 

9class CleanedModelSerializer(serializers.ModelSerializer): 

10 """Custom ModelSerializer that explicitly clean's a model before it is saved.""" 

11 

12 def create(self, validated_data): 

13 """Reraise ValidationErrors as DRF validation errors. 

14 

15 No need to explicitly clean(), because under the hood, DRF uses 

16 .create() which does perform a clean(). 

17 """ 

18 try: 

19 return super().create(validated_data) 

20 except ValidationError as e: 

21 raise DRFValidationError(e) from e 

22 

23 def update(self, instance, validated_data, **kwargs): 

24 """Override the default implementation of DRF's ModelSerializer. 

25 

26 Adds `instance.clean()` to make sure all updates still clean(). 

27 Also re-raises ValidationErrors to DRF ValidationErrors. 

28 """ 

29 raise_errors_on_nested_writes("update", self, validated_data) 

30 info = model_meta.get_field_info(instance) 

31 

32 # Simply set each attribute on the instance, and then save it. 

33 # Note that unlike `.create()` we don't need to treat many-to-many 

34 # relationships as being a special case. During updates we already 

35 # have an instance pk for the relationships to be associated with. 

36 m2m_fields = [] 

37 for attr, value in validated_data.items(): 

38 if attr in info.relations and info.relations[attr].to_many: 

39 m2m_fields.append((attr, value)) 

40 else: 

41 setattr(instance, attr, value) 

42 

43 try: 

44 instance.clean() 

45 except ValidationError as e: 

46 raise DRFValidationError(e) from e 

47 

48 instance.save() 

49 

50 # Note that many-to-many fields are set after updating instance. 

51 # Setting m2m fields triggers signals which could potentially change 

52 # updated instance and we do not want it to collide with .update() 

53 for attr, value in m2m_fields: 

54 field = getattr(instance, attr) 

55 field.set(value) 

56 

57 return instance