How to implement ForeignKey with Django serializer - json

Question

I have this models:
class Discipline(models.Model):
name = models.CharField(max_length=200)
class Lesson(models.Model):
discipline = models.ForeignKey(Discipline, on_delete=models.CASCADE, null=True)
date = models.DateField()
regular_slot = models.BooleanField(default=False)
And these serializers:
class DisciplineSerializer(serializers.ModelSerializer):
class Meta:
model = Discipline
fields = ('name')
class LessonSerializer(serializers.ModelSerializer):
discipline = serializers.RelatedField(source='Discipline', read_only=True);
class Meta:
model = Lesson
fields = ('discipline', 'date', 'regular_slot')
I have a view to process a JSON request and to save the data:
def cours_list(request):
if request.method == 'POST':
data = JSONParser().parse(request)
serializer = LessonSerializer(data=data)
if serializer.is_valid():
serializer.save()
return JSONResponse(serializer.data, status=201)
return JSONResponse(serializer.errors, status=400)
My JSON request is as follows:
{"discipline":"Mathematiques","date":"2017-12-03"}
However, I have an error saying that:
'Lesson' object has no attribute 'Discipline'
I believe this is because attribute discipline in Lesson refers only to the id and is not of type Discipline. I could'nt find how to solve this. Is the way I define foreignKey is not correct ?
How to insert a foreignKey reference here while I receive a Discipline object from the JSON request ?

Answer 1

I'm going to help you also with this :)
class DisciplineSerializer(serializers.ModelSerializer):
class Meta:
model = Discipline
fields = ('name')
class LessonSerializer(serializers.ModelSerializer):
discipline = DiscliplineSerializer()
class Meta:
model = Lesson
fields = ('discipline', 'date', 'regular_slot')
Doing this is enough as far as I know.
Edit: Reason of your error is that you write "source="Discipline"" but there is no field named Discipline in your Lesson model. Therefore, it gives an error.