Refactor models serializer M2M logic

This commit is contained in:
sevdog 2022-04-04 12:39:21 +02:00
parent df92e57ad6
commit b4a6e1a2e0

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@ -923,6 +923,12 @@ class ModelSerializer(Serializer):
# "HTTP 201 Created" responses. # "HTTP 201 Created" responses.
url_field_name = None url_field_name = None
def save_m2m(self, instance, m2m_fields):
"""Create or update many-to-many relationships."""
for field_name, value in m2m_fields.items():
field = getattr(instance, field_name)
field.set(value)
# Default `create` and `update` behavior... # Default `create` and `update` behavior...
def create(self, validated_data): def create(self, validated_data):
""" """
@ -953,10 +959,10 @@ class ModelSerializer(Serializer):
# They are not valid arguments to the default `.create()` method, # They are not valid arguments to the default `.create()` method,
# as they require that the instance has already been saved. # as they require that the instance has already been saved.
info = model_meta.get_field_info(ModelClass) info = model_meta.get_field_info(ModelClass)
many_to_many = {} m2m_fields = {}
for field_name, relation_info in info.relations.items(): for field_name, relation_info in info.relations.items():
if relation_info.to_many and (field_name in validated_data): if relation_info.to_many and (field_name in validated_data):
many_to_many[field_name] = validated_data.pop(field_name) m2m_fields[field_name] = validated_data.pop(field_name)
try: try:
instance = ModelClass._default_manager.create(**validated_data) instance = ModelClass._default_manager.create(**validated_data)
@ -981,10 +987,7 @@ class ModelSerializer(Serializer):
raise TypeError(msg) raise TypeError(msg)
# Save many-to-many relationships after the instance is created. # Save many-to-many relationships after the instance is created.
if many_to_many: self.save_m2m(instance, m2m_fields)
for field_name, value in many_to_many.items():
field = getattr(instance, field_name)
field.set(value)
return instance return instance
@ -996,10 +999,10 @@ class ModelSerializer(Serializer):
# Note that unlike `.create()` we don't need to treat many-to-many # Note that unlike `.create()` we don't need to treat many-to-many
# relationships as being a special case. During updates we already # relationships as being a special case. During updates we already
# have an instance pk for the relationships to be associated with. # have an instance pk for the relationships to be associated with.
m2m_fields = [] m2m_fields = {}
for attr, value in validated_data.items(): for attr, value in validated_data.items():
if attr in info.relations and info.relations[attr].to_many: if attr in info.relations and info.relations[attr].to_many:
m2m_fields.append((attr, value)) m2m_fields[attr] = value
else: else:
setattr(instance, attr, value) setattr(instance, attr, value)
@ -1008,9 +1011,7 @@ class ModelSerializer(Serializer):
# Note that many-to-many fields are set after updating instance. # Note that many-to-many fields are set after updating instance.
# Setting m2m fields triggers signals which could potentially change # Setting m2m fields triggers signals which could potentially change
# updated instance and we do not want it to collide with .update() # updated instance and we do not want it to collide with .update()
for attr, value in m2m_fields: self.save_m2m(instance, m2m_fields)
field = getattr(instance, attr)
field.set(value)
return instance return instance