我试图弄清楚如何使用Django REST框架保存相关模型。
在我的应用中,我有一个模型Recipe
,其中包含2个相关模型:RecipeIngredient
和RecipeStep
。 Recipe
对象必须至少包含3个相关RecipeIngredient
和3 RecipeStep
。在引入REST框架之前,我使用了带有两个formset的Django CreateView
,并且保存过程如下(遵循form_valid()
中的代码):
def save_formsets(self, recipe):
for f in self.get_formsets():
f.instance = recipe
f.save()
def save(self, form):
with transaction.atomic():
recipe = form.save()
self.save_formsets(recipe)
return recipe
def formsets_are_valid(self):
return all(f.is_valid() for f in self.get_formsets())
def form_valid(self, form):
try:
if self.formsets_are_valid():
try:
return self.create_ajax_success_response(form)
except IntegrityError as ie:
return self.create_ajax_error_response(form, {'IntegrityError': ie.message})
except ValidationError as ve:
return self.create_ajax_error_response(form, {'ValidationError': ve.message})
return self.create_ajax_error_response(form)
现在我有RecipeViewSet
:
class RecipeViewSet(ModelViewSet):
serializer_class = RecipeSerializer
queryset = Recipe.objects.all()
permission_classes = (RecipeModelPermission, )
使用RecipeSerializer
:
class RecipeSerializer(serializers.ModelSerializer):
class Meta:
model = Recipe
fields = (
'name', 'dish_type', 'cooking_time', 'steps', 'ingredients'
)
ingredients = RecipeIngredientSerializer(many=True)
steps = RecipeStepSerializer(many=True)
这些是相关的序列化器:
class RecipeIngredientSerializer(serializers.ModelSerializer):
class Meta:
model = RecipeIngredient
fields = ('name', 'quantity', 'unit_of_measure')
class RecipeStepSerializer(serializers.ModelSerializer):
class Meta:
model = RecipeStep
fields = ('description', 'photo')
现在......我应该如何验证相关模型(RecipeIngredient
和RecipeStep
)并在RecipeViewSet
create()
时保存它们方法被称为? ({1}}中的is_valid()
实际上忽略了嵌套关系,仅报告与主模型RecipeSerializer
相关的错误。
目前我试图覆盖Recipe
中的is_valid()
方法,但不是那么简单......任何想法?
答案 0 :(得分:17)
我本周正在处理类似的问题而且我发现,django rest framework 3实际上支持嵌套可写序列化(http://www.django-rest-framework.org/topics/3.0-announcement/#serializers在子章节可写嵌套序列化中。)
我不确定嵌套的序列化程序是否可写是默认的,所以我声明了它们:
ingredients = RecipeIngredientSerializer(many=True, read_only=False)
steps = RecipeStepSerializer(many=True, read_only=False)
你应该在RecipeSerializer中重写你的创建方法:
class RecipeSerializer(serializers.ModelSerializer):
ingredients = RecipeIngredientSerializer(many=True, read_only=False)
steps = RecipeStepSerializer(many=True, read_only=False)
class Meta:
model = Recipe
fields = (
'name', 'dish_type', 'cooking_time', 'steps', 'ingredients'
)
def create(self, validated_data):
ingredients_data = validated_data.pop('ingredients')
steps_data = validated_data.pop('steps')
recipe = Recipe.objects.create(**validated_data)
for ingredient in ingredients_data:
#any ingredient logic here
Ingredient.objects.create(recipe=recipe, **ingredient)
for step in steps_data:
#any step logic here
Step.objects.create(recipe=recipe, **step)
return recipe
如果这个结构Step.objects.create(recipe = recipe,** step)不起作用,也许你必须从steps_data / ingredients_data中分别选择代表每个字段的数据。
这是我在堆栈上的早期(实际)问题/答案的链接:How to create multiple objects (related) with one request in DRF?
答案 1 :(得分:1)
我认为我得到了答案。
class RecetaSerializer(serializers.ModelSerializer):
position: absolute;
重写to_internal_value()很重要。我遇到了函数is_valid()的问题。因此,函数to_internal_value()中的每个更改都在函数is_valid()
之前