我想创建一个像web应用程序的udemy,并使用django rest框架作为后端,mysql作为数据库。我有一个名为“课程”的模型,其中包含所有课程的列表,其中一个字段是“视频链接”。我还有另一个模型名称购买有两个ForeignKey字段:用户和课程。我想向所有用户展示课程,但是对于下载字段,我必须在购买中查找对(用户,课程),如果他有课程,我将向他显示下载字段。
class LessonsViewSet(viewsets.ModelViewSet):
queryset = models.Assignments.objects.all()
authentication_classes = (TokenAuthentication,)
def get_serializer_class(self):
if self.request.user.is_staff :
print(self.request.user)
return serializers.FullAccessLessonsSerializer
elif self.request.user.is_active:
return serializers.PartialAccessLessonsSerializer
print(self.request.user)
return serializers.BasicAccessLessonsSerializer
管理员的完全访问权限:
class FullAccessLessonsSerializer(serializers.ModelSerializer):
class Meta:
model = models.Assignments
fields = ('id', 'title', 'description', 'dllink' )
未经身份验证的用户的基本访问权限:
class BasicAccessLessonsSerializer(serializers.ModelSerializer):
class Meta:
model = models.Assignments
fields = ('id', 'title', 'description')
以及学生的部分访问权限:
class PartialAccessAssignmentsSerializer(serializers.ModelSerializer):
"""A serializer for all Lessons"""
def __init__(self, *args, **kwargs):
fields = kwargs.pop('fields', None)
super(PartialAccessAssignmentsSerializer, self).__init__(*args,**kwargs)
print(self.fields.get('id'))
self.fields.pop('dllink')
class Meta:
model = models.Assignments
fields = ('id','title','description','dllink' )
我已经做了我能找到的任何事情,但我无法理解。我要么得到错误,要么删除所有dl链接。
如果你想在用户无法访问时dllink为None。请使用:
class FullAccessLessonsSerializer(serializers.ModelSerializer):
dllink = serializers.SerializerMethodField()
def get_prescription_accept(self, instance):
result = True # lookup the pair (User , Lesson) in Purchases
if result:
return instance.dllink
else:
return ''
class Meta:
model = models.Assignments
fields = ('id', 'title', 'description', 'dllink' )
如果你想从数据中弹出dllink,请使用:
class FullAccessLessonsSerializer(serializers.ModelSerializer):
def to_representation(self, instance):
data = super(FullAccessLessonsSerializer, self).to_representation(instance)
result = True # lookup the pair (User , Lesson) in Purchases
if not result:
data.pop('dllink')
return data
class Meta:
model = models.Assignments
fields = ('id', 'title', 'description', 'dllink' )