Django_rest_framework_Serializer

 序列化Serializer

序列化用於對用戶請求數據進行驗證和數據進行序列化（爲了解決queryset序列化問題）。

那什麼是序列化呢？序列化就是把對象轉換成字符串，反序列化就是把字符串轉換成對象

 models部分

models.py

from django.db import models

# Create your models here.
class Group(models.Model):
    title = models.CharField(max_length=32)
    mu = models.ForeignKey(to='Menu',default=1)

class UserInfo(models.Model):
    name = models.CharField(max_length=32)
    pwd = models.CharField(max_length=32)
    group = models.ForeignKey(to="Group")

    roles = models.ManyToManyField(to="Role")
class Menu(models.Model):
    name = models.CharField(max_length=21)

class Role(models.Model):
    name = models.CharField(max_length=32)

基本操做

from rest_framework.views import APIView
from rest_framework.response import Response
from rest_framework import serializers
from app03 import models
class UsersSerializer(serializers.Serializer):
    name = serializers.CharField()  #字段名字
    pwd = serializers.CharField()

class UserView(APIView):
    def get(self,request,*args,**kwargs):
        # 方式一實現
        # user_list = models.UserInfo.objects.values('name','pwd','group__mu','group__title')
        # print(type(user_list))
        # return Response(user_list)

        # 方式二之多對象
        # user_list = models.UserInfo.objects.all()  #直接這樣查會報錯，藉助他提供的系列化
        # ser = UsersSerializer(instance=user_list,many=True) #可容許多個
        # # print(type(ser))  #<class 'rest_framework.serializers.ListSerializer'>
        # print(ser.data)  #返回的是一個有序字典

        #方式三之單對象
        user = models.UserInfo.objects.all().first()
        ser = UsersSerializer(instance=user,many=False)

        return Response(ser.data)

views.py

跨表

x1 = serializers.CharField(source='group.mu.name') 
   若是你想跨表拿你任何須要的數據，均可以用上面的這種操做，內部作判斷，若是可用內部就加括號調用了

from rest_framework.views import APIView
from rest_framework.response import Response
from rest_framework import serializers
from app03 import models
class UsersSerializer(serializers.Serializer):
    name = serializers.CharField()  #字段名字
    pwd = serializers.CharField()
    # group = serializers.CharField()  #會顯示對象
    # group_id = serializers.CharField()  #會顯示id
    x1 = serializers.CharField(source='group.mu.name')
    roles = serializers.CharField(source='roles.all') #多對多關係的這樣查出的是queryset對象

class UserView2(APIView):
    '''跨表操做'''
    def get(self,request,*args,**kwargs):

        user = models.UserInfo.objects.all()
        ser = UsersSerializer(instance=user,many=True)

        return Response(ser.data)

Views.py

複雜序列化

解決方案一

class MyCharField(serializers.CharField):

    def to_representation(self, value): ##打印的是全部的數據
        data_list = []
        for row in value:
            data_list.append(row.name)
        return data_list

class UsersSerializer(serializers.Serializer):
    name = serializers.CharField() # obj.name
    pwd = serializers.CharField()  # obj.pwd
    group_id = serializers.CharField() # obj.group_id
    xxxx = serializers.CharField(source="group.title") # obj.group.title
    x1 = serializers.CharField(source="group.mu.name") # obj.mu.name
    # x2 = serializers.CharField(source="roles.all") #  多對多關係的這樣查出的是queryset對象
    x2 = MyCharField(source="roles.all") # obj.mu.name

Views.py

解決方案二

class MyCharField(serializers.CharField):
    def to_representation(self, value):
        return {'id':value.pk, 'name':value.name}

class UsersSerializer(serializers.Serializer):
    name = serializers.CharField() # obj.name
    pwd = serializers.CharField()  # obj.pwd
    group_id = serializers.CharField() # obj.group_id
    xxxx = serializers.CharField(source="group.title") # obj.group.title
    x1 = serializers.CharField(source="group.mu.name") # obj.mu.name
    # x2 = serializers.CharField(source="roles.all") # obj.mu.name
    x2 = serializers.ListField(child=MyCharField(),source="roles.all") # obj.mu.name

Views.py

解決方案三（推薦使用）

class UsersSerializer(serializers.Serializer):
    name = serializers.CharField() # obj.name
    pwd = serializers.CharField()  # obj.pwd
    group_id = serializers.CharField() # obj.group_id
    xxxx = serializers.CharField(source="group.title") # obj.group.title
    x1 = serializers.CharField(source="group.mu.name") # obj.mu.name
    # x2 = serializers.CharField(source="roles.all") # obj.mu.name
    # x2 = serializers.ListField(child=MyCharField(),source="roles.all") # obj.mu.name
    x2 = serializers.SerializerMethodField()

    def get_x2(self,obj):  #get_字段名
        print(obj)   ##UserInfo object
        obj.roles.all()
        role_list = obj.roles.filter(id__gt=1)
        data_list = []
        for row in role_list:
            data_list.append({'pk':row.pk,'name':row.name})
        return data_list
    

Views.py

基於models

class UsersSerializer(serializers.ModelSerializer):
x1 = serializers.CharField(source='name')
group = serializers.HyperlinkedIdentityField(view_name='detail')
class Meta:
    
    model = models.UserInfo
    # fields = "__all__"
    fields = ['name','pwd','group','x1']  #自定義字段的時候注意要指定source,scource裏面的數據必須是數據庫有的數據
    depth = 1 #表示深度


class UsersView(APIView):
    def get(self,request,*args,**kwargs):
        self.dispatch
        # 方式一：
        # user_list = models.UserInfo.objects.all().values('name','pwd','group__id',"group__title")
        # return Response(user_list)

        # 方式二之多對象
        user_list = models.UserInfo.objects.all()
        # [obj1,obj2,obj3]
        ser = UsersSerializer(instance=user_list,many=True)
        return Response(ser.data)

Views.py

生成url

class UsersSerializer(serializers.ModelSerializer):  #
    group = serializers.HyperlinkedIdentityField(view_name='detail')
    class Meta:
        model = models.UserInfo
        fields = "__all__"
        fields = ['name', 'pwd','group']
        depth = 1


class UsersView(APIView):
    def get(self,request,*args,**kwargs):
        self.dispatch
        # 方式一：
        # user_list = models.UserInfo.objects.all().values('name','pwd','group__id',"group__title")
        # return Response(user_list)

        # 方式二之多對象
        user_list = models.UserInfo.objects.all()
        # [obj1,obj2,obj3]
        ser = UsersSerializer(instance=user_list,many=True,context={'request':request})
        return Response(ser.data)

views.py

from django.conf.urls import url,include
from django.contrib import admin
from app03 import views
urlpatterns = [

    url(r'^users4/', views.UserView4.as_view(), name='xxx'), #吧users4的group的值反向生成users5的url
    url(r'^users5/(?P<pk>.*)', views.UserView5.as_view(), name='detail'),  #必須叫pk
    # url(r'^users4/(?P<pk>.*)', views.UserView4.as_view(), name='detail'),
]

urls.py

全局生成url

class UsersSerializer(serializers.HyperlinkedModelSerializer): #繼承他自動生成
    class Meta:
        model = models.UserInfo
        fields = "__all__"

        # fields = ['id','name','pwd']  

class UsersView(APIView):
    def get(self,request,*args,**kwargs):
        self.dispatch
        # 方式一：
        # user_list = models.UserInfo.objects.all().values('name','pwd','group__id',"group__title")
        # return Response(user_list)

        # 方式二之多對象
        user_list = models.UserInfo.objects.all()
        # [obj1,obj2,obj3]
        ser = UsersSerializer(instance=user_list,many=True,context={'request':request})
        return Response(ser.data)

views.py

 

數據驗證

自定義

class PasswordValidator(object):
    def __init__(self, base):
        self.base = base

    def __call__(self, value):
        if value != self.base:
            message = '用戶輸入的值必須是 %s.' % self.base
            raise serializers.ValidationError(message)

    def set_context(self, serializer_field):
        """
        This hook is called by the serializer instance,
        prior to the validation call being made.
        """
        # 執行驗證以前調用,serializer_fields是當前字段對象
        pass

class UsersSerializer(serializers.Serializer):
        name = serializers.CharField(min_length=6)
        pwd = serializers.CharField(error_messages={'required': '密碼不能爲空'}, validators=[PasswordValidator('666')])

views.py

基於models

class PasswordValidator(object):
    def __init__(self, base):
        self.base = base

    def __call__(self, value):
        if value != self.base:
            message = '用戶輸入的值必須是 %s.' % self.base
            raise serializers.ValidationError(message)

    def set_context(self, serializer_field):
        """
        This hook is called by the serializer instance,
        prior to the validation call being made.
        """
        # 執行驗證以前調用,serializer_fields是當前字段對象
        pass

class UsersSerializer(serializers.ModelSerializer):
    class Meta:
        model = models.UserInfo
        fields = "__all__"
        #自定義驗證規則
        extra_kwargs = {
            'name': {'min_length': 6},
            'pwd': {'validators': [PasswordValidator(666), ]}
        }

views.py

使用

class UsersView(APIView):
    def get(self,request,*args,**kwargs):
        self.dispatch
        # 方式一：
        # user_list = models.UserInfo.objects.all().values('name','pwd','group__id',"group__title")
        # return Response(user_list)

        # 方式二之多對象
        user_list = models.UserInfo.objects.all()
        # [obj1,obj2,obj3]
        ser = UsersSerializer(instance=user_list,many=True,context={'request':request})
        return Response(ser.data)

    def post(self,request,*args,**kwargs):
        ser = UsersSerializer(data=request.data)
        if ser.is_valid():
            print(ser.validated_data)
        else:
            print(ser.errors)
        return Response('...')

views.py

鉤子函數

def validate_字段(self,validated_value):
       raise ValidationError(detail='xxxxxx')
       return validated_value
                        

 

參考or轉發

http://www.cnblogs.com/haiyan123/p/8427997.html#lable3