一、區域鉤子和全域鉤子

接上篇：

1、區域鉤子

在反序列化校驗中，我們不僅可以通過validators來自定義校驗函式，也可以使用鉤子函式來進行校驗，首先我們介紹區域鉤子，
區域鉤子用在單個屬性的校驗，具體寫法如下：

from rest_framework import serializers

class StudentSerializer(serializers.Serializer):
	name = serializers.CharField(max_length=4)
	age = serializers.IntegerField(max_value=80)
	class_null = serializers.CharField()
	description = serializers.CharField(allow_blank=True)
	
	# 區域鉤子如下：
	def validate_name(self,val): #函式定義規則為:validate_(要校驗屬性)
		if '777' in val:
			raise serializers.ValidationError('資料校驗未通過')
		return val

接下來我們使用postman給介面發送post請求，并得到ok回傳值：

我們接下來來看服務端回應結果：

如圖，區域鉤子生效，

2、全域鉤子

全域鉤子主要針對多個屬性進行校驗，寫法如下：

from rest_framework import serializers

class StudentSerializer(serializers.Serializer):
	name = serializers.CharField(max_length=4)
	age = serializers.IntegerField(max_value=80)
	class_null = serializers.CharField()
	description = serializers.CharField(allow_blank=True)

	# 全域鉤子如下：
	def validate(self,data): # data為post請求發送過來的有序字典資料
		# 我們可以列印下data
		print(data)
		
		name = data.get('name')
		description = data.get('description')
		if name == description:
			raise serializers.ValidationError('名字和簡介不能相等')
		return data

我們繼續使用postman向介面發送post請求：

我們接下來來看服務端回應結果：

如圖，全域鉤子生效，

執行順序：
1、執行is_valid()方法時，先校驗序列化器中的所有屬性field對應的規則
2、執行區域鉤子
3、最后執行全域鉤子

3、常用欄位和引數

常用欄位型別：

選項引數：

通用引數：

二、視圖相關

我們需要通過視圖函式來進行資料庫的操作

1、保存資料

方法一：
將校驗通過的資料提交至資料庫，我們可以通過is_valid()來進行判斷，再用orm將資料寫入資料庫：

from django.shortcuts import render,HttpResponse
from student01.models import Student
from .serializers import StudentSerializer
from django.http import JsonResponse
from django.views import View
# Create your views here.
class StudentView(View):
	def post(self,request):
		data=request.POST
		ser = StudentSerializer(data=data)
		print(ser.is_valid())
		#校驗判斷，校驗成功將資料寫入資料庫，校驗失敗回傳給錯誤提示
		if ser.is_valid():
			obj=Student.objects.create(
				**ser.validated_data
			)
			serializer=StudentSerializer(instance=obj)
			return JsonResponse(serializer.data,safe=False,json_dumps_params={'ensure_ascii':False})
		else:
			return JsonResponse({'error':'有欄位錯誤'})

使用postman來進行測驗：
我們還是使用之前的校驗規則，先發送一個非法資料：

可以看到，成功回傳了錯誤資訊，

接下來我們發送一條合法資料：

接下來我們在資料庫中驗證資料是否被成功寫入：

如圖，成功寫入資料，

方式二：
在序列器中定義create方法來保存資料：
serializers.py：

from rest_framework import serializers
from student01 import models

class StudentSerializer(serializers.Serializer):
	name = serializers.CharField(max_length=4)
	age = serializers.IntegerField(max_value=80)
	class_null = serializers.CharField()
	description = serializers.CharField(allow_blank=True)

	# 全域鉤子如下：
	def validate(self,data): # data為post請求發送過來的有序字典資料
		# 我們可以列印下data
		print(data)

		name = data.get('name')
		description = data.get('description')
		if name == description:
			raise serializers.ValidationError('名字和簡介不能相等')
		return data

	# 定義create方法
	def create(self, validated_data):
		obj=models.Student.objects.create(
			**validated_data
		)
		return obj

views.py：

from django.shortcuts import render,HttpResponse
from student01.models import Student
from .serializers import StudentSerializer
from django.http import JsonResponse
from django.views import View
# Create your views here.
class StudentView(View):
	def post(self,request):
		data=request.POST
		ser = StudentSerializer(data=data)
		print(ser.is_valid())
		#校驗判斷，校驗成功將資料寫入資料庫，校驗失敗回傳給錯誤提示
		if ser.is_valid():
			# =通過save觸發序列化器中的create方法
			instance = ser.save()
			serializer=StudentSerializer(instance=instance)
			return JsonResponse(serializer.data,safe=False,json_dumps_params={'ensure_ascii':False})
		else:
			return JsonResponse({'error':'有欄位錯誤'})

我們用postman來進行測驗：

成功拿到回傳的資料，接下來我們去資料庫驗證：

資料成功寫入！

2、更新資料

更新資料視圖檔案中需使用put方法，必須寫instance，序列化器中需定義update方法，具體寫法如下：
serializers.py:

from rest_framework import serializers
from student01 import models

class StudentSerializer(serializers.Serializer):
	name = serializers.CharField(max_length=4)
	age = serializers.IntegerField(max_value=80)
	class_null = serializers.CharField()
	description = serializers.CharField(allow_blank=True)

	# 全域鉤子如下：
	def validate(self,data): # data為post請求發送過來的有序字典資料
		# 我們可以列印下data
		print(data)

		name = data.get('name')
		description = data.get('description')
		if name == description:
			raise serializers.ValidationError('名字和簡介不能相等')
		return data

	# 定義create方法
	def create(self, validated_data):
		obj=models.Student.objects.create(
			**validated_data
		)
		return obj
	
	# 更新資料，定義update方法
	def update(self, instance, validated_data):
		print(validated_data['name'])
		instance.name=validated_data['name']
		instance.age=validated_data['age']
		instance.class_null=validated_data['class_null']
		instance.description=validated_data['description']
		instance.save()
		return instance

views.py:

from django.shortcuts import render,HttpResponse
from student01.models import Student
from .serializers import StudentSerializer
from django.http import JsonResponse
from django.views import View
from django.http.request import QueryDict
# Create your views here.
class StudentView(View):
	def post(self,request):
		data=request.POST
		ser = StudentSerializer(data=data)
		print(ser.is_valid())
		#校驗判斷，校驗成功將資料寫入資料庫，校驗失敗回傳給錯誤提示
		if ser.is_valid():
			# =通過save觸發序列化器中的create方法
			instance = ser.save()
			serializer=StudentSerializer(instance=instance)
			return JsonResponse(serializer.data,safe=False,json_dumps_params={'ensure_ascii':False})
		else:
			return JsonResponse({'error':'有欄位錯誤'})

	def put(self,request):
		ret=QueryDict(request.body)
		data={
			'id':ret.get('id'),
			'name':ret.get('name'),
			'age':ret.get('age'),
			'class_null':ret.get('class_null'),
			'description':ret.get('description')
		}
		ret1=Student.objects.get(id=data.get('id'))
		ret2=StudentSerializer(instance=ret1,data=data)
		if ret2.is_valid():
			ret2.save()
			return HttpResponse('ok')
		else:
			return JsonResponse({'error':'有欄位錯誤'})

postman傳入一組資料測驗：

資料庫中查看更新結果：

三、modelSerializer的使用

read-only：序列化時序列化出該欄位資料，反序列化時不校驗這個資料
write-only：序列化時不序列化這個欄位資料，反序列化時需客戶端傳遞這個資料進行校驗
partial：只需要校驗傳入給序列化器的資料，適用于部分資料更新

序列化器serializers.py:

from rest_framework import serializers
from student01 import models
class StudentModelSerializer(serializers.ModelSerializer):
	class Meta:
		model=models.Student
		fields='__all__'
		extra_kwargs={
			'id':{'read_only':True},
			'age':{'write_only':True}
		}

views.py:

from django.shortcuts import render
from django.http import JsonResponse
# Create your views here.
from django.views import View
from .serializers import StudentModelSerializer
from student01 import models

class StudentView(View):
	def get(self,request):
		all = models.Student.objects.all()
		serializers=StudentModelSerializer(instance=all,many=True)
		return JsonResponse(serializers.data,safe=False,json_dumps_params={'ensure_ascii':False})
	def post(self,request):
		data=request.POST
		serializers=StudentModelSerializer(data=data)
		if serializers.is_valid():
			serializers.save() #能夠自動幫我們保存資料,不用在序列化器中創建create方法

			return JsonResponse({'info':'資料保存成功！'})
		else:
			return JsonResponse({'error':'非法資料！'})

我們使用postman進行測驗：

我們在資料庫查看執行結果：

如圖，資料成功寫入

四、回應狀態碼

寫法：

from rest_framework import status

# return Response({'xx':'xxxxx'}, status=201)
return Response({'xx':'xxxxx'}, status=status.HTTP_201_CREATED)

所有狀態碼：

HTTP_100_CONTINUE = 100
HTTP_101_SWITCHING_PROTOCOLS = 101
HTTP_200_OK = 200
HTTP_201_CREATED = 201
HTTP_202_ACCEPTED = 202
HTTP_203_NON_AUTHORITATIVE_INFORMATION = 203
HTTP_204_NO_CONTENT = 204
HTTP_205_RESET_CONTENT = 205
HTTP_206_PARTIAL_CONTENT = 206
HTTP_207_MULTI_STATUS = 207
HTTP_208_ALREADY_REPORTED = 208
HTTP_226_IM_USED = 226
HTTP_300_MULTIPLE_CHOICES = 300
HTTP_301_MOVED_PERMANENTLY = 301
HTTP_302_FOUND = 302
HTTP_303_SEE_OTHER = 303
HTTP_304_NOT_MODIFIED = 304
HTTP_305_USE_PROXY = 305
HTTP_306_RESERVED = 306
HTTP_307_TEMPORARY_REDIRECT = 307
HTTP_308_PERMANENT_REDIRECT = 308
HTTP_400_BAD_REQUEST = 400
HTTP_401_UNAUTHORIZED = 401
HTTP_402_PAYMENT_REQUIRED = 402
HTTP_403_FORBIDDEN = 403
HTTP_404_NOT_FOUND = 404
HTTP_405_METHOD_NOT_ALLOWED = 405
HTTP_406_NOT_ACCEPTABLE = 406
HTTP_407_PROXY_AUTHENTICATION_REQUIRED = 407
HTTP_408_REQUEST_TIMEOUT = 408
HTTP_409_CONFLICT = 409
HTTP_410_GONE = 410
HTTP_411_LENGTH_REQUIRED = 411
HTTP_412_PRECONDITION_FAILED = 412
HTTP_413_REQUEST_ENTITY_TOO_LARGE = 413
HTTP_414_REQUEST_URI_TOO_LONG = 414
HTTP_415_UNSUPPORTED_MEDIA_TYPE = 415
HTTP_416_REQUESTED_RANGE_NOT_SATISFIABLE = 416
HTTP_417_EXPECTATION_FAILED = 417
HTTP_418_IM_A_TEAPOT = 418
HTTP_422_UNPROCESSABLE_ENTITY = 422
HTTP_423_LOCKED = 423
HTTP_424_FAILED_DEPENDENCY = 424
HTTP_426_UPGRADE_REQUIRED = 426
HTTP_428_PRECONDITION_REQUIRED = 428
HTTP_429_TOO_MANY_REQUESTS = 429
HTTP_431_REQUEST_HEADER_FIELDS_TOO_LARGE = 431
HTTP_451_UNAVAILABLE_FOR_LEGAL_REASONS = 451
HTTP_500_INTERNAL_SERVER_ERROR = 500
HTTP_501_NOT_IMPLEMENTED = 501
HTTP_502_BAD_GATEWAY = 502
HTTP_503_SERVICE_UNAVAILABLE = 503
HTTP_504_GATEWAY_TIMEOUT = 504
HTTP_505_HTTP_VERSION_NOT_SUPPORTED = 505
HTTP_506_VARIANT_ALSO_NEGOTIATES = 506
HTTP_507_INSUFFICIENT_STORAGE = 507
HTTP_508_LOOP_DETECTED = 508
HTTP_509_BANDWIDTH_LIMIT_EXCEEDED = 509
HTTP_510_NOT_EXTENDED = 510
HTTP_511_NETWORK_AUTHENTICATION_REQUIRED = 511