十三、FBV和CBV和数据序列化

FBV代表func,也就是函数。
CBV代表class,也就是类
应用场景&＃xff1a;登录验证.

FBV写法&＃xff1a;

def login(request):dic &＃61; {&＃39;tag&＃39;:None,&＃39;data&＃39;:None,&＃39;status&＃39;:True}if request.method &＃61;&＃61; &＃39;GET&＃39;:# 第一次登陆跳转到登陆return render(request,&＃39;login.html&＃39;)else:#当取不到值的时候返回falseUsername &＃61; request.POST.get(&＃39;username&＃39;,False)Password &＃61; request.POST.get(&＃39;password&＃39;,False)# print (&＃39;username:&＃39;,username)# print (&＃39;password:&＃39;,password)if not Password or not Username:ret_data &＃61; json.dumps(dic) #把字典转化为字符串&＃xff0c;然后进行返回return HttpResponse(ret_data)else:#去数据库匹匹配账户密码user_obj &＃61; models.Userinfo.objects.filter(username&＃61;Username,password&＃61;Password)if user_obj.first():#登录成功#return HttpResponse("欢迎来到我的世界")#将user_obj转化为json格式的数据。json_data &＃61; serializers.serialize(&＃39;json&＃39;,user_obj)dic[&＃39;data&＃39;] &＃61; json_data# 设置session内部的字典内容request.session[&＃39;is_login&＃39;] &＃61; user_obj.first().namerequest.session[&＃39;username&＃39;] &＃61; Usernamereturn HttpResponse(json.dumps(dic))#登录成功就跳转到后台页面#return redirect("/page")#return redirect(&＃39;/session&＃39;)else:return HttpResponse("账号密码错误")


CBV写法&＃xff1a;

例如我们正常登类为index,验证类为auth,登录类为Login,我们用index类&＃xff0c;继承auth类&＃xff0c;就可以实现验证登录&＃xff0c;然后验证失败就调用Login类&＃xff0c;

逻辑view写法&＃xff1a;
from django.views import View
from django.core import serializersclass Login(View):def get(self,request):#第一次访问return render(request,&＃39;login.html&＃39;)def post(self,request):dic &＃61; {&＃39;tag&＃39;: None, &＃39;data&＃39;: None, &＃39;status&＃39;: True}Username &＃61; request.POST.get(&＃39;username&＃39;, False)Password &＃61; request.POST.get(&＃39;password&＃39;, False)if not Password or not Username:ret_data &＃61; json.dumps(dic) # 把字典转化为字符串&＃xff0c;然后进行返回return HttpResponse(ret_data)else:# 去数据库匹匹配账户密码user_obj &＃61; models.Userinfo.objects.filter(username&＃61;Username, password&＃61;Password)if user_obj.first():#给session字典赋值request.session[&＃39;login&＃39;] &＃61; user_obj.first().namereturn redirect(&＃39;/index_demo&＃39;)else:return HttpResponse("账号密码错误")
class Auth(View):def dispatch(self, request, *args, **kwargs):#有session固定写法,获取Login登录时候的session的key值if request.session.get(&＃39;login&＃39;):response &＃61; super(Auth,self).dispatch(request, *args, **kwargs)return responseelse:return redirect(&＃39;/login_demo&＃39;)
#继承Auth ,Index就不能直接访问了&＃xff0c;需要登录验证
class Index(Auth):def get(self,request):return HttpResponse(&＃39;Index&＃39;)


路由url.py中添加&＃xff1a;

url(r&＃39;^login_demo&＃39;, views.Login.as_view()),
url(r&＃39;^index_demo&＃39;, views.Index.as_view()),


测试&＃xff1a;
此时启动访问http://127.0.0.1:8080/index_demo&＃xff0c;因为没有session,所以不能直接访问&＃xff0c;会跳转到login登录界面&＃xff0c;登录以后才能直接访问

序列化&＃xff1a;

所谓序列化就是对数据格式转化为json格式
由于json.dumps 不能对 QuerySet 类型进行处理&＃xff0c; 所以 要使用 serializers.serialize
我们导入serialize 库&＃xff0c;然后再操作数据

from django.core import serializersif user_obj.first():#登录成功#return HttpResponse("欢迎来到我的世界")#将user_obj转化为json格式的数据。json_data &＃61; serializers.serialize(&＃39;json&＃39;,user_obj)dic[&＃39;data&＃39;] &＃61; json_data


结果&＃xff1a;

如果操作的数据类型是date,datetime的话&＃xff0c;那么就需要帮它们转换一下&＃xff0c;在json.dumps 的命令中 可以多增加一个参数&＃xff0c;cls&＃61;一个类&＃xff0c;这个类继承 json.JSONEncoder,如下
isinstance() 函数来判断一个对象是否是一个已知的类型&＃xff0c;类似 type()。

from datetime import datetime
#!/usr/bin/env python
import json
from datetime import datetime
class JsonCustomEncoder(json.JSONEncoder):def default(self, field):if isinstance(field, datetime):return field.strftime(&＃39;%Y-%m-%d %H:%M:%S&＃39;)elif isinstance(field, date):return field.strftime(&＃39;%Y-%m-%d&＃39;)else:return json.JSONEncoder.default(self, field)user_list &＃61; [{&＃39;id&＃39;: 1, &＃39;name&＃39;: &＃39;alex&＃39;, &＃39;ctime&＃39;: datetime.now()},{&＃39;id&＃39;: 2, &＃39;name&＃39;: &＃39;eric&＃39;, &＃39;ctime&＃39;: datetime.now()}
]data &＃61; json.dumps(user_list, cls&＃61;JsonCustomEncoder)
print(data)


结果&＃xff1a;

[root&＃64;master config]# python cvb.py
[{"ctime": "2018-12-30 13:37:29", "id": 1, "name": "alex"}, {"ctime": "2018-12-30 13:37:29", "id": 2, "name": "eric"}]


这样就可以帮助我们处理 datetime,date类型了&＃xff0c;其他类型&＃xff0c;当然也可以&＃xff0c;修改类里面就ok