django基础之FBV与CBV，ajax序列化补充，Form表单

一、FBV与CBV

1、什么是FBV、CBV？

django书写view时，支持两种格式写法，FBV（function bases view即函数编程），CBV（class bases view即类编程）。

其中函数编程是本blog一直使用的编程方式，不再讨论。以下主要讨论CBV方式。但这两种方式没有优劣，书写可选择任意一种使用

2、CBV写法应用之登陆验证

 from django.shortcuts import render,HttpResponse, redirect

 from django.views import View

 from django.views.decorators.csrf import csrf_exempt,csrf_protect

 from django.utils.decorators import method_decorator

 def auth(func):

                     def inner(request,*args,**kwargs):

                         if request.session.get('username'):

                             obj = func(request,*args,**kwargs)

                             return obj

                         else:

                             return redirect('/login.html')

                     return inner

                 # @method_decorator(auth,name='get')

                 class IndexView(View):

                     @method_decorator(auth)

                     def dispatch(self, request, *args, **kwargs):

                         if request.session.get('username'):

                             response = super(IndexView,self).dispatch(request, *args, **kwargs)

                             return response

                         else:

                             return redirect('/login.html')

                     @method_decorator(auth)

                     def get(self,request,*args,**kwargs):

                         return HttpResponse(request.session['username'])

                     @method_decorator(csrf_exempt)  # 无效

                     def post(self,request,*args,**kwargs):

                         return HttpResponse(request.session['username'])

3、CSRF之csrf_exempt的bug处理

 class IndexView(View):

                         @method_decorator(csrf_exempt)

                         def dispatch(self, request, *args, **kwargs):

                             return super(LoginView,self).dispatch(request, *args, **kwargs)

                         def get(self,request,*args,**kwargs):

                             return HttpResponse(request.session['username'])

                         def post(self,request,*args,**kwargs):

                             return HttpResponse(request.session['username'])

4、多实例调用

 from django.shortcuts import render,HttpResponse, redirect

 from django.views import View

 from django.views.decorators.csrf import csrf_exempt,csrf_protect

 from django.utils.decorators import method_decorator

 from app01 import models

 class AuthView(object):

     def dispatch(self, request, *args, **kwargs):

         if request.session.get('user_info'):

             response = super(AuthView,self).dispatch(request, *args, **kwargs)

             return response

         else:

             return redirect('/login.html')

 class UsersView(AuthView,View):

     def get(self,request,*args,**kwargs):

         user_list = models.UserInfo.objects.all()

         return render(request,'users.html',{'user_list':user_list})

二、ajax序列化补充

1、后端代码书写的两种方式

　　方式一

 user_list = models.UserInfo.objects.all()

             data = serializers.serialize("json", user_list)

             [

                 {"model": "app01.userinfo", "pk": 1, "fields": {"username": "\u5174\u666e", "password": ""}},

                 {"model": "app01.userinfo", "pk": 2, "fields": {"username": "\u94f6\u79cb\u826f", "password": ""}}

             ]

　　方式二

 user_list = models.UserInfo.objects.values('id','username')

             user_list = list(user_list)

             data = json.dumps(user_list)

             [

                 {"username": "\u5174\u666e", "id": 1},

                 {"username": "\u94f6\u79cb\u826f", "id": 2}

             ]

2、对json.dumps进行定制

 import json

                     from datetime import date

                     from datetime import datetime

                     class JsonCustomEncoder(json.JSONEncoder):

                         def default(self, field):

                             if isinstance(field, datetime):

                                 return field.strftime('%Y-%m-%d %H:%M:%S')

                             elif isinstance(field, date):

                                 return field.strftime('%Y-%m-%d')

                             else:

                                 return json.JSONEncoder.default(self, field)

                     user_list = [

                         {'id':1,'name':'alex','ctime': datetime.now()},

                         {'id':2,'name':'eric','ctime': datetime.now()}

                     ]

                     data = json.dumps(user_list,cls=JsonCustomEncoder)

                     print(data)

三、Form表单（一）

1、创建From类（本质就是正则表达式的集合）

 from django.forms import Form

 from django.forms import fields

 from django.forms import widgets

 class UserForm(Form):

 username = fields.CharField(

     required=True, # 不为空

     error_messages={'required':'用户名不能为空'}, #报错信息

     widget=widgets.TextInput(attrs={'class':'form-control'}) #css样式

 )

 password = fields.CharField(

     required=True,

     error_messages={'required': '邮箱不能为空','invalid':'邮箱格式错误'},

     widget = widgets.TextInput(attrs={'class': 'form-control'})

 )

 # fields.EmailField()

 # fields.GenericIPAddressField(protocol='ipv4')

 ut_id = fields.ChoiceField(

     choices=[],

     widget=widgets.Select(attrs={'class':'form-control'})

 )

 role_id = fields.MultipleChoiceField(

     choices=[],

     widget=widgets.SelectMultiple(attrs={'class':'form-control'})

 )

 def __init__(self,*args,**kwargs):

     super(UserForm,self).__init__(*args,**kwargs) #继承父类__init__

     # self.fields已经有所有拷贝的字段

     self.fields['ut_id'].choices = models.UserType.objects.values_list('id','title') #每刷新到数据库取值

     self.fields['role_id'].choices = models.Role.objects.values_list('id','caption')

2、生成HTML标签

view中

form = MyForm()

html中
{{form.xx}}

 class AddUserView(AuthView,View):

     def get(self,request,*args,**kwargs):

         form = UserForm()

         return render(request,'add_user.html',{'form':form})

     def post(self,request,*args,**kwargs):

         form = UserForm(data=request.POST)

         # 将用户提交的数据和UserForm中定义规则进行匹配：

         if form.is_valid():

             # 把所有正确数据获取到

             # {'username': 'xxxxx', 'password': 'xxxxx', 'ut_id': '1'}

             # print(form.cleaned_data)

             # {'username': 'xxxxx', 'password': 'xxxxx', 'ut_id': '1',role_id:}

             role_id_list = form.cleaned_data.pop('role_id') # [1,2]

             obj = models.UserInfo.objects.create(**form.cleaned_data)

             obj.rl.add(*role_id_list)

             return redirect('/users.html')

         else:

             print(form.errors)

             return render(request, 'add_user.html', {'form': form})

3、带默认值的HTML标签

view中

form = MyForm(initial={'xx': xxx})

html中

 class EditUserView(AuthView,View):

     def get(self,request,pk):

         obj = models.UserInfo.objects.filter(id=pk).first()

         role_id_list = obj.rl.values_list('id')

         v = list(zip(*role_id_list))[0] if role_id_list else []

         form = UserForm(initial={'username': obj.username, 'password': obj.password, 'ut_id': obj.ut_id,'role_id':v})

         return render(request,'edit_user.html',{'form':form})

     def post(self,request,pk):

         form = UserForm(data=request.POST)

         if form.is_valid():

             # # {'username': 'xxxxx', 'password': 'xxxxx', 'ut_id': '1',role_id:}

             role_id = form.cleaned_data.pop('role_id')

             # 用户表更新

             query = models.UserInfo.objects.filter(id=pk)

             query.update(**form.cleaned_data)

             obj = query.first()

             obj.rl.set(role_id)

             return redirect('/users.html')

         else:

             print(form.errors)

             return render(request, 'edit_user.html', {'form': form})

4、提交数据

view中

form = MyForm(data=request.POST)

if form.is_valid(): # 表单验证
　　print(form.cleaned_data) #取表单数据
else:
　　print(form.errors) #表单错误信息

5、Form类之内置字段

 Field

     required=True,               是否允许为空

     widget=None,                 HTML插件

     label=None,                  用于生成Label标签或显示内容

     initial=None,                初始值

     help_text='',                帮助信息(在标签旁边显示)

     error_messages=None,         错误信息 {'required': '不能为空', 'invalid': '格式错误'}

     show_hidden_initial=False,   是否在当前插件后面再加一个隐藏的且具有默认值的插件（可用于检验两次输入是否一直）

     validators=[],               自定义验证规则

     localize=False,              是否支持本地化

     disabled=False,              是否可以编辑

     label_suffix=None            Label内容后缀

6、Form类之内置字段（二）

 CharField(Field)

     max_length=None,             最大长度

     min_length=None,             最小长度

     strip=True                   是否移除用户输入空白

 IntegerField(Field)

     max_value=None,              最大值

     min_value=None,              最小值

 FloatField(IntegerField)

     ...

 DecimalField(IntegerField)

     max_value=None,              最大值

     min_value=None,              最小值

     max_digits=None,             总长度

     decimal_places=None,         小数位长度

 BaseTemporalField(Field)

     input_formats=None          时间格式化  

 DateField(BaseTemporalField)    格式：2015-09-01

 TimeField(BaseTemporalField)    格式：11:12

 DateTimeField(BaseTemporalField)格式：2015-09-01 11:12

 DurationField(Field)            时间间隔：%d %H:%M:%S.%f

     ...

 RegexField(CharField)

     regex,                      自定制正则表达式

     max_length=None,            最大长度

     min_length=None,            最小长度

     error_message=None,         忽略，错误信息使用 error_messages={'invalid': '...'}

 EmailField(CharField)

     ...

 FileField(Field)

     allow_empty_file=False     是否允许空文件

 ImageField(FileField)

     ...

     注：需要PIL模块，pip3 install Pillow

     以上两个字典使用时，需要注意两点：

         - form表单中 enctype="multipart/form-data"

         - view函数中 obj = MyForm(request.POST, request.FILES)

 URLField(Field)

     ...

 BooleanField(Field)

     ...

 NullBooleanField(BooleanField)

     ...

 ChoiceField(Field)

     ...

     choices=(),                选项，如：choices = ((0,'上海'),(1,'北京'),)

     required=True,             是否必填

     widget=None,               插件，默认select插件

     label=None,                Label内容

     initial=None,              初始值

     help_text='',              帮助提示

 ModelChoiceField(ChoiceField)

     ...                        django.forms.models.ModelChoiceField

     queryset,                  # 查询数据库中的数据

     empty_label="---------",   # 默认空显示内容

     to_field_name=None,        # HTML中value的值对应的字段

     limit_choices_to=None      # ModelForm中对queryset二次筛选

 ModelMultipleChoiceField(ModelChoiceField)

     ...                        django.forms.models.ModelMultipleChoiceField

 TypedChoiceField(ChoiceField)

     coerce = lambda val: val   对选中的值进行一次转换

     empty_value= ''            空值的默认值

 MultipleChoiceField(ChoiceField)

     ...

 TypedMultipleChoiceField(MultipleChoiceField)

     coerce = lambda val: val   对选中的每一个值进行一次转换

     empty_value= ''            空值的默认值

 ComboField(Field)

     fields=()                  使用多个验证，如下：即验证最大长度20，又验证邮箱格式

                                fields.ComboField(fields=[fields.CharField(max_length=20), fields.EmailField(),])

 MultiValueField(Field)

     PS: 抽象类，子类中可以实现聚合多个字典去匹配一个值，要配合MultiWidget使用

 SplitDateTimeField(MultiValueField)

     input_date_formats=None,   格式列表：['%Y--%m--%d', '%m%d/%Y', '%m/%d/%y']

     input_time_formats=None    格式列表：['%H:%M:%S', '%H:%M:%S.%f', '%H:%M']

 FilePathField(ChoiceField)     文件选项，目录下文件显示在页面中

     path,                      文件夹路径

     match=None,                正则匹配

     recursive=False,           递归下面的文件夹

     allow_files=True,          允许文件

     allow_folders=False,       允许文件夹

     required=True,

     widget=None,

     label=None,

     initial=None,

     help_text=''

 GenericIPAddressField

     protocol='both',           both,ipv4,ipv6支持的IP格式

     unpack_ipv4=False          解析ipv4地址，如果是::ffff:192.0.2.1时候，可解析为192.0.2.1， PS：protocol必须为both才能启用

 SlugField(CharField)           数字，字母，下划线，减号（连字符）

     ...

 UUIDField(CharField)           uuid类型

7、Django内置插件：

 TextInput(Input)

 NumberInput(TextInput)

 EmailInput(TextInput)

 URLInput(TextInput)

 PasswordInput(TextInput)

 HiddenInput(TextInput)

 Textarea(Widget)

 DateInput(DateTimeBaseInput)

 DateTimeInput(DateTimeBaseInput)

 TimeInput(DateTimeBaseInput)

 CheckboxInput

 Select

 NullBooleanSelect

 SelectMultiple

 RadioSelect

 CheckboxSelectMultiple

 FileInput

 ClearableFileInput

 MultipleHiddenInput

 SplitDateTimeWidget

 SplitHiddenDateTimeWidget

 SelectDateWidget

常用选择插件：

 <strong># 单radio，值为字符串</strong>

 # user = fields.CharField(

 #     initial=2,

 #     widget=widgets.RadioSelect(choices=((1,'上海'),(2,'北京'),))

 # )

 <strong># 单radio，值为字符串</strong>

 # user = fields.ChoiceField(

 #     choices=((1, '上海'), (2, '北京'),),

 #     initial=2,

 #     widget=widgets.RadioSelect

 # )

 <strong># 单select，值为字符串</strong>

 # user = fields.CharField(

 #     initial=2,

 #     widget=widgets.Select(choices=((1,'上海'),(2,'北京'),))

 # )

 <strong># 单select，值为字符串</strong>

 # user = fields.ChoiceField(

 #     choices=((1, '上海'), (2, '北京'),),

 #     initial=2,

 #     widget=widgets.Select

 # )

 <strong># 多选select，值为列表</strong>

 # user = fields.MultipleChoiceField(

 #     choices=((1,'上海'),(2,'北京'),),

 #     initial=[1,],

 #     widget=widgets.SelectMultiple

 # )

 <strong># 单checkbox</strong>

 # user = fields.CharField(

 #     widget=widgets.CheckboxInput()

 # )

 <strong># 多选checkbox,值为列表</strong>

 # user = fields.MultipleChoiceField(

 #     initial=[2, ],

 #     choices=((1, '上海'), (2, '北京'),),

 #     widget=widgets.CheckboxSelectMultiple

 # )

在使用选择标签时，需要注意choices的选项可以从数据库中获取，但是由于是静态字段 ***获取的值无法实时更新***，那么需要自定义构造方法从而达到此目的。

方式一：

 from django.forms import Form

 from django.forms import widgets

 from django.forms import fields

 from django.core.validators import RegexValidator

 class MyForm(Form):

     user = fields.ChoiceField(

         # choices=((1, '上海'), (2, '北京'),),

         initial=2,

         widget=widgets.Select

     )

     def __init__(self, *args, **kwargs):

         super(MyForm,self).__init__(*args, **kwargs)

         # self.fields['user'].widget.choices = ((1, '上海'), (2, '北京'),)

         # 或

         self.fields['user'].widget.choices = models.Classes.objects.all().value_list('id','caption')

方式二：

使用django提供的ModelChoiceField和ModelMultipleChoiceField字段来实现

 from django import forms

 from django.forms import fields

 from django.forms import widgets

 from django.forms import models as form_model

 from django.core.exceptions import ValidationError

 from django.core.validators import RegexValidator

 class FInfo(forms.Form):

     authors = form_model.ModelMultipleChoiceField(queryset=models.NNewType.objects.all())

     # authors = form_model.ModelChoiceField(queryset=models.NNewType.objects.all())

8、自定义规则

方式一：

 from django.forms import Form

 from django.forms import widgets

 from django.forms import fields

 from django.core.validators import RegexValidator

 class MyForm(Form):

     user = fields.CharField(

         validators=[RegexValidator(r'^[0-9]+$', '请输入数字'), RegexValidator(r'^159[0-9]+$', '数字必须以159开头')],

     )

方式二：

 import re

 from django.forms import Form

 from django.forms import widgets

 from django.forms import fields

 from django.core.exceptions import ValidationError

 # 自定义验证规则

 def mobile_validate(value):

     mobile_re = re.compile(r'^(13[0-9]|15[012356789]|17[678]|18[0-9]|14[57])[0-9]{8}$')

     if not mobile_re.match(value):

         raise ValidationError('手机号码格式错误')

 class PublishForm(Form):

     title = fields.CharField(max_length=20,

                             min_length=5,

                             error_messages={'required': '标题不能为空',

                                             'min_length': '标题最少为5个字符',

                                             'max_length': '标题最多为20个字符'},

                             widget=widgets.TextInput(attrs={'class': "form-control",

                                                           'placeholder': '标题5-20个字符'}))

     # 使用自定义验证规则

     phone = fields.CharField(validators=[mobile_validate, ],

                             error_messages={'required': '手机不能为空'},

                             widget=widgets.TextInput(attrs={'class': "form-control",

                                                           'placeholder': u'手机号码'}))

     email = fields.EmailField(required=False,

                             error_messages={'required': u'邮箱不能为空','invalid': u'邮箱格式错误'},

                             widget=widgets.TextInput(attrs={'class': "form-control", 'placeholder': u'邮箱'}))

方式三：

 from django import forms

     from django.forms import fields

     from django.forms import widgets

     from django.core.exceptions import ValidationError

     from django.core.validators import RegexValidator

     class FInfo(forms.Form):

         username = fields.CharField(max_length=5,

                                     validators=[RegexValidator(r'^[0-9]+$', 'Enter a valid extension.', 'invalid')], )

         email = fields.EmailField()

         def clean_username(self):

             """

             Form中字段中定义的格式匹配完之后，执行此方法进行验证

             :return:

             """

             value = self.cleaned_data['username']

             if "" in value:

                 raise ValidationError('666已经被玩烂了...', 'invalid')

             return value

方式四：

 from django.forms import Form

 from django.forms import widgets

 from django.forms import fields

 from django.core.validators import RegexValidator

 ############## 自定义字段 ##############

 class PhoneField(fields.MultiValueField):

     def __init__(self, *args, **kwargs):

         # Define one message for all fields.

         error_messages = {

             'incomplete': 'Enter a country calling code and a phone number.',

         }

         # Or define a different message for each field.

         f = (

             fields.CharField(

                 error_messages={'incomplete': 'Enter a country calling code.'},

                 validators=[

                     RegexValidator(r'^[0-9]+$', 'Enter a valid country calling code.'),

                 ],

             ),

             fields.CharField(

                 error_messages={'incomplete': 'Enter a phone number.'},

                 validators=[RegexValidator(r'^[0-9]+$', 'Enter a valid phone number.')],

             ),

             fields.CharField(

                 validators=[RegexValidator(r'^[0-9]+$', 'Enter a valid extension.')],

                 required=False,

             ),

         )

         super(PhoneField, self).__init__(error_messages=error_messages, fields=f, require_all_fields=False, *args,

                                          **kwargs)

     def compress(self, data_list):

         """

         当用户验证都通过后，该值返回给用户

         :param data_list:

         :return:

         """

         return data_list

 ############## 自定义插件 ##############

 class SplitPhoneWidget(widgets.MultiWidget):

     def __init__(self):

         ws = (

             widgets.TextInput(),

             widgets.TextInput(),

             widgets.TextInput(),

         )

         super(SplitPhoneWidget, self).__init__(ws)

     def decompress(self, value):

         """

         处理初始值，当初始值initial不是列表时，调用该方法

         :param value:

         :return:

         """

         if value:

             return value.split(',')

         return [None, None, None]

9、初始化数据

在Web应用程序中开发编写功能时，时常用到获取数据库中的数据并将值初始化在HTML中的标签上。

1、Form

 from django.forms import Form

 from django.forms import widgets

 from django.forms import fields

 from django.core.validators import RegexValidator

 class MyForm(Form):

     user = fields.CharField()

     city = fields.ChoiceField(

         choices=((1, '上海'), (2, '北京'),),

         widget=widgets.Select

     )

2、Views

 from django.shortcuts import render, redirect

 from .forms import MyForm

 def index(request):

     if request.method == "GET":

         values = {'user': 'root', 'city': 2}

         obj = MyForm(values)

         return render(request, 'index.html', {'form': obj})

     elif request.method == "POST":

         return redirect('http://www.google.com')

     else:

         return redirect('http://www.google.com')

3、HTML

 <form method="POST" enctype="multipart/form-data">

     {% csrf_token %}

     <p>{{ form.user }} {{ form.user.errors }}</p>

     <p>{{ form.city }} {{ form.city.errors }}</p>

     <input type="submit"/>

 </form>