django基礎之FBV與CBV，ajax序列化補充，Form表單

時間 2019-11-26

標籤 django 基礎 fbv cbv ajax 序列補充 form 表單欄目 Python 简体版

原文原文鏈接

1、FBV與CBV

一、什麼是FBV、CBV？css

django書寫view時，支持兩種格式寫法，FBV（function bases view即函數編程），CBV（class bases view即類編程）。html

其中函數編程是本blog一直使用的編程方式，再也不討論。如下主要討論CBV方式。但這兩種方式沒有優劣，書寫可選擇任意一種使用git

二、CBV寫法應用之登錄驗證ajax

 1 from django.shortcuts import render,HttpResponse, redirect
 2 from django.views import View
 3 from django.views.decorators.csrf import csrf_exempt,csrf_protect
 4 from django.utils.decorators import method_decorator
 5 
 6 def auth(func):
 7                     def inner(request,*args,**kwargs):
 8                         if request.session.get('username'):
 9                             obj = func(request,*args,**kwargs)
10                             return obj
11                         else:
12                             return redirect('/login.html')
13                     return inner
14 
15                 
16                 # @method_decorator(auth,name='get')
17                 class IndexView(View):
18                     
19                     @method_decorator(auth)
20                     def dispatch(self, request, *args, **kwargs):
21                         if request.session.get('username'):
22                             response = super(IndexView,self).dispatch(request, *args, **kwargs)
23                             return response
24                         else:
25                             return redirect('/login.html')
26 
27                     @method_decorator(auth)
28                     def get(self,request,*args,**kwargs):
29                         return HttpResponse(request.session['username'])
30                         
31                     @method_decorator(csrf_exempt)  # 無效
32                     def post(self,request,*args,**kwargs):
33                         return HttpResponse(request.session['username'])

View Code

三、CSRF之csrf_exempt的bug處理正則表達式

 1 class IndexView(View):
 2                     
 3                         @method_decorator(csrf_exempt)
 4                         def dispatch(self, request, *args, **kwargs):
 5                             return super(LoginView,self).dispatch(request, *args, **kwargs)
 6 
 7                 
 8                         def get(self,request,*args,**kwargs):
 9                             return HttpResponse(request.session['username'])
10                             
11                         
12                         def post(self,request,*args,**kwargs):
13                             return HttpResponse(request.session['username'])

View Code

四、多實例調用數據庫

 1 from django.shortcuts import render,HttpResponse, redirect
 2 from django.views import View
 3 from django.views.decorators.csrf import csrf_exempt,csrf_protect
 4 from django.utils.decorators import method_decorator
 5 from app01 import models
 6 
 7 class AuthView(object):
 8     def dispatch(self, request, *args, **kwargs):
 9         if request.session.get('user_info'):
10             response = super(AuthView,self).dispatch(request, *args, **kwargs)
11             return response
12         else:
13             return redirect('/login.html')
14 
15 class UsersView(AuthView,View):
16 
17     def get(self,request,*args,**kwargs):
18         user_list = models.UserInfo.objects.all()
19         return render(request,'users.html',{'user_list':user_list})

View Code

2、ajax序列化補充

一、後端代碼書寫的兩種方式django

　　方式一編程

1 user_list = models.UserInfo.objects.all()
2             data = serializers.serialize("json", user_list)
3             [
4                 {"model": "app01.userinfo", "pk": 1, "fields": {"username": "\u5174\u666e", "password": "123123"}}, 
5                 {"model": "app01.userinfo", "pk": 2, "fields": {"username": "\u94f6\u79cb\u826f", "password": "666"}}
6             ]

View Code

　　方式二json

1 user_list = models.UserInfo.objects.values('id','username')
2             user_list = list(user_list)
3             data = json.dumps(user_list)
4             [
5                 {"username": "\u5174\u666e", "id": 1}, 
6                 {"username": "\u94f6\u79cb\u826f", "id": 2}
7             ]

View Code

二、對json.dumps進行定製後端

 1 import json
 2                     from datetime import date
 3                     from datetime import datetime
 4 
 5                     class JsonCustomEncoder(json.JSONEncoder):
 6                         def default(self, field):
 7                             if isinstance(field, datetime):
 8                                 return field.strftime('%Y-%m-%d %H:%M:%S')
 9                             elif isinstance(field, date):
10                                 return field.strftime('%Y-%m-%d')
11                             else:
12                                 return json.JSONEncoder.default(self, field)
13 
14 
15                     user_list = [
16                         {'id':1,'name':'alex','ctime': datetime.now()},
17                         {'id':2,'name':'eric','ctime': datetime.now()}
18                     ]
19 
20                     data = json.dumps(user_list,cls=JsonCustomEncoder)
21                     print(data)

View Code

3、Form表單（一）

一、建立From類（本質就是正則表達式的集合）

 1 from django.forms import Form
 2 from django.forms import fields
 3 from django.forms import widgets
 4 
 5 class UserForm(Form):
 6 username = fields.CharField(
 7     required=True, # 不爲空
 8     error_messages={'required':'用戶名不能爲空'}, #報錯信息
 9     widget=widgets.TextInput(attrs={'class':'form-control'}) #css樣式
10 )
11 password = fields.CharField(
12     required=True,
13     error_messages={'required': '郵箱不能爲空','invalid':'郵箱格式錯誤'},
14     widget = widgets.TextInput(attrs={'class': 'form-control'})
15 )
16 # fields.EmailField()
17 # fields.GenericIPAddressField(protocol='ipv4')
18 
19 ut_id = fields.ChoiceField(
20     choices=[],
21     widget=widgets.Select(attrs={'class':'form-control'})
22 )
23 
24 role_id = fields.MultipleChoiceField(
25     choices=[],
26     widget=widgets.SelectMultiple(attrs={'class':'form-control'})
27 )
28 
29 def __init__(self,*args,**kwargs): 
30     super(UserForm,self).__init__(*args,**kwargs) #繼承父類__init__
31     # self.fields已經有全部拷貝的字段
32     self.fields['ut_id'].choices = models.UserType.objects.values_list('id','title') #每刷新到數據庫取值
33     self.fields['role_id'].choices = models.Role.objects.values_list('id','caption')

View Code

二、生成HTML標籤

view中

form = MyForm()

html中
{{form.xx}}

 1 class AddUserView(AuthView,View):
 2     def get(self,request,*args,**kwargs):
 3         form = UserForm()
 4         return render(request,'add_user.html',{'form':form})
 5 
 6     def post(self,request,*args,**kwargs):
 7         form = UserForm(data=request.POST)
 8         # 將用戶提交的數據和UserForm中定義規則進行匹配：
 9         if form.is_valid():
10             # 把全部正確數據獲取到
11             # {'username': 'xxxxx', 'password': 'xxxxx', 'ut_id': '1'}
12             # print(form.cleaned_data)
13             # {'username': 'xxxxx', 'password': 'xxxxx', 'ut_id': '1',role_id:}
14             role_id_list = form.cleaned_data.pop('role_id') # [1,2]
15             obj = models.UserInfo.objects.create(**form.cleaned_data)
16             obj.rl.add(*role_id_list)
17             return redirect('/users.html')
18         else:
19             print(form.errors)
20             return render(request, 'add_user.html', {'form': form})

View Code

三、帶默認值的HTML標籤

view中

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

html中

 1 class EditUserView(AuthView,View):
 2     def get(self,request,pk):
 3         obj = models.UserInfo.objects.filter(id=pk).first()
 4         role_id_list = obj.rl.values_list('id')
 5         v = list(zip(*role_id_list))[0] if role_id_list else []
 6         form = UserForm(initial={'username': obj.username, 'password': obj.password, 'ut_id': obj.ut_id,'role_id':v})
 7         return render(request,'edit_user.html',{'form':form})
 8 
 9     def post(self,request,pk):
10         form = UserForm(data=request.POST)
11         if form.is_valid():
12             # # {'username': 'xxxxx', 'password': 'xxxxx', 'ut_id': '1',role_id:}
13             role_id = form.cleaned_data.pop('role_id')
14             # 用戶表更新
15             query = models.UserInfo.objects.filter(id=pk)
16             query.update(**form.cleaned_data)
17             obj = query.first()
18             obj.rl.set(role_id)
19 
20             return redirect('/users.html')
21         else:
22             print(form.errors)
23             return render(request, 'edit_user.html', {'form': form})

View Code

四、提交數據

view中

form = MyForm(data=request.POST)

if form.is_valid(): # 表單驗證
　　print(form.cleaned_data) #取表單數據
else:
　　print(form.errors) #表單錯誤信息

五、Form類以內置字段

 1 Field
 2     required=True,               是否容許爲空
 3     widget=None,                 HTML插件
 4     label=None,                  用於生成Label標籤或顯示內容
 5     initial=None,                初始值
 6     help_text='',                幫助信息(在標籤旁邊顯示)
 7     error_messages=None,         錯誤信息 {'required': '不能爲空', 'invalid': '格式錯誤'}
 8     show_hidden_initial=False,   是否在當前插件後面再加一個隱藏的且具備默認值的插件（可用於檢驗兩次輸入是否一直）
 9     validators=[],               自定義驗證規則
10     localize=False,              是否支持本地化
11     disabled=False,              是否能夠編輯
12     label_suffix=None            Label內容後綴

六、Form類以內置字段（二）

  1 CharField(Field)
  2     max_length=None,             最大長度
  3     min_length=None,             最小長度
  4     strip=True                   是否移除用戶輸入空白
  5   
  6 IntegerField(Field)
  7     max_value=None,              最大值
  8     min_value=None,              最小值
  9   
 10 FloatField(IntegerField)
 11     ...
 12   
 13 DecimalField(IntegerField)
 14     max_value=None,              最大值
 15     min_value=None,              最小值
 16     max_digits=None,             總長度
 17     decimal_places=None,         小數位長度
 18   
 19 BaseTemporalField(Field)
 20     input_formats=None          時間格式化  
 21   
 22 DateField(BaseTemporalField)    格式：2015-09-01
 23 TimeField(BaseTemporalField)    格式：11:12
 24 DateTimeField(BaseTemporalField)格式：2015-09-01 11:12
 25   
 26 DurationField(Field)            時間間隔：%d %H:%M:%S.%f
 27     ...
 28   
 29 RegexField(CharField)
 30     regex,                      自定製正則表達式
 31     max_length=None,            最大長度
 32     min_length=None,            最小長度
 33     error_message=None,         忽略，錯誤信息使用 error_messages={'invalid': '...'}
 34   
 35 EmailField(CharField)     
 36     ...
 37   
 38 FileField(Field)
 39     allow_empty_file=False     是否容許空文件
 40   
 41 ImageField(FileField)     
 42     ...
 43     注：須要PIL模塊，pip3 install Pillow
 44     以上兩個字典使用時，須要注意兩點：
 45         - form表單中 enctype="multipart/form-data"
 46         - view函數中 obj = MyForm(request.POST, request.FILES)
 47   
 48 URLField(Field)
 49     ...
 50   
 51   
 52 BooleanField(Field) 
 53     ...
 54   
 55 NullBooleanField(BooleanField)
 56     ...
 57   
 58 ChoiceField(Field)
 59     ...
 60     choices=(),                選項，如：choices = ((0,'上海'),(1,'北京'),)
 61     required=True,             是否必填
 62     widget=None,               插件，默認select插件
 63     label=None,                Label內容
 64     initial=None,              初始值
 65     help_text='',              幫助提示
 66   
 67   
 68 ModelChoiceField(ChoiceField)
 69     ...                        django.forms.models.ModelChoiceField
 70     queryset,                  # 查詢數據庫中的數據
 71     empty_label="---------",   # 默認空顯示內容
 72     to_field_name=None,        # HTML中value的值對應的字段
 73     limit_choices_to=None      # ModelForm中對queryset二次篩選
 74       
 75 ModelMultipleChoiceField(ModelChoiceField)
 76     ...                        django.forms.models.ModelMultipleChoiceField
 77   
 78   
 79       
 80 TypedChoiceField(ChoiceField)
 81     coerce = lambda val: val   對選中的值進行一次轉換
 82     empty_value= ''            空值的默認值
 83   
 84 MultipleChoiceField(ChoiceField)
 85     ...
 86   
 87 TypedMultipleChoiceField(MultipleChoiceField)
 88     coerce = lambda val: val   對選中的每個值進行一次轉換
 89     empty_value= ''            空值的默認值
 90   
 91 ComboField(Field)
 92     fields=()                  使用多個驗證，以下：即驗證最大長度20，又驗證郵箱格式
 93                                fields.ComboField(fields=[fields.CharField(max_length=20), fields.EmailField(),])
 94   
 95 MultiValueField(Field)
 96     PS: 抽象類，子類中能夠實現聚合多個字典去匹配一個值，要配合MultiWidget使用
 97   
 98 SplitDateTimeField(MultiValueField)
 99     input_date_formats=None,   格式列表：['%Y--%m--%d', '%m%d/%Y', '%m/%d/%y']
100     input_time_formats=None    格式列表：['%H:%M:%S', '%H:%M:%S.%f', '%H:%M']
101   
102 FilePathField(ChoiceField)     文件選項，目錄下文件顯示在頁面中
103     path,                      文件夾路徑
104     match=None,                正則匹配
105     recursive=False,           遞歸下面的文件夾
106     allow_files=True,          容許文件
107     allow_folders=False,       容許文件夾
108     required=True,
109     widget=None,
110     label=None,
111     initial=None,
112     help_text=''
113   
114 GenericIPAddressField
115     protocol='both',           both,ipv4,ipv6支持的IP格式
116     unpack_ipv4=False          解析ipv4地址，若是是::ffff:192.0.2.1時候，可解析爲192.0.2.1， PS：protocol必須爲both才能啓用
117   
118 SlugField(CharField)           數字，字母，下劃線，減號（連字符）
119     ...
120   
121 UUIDField(CharField)           uuid類型

七、Django內置插件：

 1 TextInput(Input)
 2 NumberInput(TextInput)
 3 EmailInput(TextInput)
 4 URLInput(TextInput)
 5 PasswordInput(TextInput)
 6 HiddenInput(TextInput)
 7 Textarea(Widget)
 8 DateInput(DateTimeBaseInput)
 9 DateTimeInput(DateTimeBaseInput)
10 TimeInput(DateTimeBaseInput)
11 CheckboxInput
12 Select
13 NullBooleanSelect
14 SelectMultiple
15 RadioSelect
16 CheckboxSelectMultiple
17 FileInput
18 ClearableFileInput
19 MultipleHiddenInput
20 SplitDateTimeWidget
21 SplitHiddenDateTimeWidget
22 SelectDateWidget

View Code

經常使用選擇插件：

 1 <strong># 單radio，值爲字符串</strong>
 2 # user = fields.CharField(
 3 #     initial=2,
 4 #     widget=widgets.RadioSelect(choices=((1,'上海'),(2,'北京'),))
 5 # )
 6   
 7 <strong># 單radio，值爲字符串</strong>
 8 # user = fields.ChoiceField(
 9 #     choices=((1, '上海'), (2, '北京'),),
10 #     initial=2,
11 #     widget=widgets.RadioSelect
12 # )
13   
14 <strong># 單select，值爲字符串</strong>
15 # user = fields.CharField(
16 #     initial=2,
17 #     widget=widgets.Select(choices=((1,'上海'),(2,'北京'),))
18 # )
19   
20 <strong># 單select，值爲字符串</strong>
21 # user = fields.ChoiceField(
22 #     choices=((1, '上海'), (2, '北京'),),
23 #     initial=2,
24 #     widget=widgets.Select
25 # )
26   
27 <strong># 多選select，值爲列表</strong>
28 # user = fields.MultipleChoiceField(
29 #     choices=((1,'上海'),(2,'北京'),),
30 #     initial=[1,],
31 #     widget=widgets.SelectMultiple
32 # )
33   
34 <strong># 單checkbox</strong>
35 # user = fields.CharField(
36 #     widget=widgets.CheckboxInput()
37 # )
38   
39 <strong># 多選checkbox,值爲列表</strong>
40 # user = fields.MultipleChoiceField(
41 #     initial=[2, ],
42 #     choices=((1, '上海'), (2, '北京'),),
43 #     widget=widgets.CheckboxSelectMultiple
44 # )

在使用選擇標籤時，須要注意choices的選項能夠從數據庫中獲取，可是因爲是靜態字段 ***獲取的值沒法實時更新***，那麼須要自定義構造方法從而達到此目的。

方式一：

 1 from django.forms import Form
 2 from django.forms import widgets
 3 from django.forms import fields
 4 from django.core.validators import RegexValidator
 5  
 6 class MyForm(Form):
 7  
 8     user = fields.ChoiceField(
 9         # choices=((1, '上海'), (2, '北京'),),
10         initial=2,
11         widget=widgets.Select
12     )
13  
14     def __init__(self, *args, **kwargs):
15         super(MyForm,self).__init__(*args, **kwargs)
16         # self.fields['user'].widget.choices = ((1, '上海'), (2, '北京'),)
17         # 或
18         self.fields['user'].widget.choices = models.Classes.objects.all().value_list('id','caption')

View Code

方式二：

使用django提供的ModelChoiceField和ModelMultipleChoiceField字段來實現

 1 from django import forms
 2 from django.forms import fields
 3 from django.forms import widgets
 4 from django.forms import models as form_model
 5 from django.core.exceptions import ValidationError
 6 from django.core.validators import RegexValidator
 7  
 8 class FInfo(forms.Form):
 9     authors = form_model.ModelMultipleChoiceField(queryset=models.NNewType.objects.all())
10     # authors = form_model.ModelChoiceField(queryset=models.NNewType.objects.all())

View Code

八、自定義規則

方式一：

1 from django.forms import Form
2 from django.forms import widgets
3 from django.forms import fields
4 from django.core.validators import RegexValidator
5  
6 class MyForm(Form):
7     user = fields.CharField(
8         validators=[RegexValidator(r'^[0-9]+$', '請輸入數字'), RegexValidator(r'^159[0-9]+$', '數字必須以159開頭')],
9     )

View Code

方式二：

 1 import re
 2 from django.forms import Form
 3 from django.forms import widgets
 4 from django.forms import fields
 5 from django.core.exceptions import ValidationError
 6  
 7  
 8 # 自定義驗證規則
 9 def mobile_validate(value):
10     mobile_re = re.compile(r'^(13[0-9]|15[012356789]|17[678]|18[0-9]|14[57])[0-9]{8}$')
11     if not mobile_re.match(value):
12         raise ValidationError('手機號碼格式錯誤')
13  
14  
15 class PublishForm(Form):
16  
17  
18     title = fields.CharField(max_length=20,
19                             min_length=5,
20                             error_messages={'required': '標題不能爲空',
21                                             'min_length': '標題最少爲5個字符',
22                                             'max_length': '標題最多爲20個字符'},
23                             widget=widgets.TextInput(attrs={'class': "form-control",
24                                                           'placeholder': '標題5-20個字符'}))
25  
26  
27     # 使用自定義驗證規則
28     phone = fields.CharField(validators=[mobile_validate, ],
29                             error_messages={'required': '手機不能爲空'},
30                             widget=widgets.TextInput(attrs={'class': "form-control",
31                                                           'placeholder': u'手機號碼'}))
32  
33     email = fields.EmailField(required=False,
34                             error_messages={'required': u'郵箱不能爲空','invalid': u'郵箱格式錯誤'},
35                             widget=widgets.TextInput(attrs={'class': "form-control", 'placeholder': u'郵箱'}))

View Code

方式三：

 1 from django import forms
 2     from django.forms import fields
 3     from django.forms import widgets
 4     from django.core.exceptions import ValidationError
 5     from django.core.validators import RegexValidator
 6  
 7     class FInfo(forms.Form):
 8         username = fields.CharField(max_length=5,
 9                                     validators=[RegexValidator(r'^[0-9]+$', 'Enter a valid extension.', 'invalid')], )
10         email = fields.EmailField()
11  
12         def clean_username(self):
13             """
14             Form中字段中定義的格式匹配完以後，執行此方法進行驗證
15             :return:
16             """
17             value = self.cleaned_data['username']
18             if "666" in value:
19                 raise ValidationError('666已經被玩爛了...', 'invalid')
20             return value

View Code

方式四：

 1 from django.forms import Form
 2 from django.forms import widgets
 3 from django.forms import fields
 4  
 5 from django.core.validators import RegexValidator
 6  
 7  
 8 ############## 自定義字段 ##############
 9 class PhoneField(fields.MultiValueField):
10     def __init__(self, *args, **kwargs):
11         # Define one message for all fields.
12         error_messages = {
13             'incomplete': 'Enter a country calling code and a phone number.',
14         }
15         # Or define a different message for each field.
16         f = (
17             fields.CharField(
18                 error_messages={'incomplete': 'Enter a country calling code.'},
19                 validators=[
20                     RegexValidator(r'^[0-9]+$', 'Enter a valid country calling code.'),
21                 ],
22             ),
23             fields.CharField(
24                 error_messages={'incomplete': 'Enter a phone number.'},
25                 validators=[RegexValidator(r'^[0-9]+$', 'Enter a valid phone number.')],
26             ),
27             fields.CharField(
28                 validators=[RegexValidator(r'^[0-9]+$', 'Enter a valid extension.')],
29                 required=False,
30             ),
31         )
32         super(PhoneField, self).__init__(error_messages=error_messages, fields=f, require_all_fields=False, *args,
33                                          **kwargs)
34  
35     def compress(self, data_list):
36         """
37         當用戶驗證都經過後，該值返回給用戶
38         :param data_list:
39         :return:
40         """
41         return data_list
42  
43 ############## 自定義插件 ##############
44 class SplitPhoneWidget(widgets.MultiWidget):
45     def __init__(self):
46         ws = (
47             widgets.TextInput(),
48             widgets.TextInput(),
49             widgets.TextInput(),
50         )
51         super(SplitPhoneWidget, self).__init__(ws)
52  
53     def decompress(self, value):
54         """
55         處理初始值，當初始值initial不是列表時，調用該方法
56         :param value:
57         :return:
58         """
59         if value:
60             return value.split(',')
61         return [None, None, None]

View Code

九、初始化數據

在Web應用程序中開發編寫功能時，時經常使用到獲取數據庫中的數據並將值初始化在HTML中的標籤上。

一、Form

 1 from django.forms import Form
 2 from django.forms import widgets
 3 from django.forms import fields
 4 from django.core.validators import RegexValidator
 5  
 6  
 7 class MyForm(Form):
 8     user = fields.CharField()
 9  
10     city = fields.ChoiceField(
11         choices=((1, '上海'), (2, '北京'),),
12         widget=widgets.Select
13     )

View Code

二、Views

 1 from django.shortcuts import render, redirect
 2 from .forms import MyForm
 3  
 4  
 5 def index(request):
 6     if request.method == "GET":
 7         values = {'user': 'root', 'city': 2}
 8         obj = MyForm(values)
 9  
10         return render(request, 'index.html', {'form': obj})
11     elif request.method == "POST":
12         return redirect('http://www.google.com')
13     else:
14         return redirect('http://www.google.com')

View Code

三、HTML

1 <form method="POST" enctype="multipart/form-data">
2     {% csrf_token %}
3     <p>{{ form.user }} {{ form.user.errors }}</p>
4     <p>{{ form.city }} {{ form.city.errors }}</p>
5  
6     <input type="submit"/>
7 </form>