Django 10 表单

表单的使用流程

1. 定义

1. terminal 输入 django-admin startapp the_14回车

2. tutorial子文件夹 settings.py INSTALLED_APPS 中括号添加 "the_14",

INSTALLED_APPS = ['django.contrib.admin','django.contrib.auth','django.contrib.contenttypes','django.contrib.sessions','django.contrib.messages','django.contrib.staticfiles',"the_3","the_5","the_6","the_7","the_8","the_9","the_10","the_12","the_13","the_14",
]

3. tutorial子文件夹 urls.py

from django.contrib import admin
from django.urls import path,include
import the_3.urlsurlpatterns = [path('admin/', admin.site.urls),path('the_3/', include('the_3.urls')),path('the_4/', include('the_4.urls')),path('the_5/', include('the_5.urls')),path('the_7/', include('the_7.urls')),path('the_10/', include('the_10.urls')),path('the_12/', include('the_12.urls')),path('the_13/', include('the_13.urls')),path('the_14/', include('the_14.urls')),
]

4. the_14 子文件夹添加 urls.py

from django.urls import path
from .views import hellourlpatterns = [path('hello/', hello),
]

5. the_14\views.py

from django.http import HttpResponse
from django.shortcuts import render# Create your views here.def hello(request):return HttpResponse('hello world')

6. 运行tutorial, 点击 http://127.0.0.1:8000/，浏览器地址栏 127.0.0.1:8000/the_14/hello/ 刷新

7. 定义表单，在 the_14文件夹创建 forms.py文件

from django import formsclass NameForm(forms.Form):your_name = forms.CharField(label='你的名字', max_length=10)

8. the_14\views.py

from django.http import HttpResponse
from django.shortcuts import render# Create your views here.def hello(request):return render(request, 'the_14/hello.html')

9. templates创建the_14子文件夹，再在 the_14子文件夹创建 hello.html

<!DOCTYPE html>
<html lang="en">
<head><meta charset="UTF-8"><title>Title</title>
</head>
<body><h1>我是表单页面</h1>
</body>
</html>

10. 运行tutorial, 点击 http://127.0.0.1:8000/，浏览器地址栏 127.0.0.1:8000/the_14/hello/ 刷新

11. 我想把form的内容渲染到前端去，首先the_14\views.py 写入

from django.http import HttpResponse
from django.shortcuts import render
from .forms import NameForm# Create your views here.def hello(request):form = NameForm()return render(request, 'the_14/hello.html', {'myform':form})

其次，在 template\the_14\hello.html

<!DOCTYPE html>
<html lang="en">
<head><meta charset="UTF-8"><title>Title</title>
</head>
<body><h1>我是表单页面</h1>{{ myform }}
</body>
</html>

刷新网页

注意：这里是没办法提交的，如果想提交，需要嵌套一个form表单

<body><h1>我是表单页面</h1><form action="">{{ myform }}</form>
</body>

表单的绑定与非绑定

绑定就是说表单里面有值了，非绑定就是表单里面还没有值

表单提交了就是有值，没有提交或者提交错误就是拿不到值，拿不到值就是非绑定的状态。

怎么证明表单里面没有值

the_14\views.py

from django.http import HttpResponse
from django.shortcuts import render
from .forms import NameForm# Create your views here.def hello(request):form = NameForm()import pdbpdb.set_trace()return render(request, 'the_14/hello.html', {'myform':form})

重新运行，刷新网页， terminal 输入 p form 回车

-> return render(request, 'the_14/hello.html', {'myform':form})
(Pdb) p form
<NameForm bound=False, valid=Unknown, fields=(your_name)>

bound=False 就是非绑定的状态

terminal 再输入 p dir(form) 回车

(Pdb) p dir(form)
['__class__', '__delattr__', '__dict__', '__dir__', '__doc__', '__eq__', '__format__', '__ge__', '__getattribute__', '__getitem__', '__getstate__', '__gt__', '__hash__', '__html__', '__init__', '__init_subclass__', '__iter__', '__le__', '__lt__', '__module__', '__ne__', '__new__', '__reduce__', '__reduce_ex__', '__repr__', '__setattr__', '__sizeof__', '__str__', '__subclasshook__', '__weakref__', '_bound_fields_cache', '_clean_fields', '_clean_form', '_errors', '_html_output', '_post_clean', 'add_error', 'add_initial_prefix', 'add_prefix', 'as_p', 'as_table', 'as_ul', 'auto_id', 'base_fields', 'changed_data', 'clean', 'data', 'declared_fields', 'default_renderer', 'empty_permitted', 'error_class', 'errors', 'field_order', 'fields', 'files', 'full_clean', 'get_initial_for_field', 'has_changed', 'has_error', 'hidden_fields', 'initial', 'is_bound', 'is_multipart', 'is_valid', 'label_suffix', 'media', 'non_field_errors', 'order_fields', 'prefix', 'renderer', 'use_required_attribute', 'visible_fields']

is_bound 判断是否绑定的状态

terminal 输入 p form.is_bound回车， False指的是非绑定状态

(Pdb) p form.is_bound
False

terminal 输入 c回车，结束调试

(Pdb) c
[07/Jan/2024 19:10:13] "GET /the_14/hello/ HTTP/1.1" 200 344

2.渲染

渲染表单到模板

{{ form.as_table }}、{{ form.as_table }}、{{ form.as_p }}、{{ form.as_ul }}

{{ form.attr }}

the_14\hello.html

<!DOCTYPE html>
<html lang="en">
<head><meta charset="UTF-8"><title>Title</title>
</head>
<body><h1>我是表单页面</h1><form action="" method="post">账号：{{ myform.your_name }}<input type="submit" value="上传"></form>
</body>
</html>

表单验证

字段验证
基于cleaned_data的类方法： clean_<fieldname>()
基于cleaned_data的类方法：clean()

表单使用：其实是包含的两个请求的

第一个请求， get请求，这个请求可以拿到网页，展示页面

第二个请求， post请求，这个请求主要是提供数据给后台，注意：需要声明请求的url

templates\the_14\hello.html

<!DOCTYPE html>
<html lang="en">
<head><meta charset="UTF-8"><title>Title</title>
</head>
<body><h1>我是表单页面</h1><form action="{% url 'form_hello' %}" method="post">账号：{{ myform.your_name }}<input type="submit" value="上传"></form>
</body>
</html>

the_14\urls.py

from django.urls import path
from .views import hellourlpatterns = [path('hello/', hello, name='form_hello'),
]

the_14\views.py

from django.http import HttpResponse
from django.shortcuts import render
from .forms import NameForm# Create your views here.def hello(request):form = NameForm()# import pdb# pdb.set_trace()print(form.is_bound)return render(request, 'the_14/hello.html', {'myform':form})

刷新网页，输入名字panda, 点击上传，可以看到有两个False, 执行了两次。

False
[07/Jan/2024 20:56:07] "GET /the_14/hello/ HTTP/1.1" 200 352
False
[07/Jan/2024 20:56:13] "POST /the_14/hello/ HTTP/1.1" 200 352

第二次优化

the_14\views.py

from Scripts.bottle import view
from django.http import HttpResponse
from django.shortcuts import render
from .forms import NameForm# Create your views here.# def hello(request):
#     request.method = 'GET'
#     form = NameForm()
#     # import pdb
#     # pdb.set_trace()
#     print(form.is_bound)
#     return render(request, 'the_14/hello.html', {'myform':form})class Hello(view):def get(self, request):form = NameForm()return render(request, 'the_14/hello.html', {'myform': form})def post(self,request):form = NameForm(request.POST)return render(request, 'the_14/hello.html', {'myform': form,'post':True})

the_14\urls.py

from django.urls import path
from .views import Hellourlpatterns = [# path('hello/', hello, name='form_hello'),path('hello/', Hello.as_view(), name='form_hello'),
]

刷新网页，输入 panda提交，浏览器页面会出来这里是post返回的内容。

字段验证

输入的字段受 max_length的长度限制

基于cleaned_data的类方法： clean_<fieldname>()

def post(self,request): form = NameForm(request.POST) # form.data # 属于原始数据 if form.is_valid(): # 是否校验过 print(form.cleaned_data) # 校验之后的数据，干净的数据 return render(request, 'the_14/hello.html', {'myform': form,'post':True})

the_14\forms.py

from django import formsclass NameForm(forms.Form):your_name = forms.CharField(label='你的名字', max_length=10)def clean_your_name(self):  # 专门校验your_nameyour_name = self.cleaned_data['your_name']if your_name.startswith('fuck'):raise forms.ValidationError('不能带脏字哟！')  # 不通过就主动抛出错误return your_name

the_14\views.py

from Scripts.bottle import view
from django.http import HttpResponse
from django.shortcuts import render
from .forms import NameForm# Create your views here.# def hello(request):
#     request.method = 'GET'
#     form = NameForm()
#     # import pdb
#     # pdb.set_trace()
#     print(form.is_bound)
#     return render(request, 'the_14/hello.html', {'myform':form})class Hello(view):def get(self, request):form = NameForm()return render(request, 'the_14/hello.html', {'myform': form})def post(self,request):form = NameForm(request.POST)# form.data # 属于原始数据if form.is_valid(): # 是否校验过print(form.cleaned_data) # 校验之后的数据， 干净的数据else:print(form.errors)return render(request, 'the_14/hello.html', {'myform': form,'post':True})

刷新浏览器，输入 fuck_panda, 上传就会出现以下内容

基于cleaned_data的类方法：clean()

如果有多个字段，应该怎么校验

the_14 \forms.py 添加 your_title = forms.CharField(label='你的头衔', max_length=10)

from django import formsclass NameForm(forms.Form):your_name = forms.CharField(label='你的名字', max_length=10)your_title = forms.CharField(label='你的头衔', max_length=10)def clean_your_name(self):  # 专门校验your_nameyour_name = self.cleaned_data['your_name']if your_name.startswith('fuck'):raise forms.ValidationError('不能带脏字哟！')  # 不通过就主动抛出错误return your_name

templates\the_14\hello.html

<!DOCTYPE html>
<html lang="en">
<head><meta charset="UTF-8"><title>Title</title>
</head>
<body><h1>我是表单页面</h1><form action="{% url 'form_hello' %}" method="post">账号：{{ myform.your_name }} <br>头衔：{{ myform.your_title }} <br><input type="submit" value="上传"></form>{% if post %}<div>这里是post返回的内容</div>{% endif %}
</body>
</html>

刷新网页

templates\the_14\hello.html 也可以只写 {{ myform }}

    <form action="{% url 'form_hello' %}" method="post">
{#        账号：{{ myform.your_name }} <br>#}
{#        头衔：{{ myform.your_title }} <br>#}{{ myform }}<input type="submit" value="上传"></form>

刷新网页

the_14\forms.py

from django import formsclass NameForm(forms.Form):your_name = forms.CharField(label='你的名字', max_length=10)your_title = forms.CharField(label='你的头衔', max_length=10)def clean_your_name(self):  # 专门校验your_nameyour_name = self.cleaned_data.get('your_name', '')if your_name.startswith('fuck'):raise forms.ValidationError('不能带脏字哟！')  # 不通过就主动抛出错误return your_name"""如果名字以pd开头，头衔必须使用金牌     """def clean(self):name = self.cleaned_data.get('your_name','')title = self.cleaned_data.get('your_title', '')if name.startswith('pd_') and title != "金牌":raise forms.ValidationError('如果名字以pd开头，头衔必须使用金牌')

刷新网页，输入 fuck_panda , pfshjln 上传

如果使用['your_name']自定义的验证之后，还会进行clean()的联合校验，但是自定义没有通过，数据是不会填充到clean里面来的，所以
self.cleaned_data['your_name'] 是取不到值的

属性验证

the_14\forms.py

from django import forms
from django.core.validators import MinLengthValidatorclass NameForm(forms.Form):your_name = forms.CharField(label='你的名字', max_length=10,validators=[MinLengthValidator(3,'你的长度应该要大于3个')])your_title = forms.CharField(label='你的头衔', max_length=10)

刷新网页，填入 1， unknown, 点击上传，浏览器返回

自定义验证器 - （from django.core import validators）

the_14\forms.py

from django import forms
from django.core.validators import MinLengthValidatordef my_validator(value):if len(value) < 4:raise forms.ValidationError('你写少了，赶紧修改')class NameForm(forms.Form):# your_name = forms.CharField(label='你的名字', max_length=10,validators=[MinLengthValidator(3,'你的长度应该要大于3个')])your_name = forms.CharField(label='你的名字', max_length=10, validators=[my_validator])your_title = forms.CharField(label='你的头衔', max_length=10)

刷新网页，输入 111， unknown 点击上传