django之form功能

Django的Form主要具有一下几大功能：

• 生成HTML标签
• 验证用户数据（显示错误信息）
• HTML Form提交保留上次提交数据
• 初始化页面显示内容

1、form的创建：

示例：

class LoginForm(Form):
# 正则验证：不能为空，6-18
username=fields.CharField(
max_length=18,
min_length=6,
required=True,
error_messages={
'required':'用户名不能为空',
'min_length':'用户名最少需要6个字符',
'max_length':'用户名最多可用18个字符',
})
# 正则验证: 不能为空，16+
password = fields.CharField(
min_length=10,
required=True,
error_messages={
'required': '密码不能为空',
'min_length': '密码最少需要10个字符',
}
)

在views.py函数内部的处理：

from django.shortcuts import render,HttpResponse,redirect
from django.forms import Form
from django.forms import fields
class LoginForm(Form):
# 正则验证：不能为空，6-18
username=fields.CharField(
max_length=18,
min_length=6,
required=True,
error_messages={
'required':'用户名不能为空',
'min_length':'用户名最少需要6个字符',
'max_length':'用户名最多可用18个字符',
})
# 正则验证: 不能为空，16+
password = fields.CharField(
min_length=10,
required=True,
error_messages={
'required': '密码不能为空',
'min_length': '密码最少需要10个字符',
}
)
def login(request):
if request.method == "GET":
return render(request,'login.html')
else:
obj = LoginForm(request.POST)
if obj.is_valid():
# 用户输入格式正确
print(obj.cleaned_data) # 字典类型
return redirect('http://www.cnblogs.com/xuyuanyuan123/')
else:
# 用户输入格式错误
return render(request,'login.html',{'obj':obj})

url.py

from app01 import views

urlpatterns = [
url(r'^admin/', admin.site.urls),
url(r'^login.html$', views.login),

]

login.html

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

View Code

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
# )

示例：

select的多种写法：

a、单选

# 下拉框的方法1：
# cls_id = fields.IntegerField(
#     widget=widgets.Select(choices=[(1,'上海'),(2,'北京')]))
# 下拉框的方法2：
# cls_id = fields.CharField(
#     widget=widgets.Select(choices=[(1,'昌平区'),(2,'海淀区'),(3,'朝阳区')]))
# 下拉框的方法3：
# cls_id = fields.ChoiceField(
#     choices=[(1,'10号线'),(2,'8号线'),(3,'5号线')]
# )

b、多选

#多选下拉框（有自定义属性）
# xdb = fields.MultipleChoiceField(
#     choices=[(1, '朝阳区'), (2, '海淀区'), (3, '昌平区')],
#     widget=widgets.SelectMultiple(attrs={'class':'c1'}) #后面参数是定制属性
# )
#单选checkbox
# xdb = fields.CharField(
#     widget=widgets.CheckboxInput()
# )
#多选checkbox （多个checkbox,二选一）
# xdb = fields.MultipleChoiceField(
#     initial=[2, ],
#     choices=((1, '上海'), (2, '北京'),),
#     widget=widgets.CheckboxSelectMultiple
# )

#多个选项Radio （互斥 三选一）
# xdb =  fields.ChoiceField(
#     choices=((1, '上海'), (2, '北京'),(3, '北京1'),),
#     initial=2,
#     widget=widgets.RadioSelect
# )

 

用form实现验证的功能：（一对一、一对多、多对多）

1、单表的操作：（一对一）====>班级表

首先建立一个新的目录：（该结构如下）

首先先建立表格，在models.py内写入：

from django.db import models

class Classes(models.Model):
cname=models.CharField(max_length=32)

class Student(models.Model):
sname=models.CharField(max_length=32)
email=models.CharField(max_length=32)
age=models.IntegerField(max_length=16)
cls=models.ForeignKey('Classes')

class Teacher(models.Model):
tname=models.CharField(max_length=32)
c2t=models.ManyToManyField('Classes')
# c2t=models.ManyToManyField('Classes')相当于建立的第四张关系表

　urls.py

from django.conf.urls import url
from django.contrib import admin
from app01 import views

urlpatterns = [
url(r'^admin/', admin.site.urls),
# =======班级表:单表操作=====
url(r'^classes.html$',views.classes),
url(r'^add_class.html$',views.add_class),
url(r'^edit_class/(\d+)',views.edit_class),
url(r'^del_class/(\d+)',views.del_class),

# ======班级表和学生表操作：一对多操作=====
url(r'^student.html$',views.student),
url(r'^add_student.html$',views.add_student),
url(r'^edit_student/(\d+)',views.edit_student),
url(r'^del_student/(\d+)',views.del_student),

# ===========班级表和老师表操作：多对多操作=========
url(r'^teacher.html$',views.teacher),
url(r'^add_teacher.html$',views.add_teacher),
url(r'^edit_teacher/(\d+)',views.edit_teacher),
url(r'^del_teacher/(\d+)',views.del_teacher),
]

views.py

from django.shortcuts import render,redirect,HttpResponse
from django.forms import Form
from app01 import models
from django.forms import fields
from django.forms import widgets
# =========================班级表操作=========================
class ClassForm(Form):
cname=fields.RegexField('老男孩\d+')

def classes(request):
cls_list=models.Classes.objects.all()
return render(request,"classes.html",{"cls_list":cls_list})

def add_class(request):
if request.method=="GET":
obj=ClassForm()
return render(request,"add_class.html",{"obj":obj})
else:
obj=ClassForm(request.POST)
print(obj)
if obj.is_valid():
# obj.cleaned_data是字典格式
# print(obj.cleaned_data)
#如果用户输入的信息无误的话，则需要在数据库中插入用户输入的数据
models.Classes.objects.create(**obj.cleaned_data)
return redirect("/classes.html")
return render(request,'add_class.html',{'obj':obj})

def edit_class(request,nid):
if request.method=="GET":
res=models.Classes.objects.filter(id=nid).first()
# 让页面显示初始值
# obj = ClassForm(data={'cname': '老男孩3期'})#这里面含有验证规则，有错误信息显示
obj=ClassForm(initial={'cname':res.cname})
return render(request,"edit_class.html",{'nid':nid,'obj':obj})
else:
obj=ClassForm(request.POST)
if obj.is_valid():
models.Classes.objects.filter(id=nid).update(**obj.cleaned_data)
return redirect("/classes.html")
return render(request,"edit_class.html",{'nid':nid,'obj':obj})

def del_class(request,nid):
models.Classes.objects.filter(id=nid).delete()
return redirect("/classes.html")

classes.html

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
</head>
<body>
<h1>班级列表</h1>
<div>
<a href="/add_class.html">添加班级</a>
</div>
<ul>
{% for i in cls_list %}
<li>
{{ i.cname }}|<a href="/edit_class/{{ i.id }}">编辑</a>|<a href="/del_class/{{ i.id }}">删除</a>
</li>
{% endfor %}
</ul>
</body>
</html>

add_class.html

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
</head>
<body>
<h1>添加班级</h1>
<form method="POST" action="/add_class.html">
{% csrf_token %}
<p>
{{ obj.cname }}{{ obj.errors.cname.0 }}
</p>
<p>
<input type="submit" value="提交">
</p>
</form>
</body>
</html>

edit_class.html

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
</head>
<body>
<h1>编辑班级</h1>
<form action="/edit_class/{{ nid }}" method="POST">
{% csrf_token %}
<p>
{{ obj.cname }}{{ obj.errors.cname.0 }}
</p>
<input type="submit" value="提交">

</form>
</body>
</html>

页面展示效果图：

 

2、form验证操作：（一对多）====>班级表和学生表操作：

views.py

from django.shortcuts import render,redirect,HttpResponse
from django.forms import Form
from app01 import models
from django.forms import fields
from django.forms import widgets
# ================一对多：学生表操作======
class StudentForm(Form):
sname=fields.CharField(
min_length=2,
max_length=6,
widget=widgets.TextInput(attrs={'class':'form-control'})#给标签的input框加一个样式
)
email=fields.EmailField(
widget=widgets.TextInput(attrs={'class': 'form-control'})
)
age=fields.IntegerField(
min_value=18,
max_value=30,
widget=widgets.TextInput(attrs={'class': 'form-control'})
)
# 下拉框的方法1：
# cls_id = fields.IntegerField(
#     widget=widgets.Select(choices=[(1,'上海'),(2,'北京')]))
# 下拉框的方法2：
# cls_id = fields.CharField(
#     widget=widgets.Select(choices=[(1,'昌平区'),(2,'海淀区'),(3,'朝阳区')]))
# 下拉框的方法3：
# cls_id = fields.ChoiceField(
#     choices=[(1,'10号线'),(2,'8号线'),(3,'5号线')]
# )
cls_id=fields.IntegerField(
# widget=widgets.Select(choices=[(1,'上海'),(2,'北京')])
#在这里需要用列表套元祖的方式，所以用values_list
widget=widgets.Select(choices=models.Classes.objects.values_list('id', 'cname'),attrs={'class': 'form-control'})
)

def student(request):
s_list=models.Student.objects.all()
return render(request,"student.html",{"s_list":s_list})

def add_student(request):
if request.method=="GET":
obj=StudentForm()
return render(request,"add_student.html",{'obj':obj})
else:
obj=StudentForm(request.POST)
if obj.is_valid():
models.Student.objects.create(**obj.cleaned_data)
return redirect("/student.html")
else:
return render(request, "add_student.html", {'obj': obj})

def edit_student(request,nid):
if request.method=="GET":
ret=models.Student.objects.filter(id=nid).values("sname","email","age","cls_id").first()
obj=StudentForm(initial=ret)
return render(request,"edit_student.html",{'nid':nid,'obj':obj})
else:
obj=StudentForm(request.POST)
if obj.is_valid():
models.Student.objects.filter(id=nid).update(**obj.cleaned_data)
return redirect("/student.html")
else:
return render(request, "edit_student.html", {'nid': nid,'obj':obj})

def del_student(request,nid):
models.Student.objects.filter(id=nid).delete()
return redirect("/student.html")

student.html

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
</head>
<body>
<h1>学生列表</h1>
<a href="/add_student.html">添加学生</a>
<ul>
{% for i in s_list %}
<li>
{{ i.sname }}/{{ i.email }}/{{ i.age }}/{{ i.cls_id }}/{{ i.cls.title }}|<a href="/edit_student/{{ i.id }}">编辑</a>|<a href="/del_student/{{ i.id }}">删除</a>
</li>
{% endfor %}
</ul>

</body>
</html>

add_student.html

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
</head>
<body>
<h1>添加学生</h1>
<form action="/add_student.html" method="POST">
{% csrf_token %}
<p>
{{ obj.sname }}{{ obj.errors.sname.0 }}
</p>
<p>
{{ obj.email }}{{ obj.errors.email.0 }}
</p>
<p>
{{ obj.age }}{{ obj.errors.age.0 }}
</p>
<p>
{{ obj.cls_id }}{{ obj.errors.cls_id.0 }}
</p>
<input type="submit" value="提交" />
</form>

</body>
</html>

edit_student.html

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
</head>
<body>
<div style="width: 500px;margin: 0 auto;">
<form class="form-horizontal" method="POST" action="/edit_student/{{ nid }}/">
{% csrf_token %}
<div class="form-group">
<label class="col-sm-2 control-label">姓名：</label>

<div class="col-sm-10">
{{ obj.sname }}{{ obj.errors.sname.0 }}
</div>
</div>
<div class="form-group">
<label class="col-sm-2 control-label">邮箱：</label>

<div class="col-sm-10">
{{ obj.email }}{{ obj.errors.email.0 }}
</div>
</div>
<div class="form-group">
<label class="col-sm-2 control-label">年龄：</label>

<div class="col-sm-10">
{{ obj.age }}{{ obj.errors.age.0 }}
</div>
</div>
<div class="form-group">
<label class="col-sm-2 control-label">班级：</label>

<div class="col-sm-10">
{{ obj.cls_id }}{{ obj.errors.cls_id.0 }}
</div>
</div>
<div class="form-group">
<div class="col-sm-offset-2 col-sm-10">
<input type="submit" class="btn btn-default" value="提交" />
</div>
</div>
</form>
</div>
</body>
</html>

页面效果图展现：

 

3、form表单验证：班级表和老师表（多对多的关系）

views.py

from django.shortcuts import render,redirect,HttpResponse
from django.forms import Form
from app01 import models
from django.forms import fields
from django.forms import widgets
# ============多对多：老师表操作===============
class TeacherForm(Form):
tname=fields.CharField(min_length=2)
cls_name=fields.MultipleChoiceField(
choices=models.Classes.objects.values_list("id","cname"),
widget=widgets.SelectMultiple
)

def teacher(request):
t_list=models.Teacher.objects.all()
return render(request,"teacher.html",{'t_list':t_list})

def add_teacher(request):
if request.method=="GET":
obj=TeacherForm()
return render(request,"add_teacher.html",{'obj':obj})
else:
obj=TeacherForm(request.POST)
if obj.is_valid():
print(obj.cleaned_data)
cls_name=obj.cleaned_data.pop("cls_name")
row=models.Teacher.objects.create(**obj.cleaned_data)
# print(cls_name)
print(row)
row.c2t.add(*cls_name)
return redirect('/teacher.html')
return render(request, "add_teacher.html", {'obj': obj})

def edit_teacher(request,nid):
if request.method=="GET":
res=models.Teacher.objects.filter(id=nid).first()#取到老师的id和老师的姓名
#需要取到班级的id
class_id=res.c2t.values_list("id")
# print(class_id)#是一个字符串
# cid_list=[]
cid_list=list(zip(*class_id))[0] if list(zip(*class_id)) else []
# 使用三元表达式cid_list=list(zip(*class_id))[0] if list(zip(*class_id)) else []
obj=TeacherForm(initial={'tname':res.tname,'cid_list':cid_list})
return render(request,"edit_teacher.html",{'nid':nid,'obj':obj})
else:
obj=TeacherForm(request.POST)
if obj.is_valid():
# print(obj.cleaned_data)#{'tname': 'alex', 'cls_name': ['1', '2']}
cls_name=obj.cleaned_data.pop("cls_name")
print(cls_name)
ret=models.Teacher.objects.filter(id=nid).update(**obj.cleaned_data)
res=models.Teacher.objects.filter(id=nid).first()
# print(ret)
print(res)
# res.c2t.remove()
res.c2t.set(cls_name)
return redirect("/teacher.html")
else:
print("ok")
return render(request, "edit_teacher.html", {'nid': nid, 'obj': obj})

def del_teacher(request,nid):
models.Teacher.objects.filter(id=nid).delete()
return redirect("/teacher.html")

teacher.html

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
</head>
<body>
<h1>老师列表</h1>
<a href="/add_teacher.html">添加老师</a>
<table border="1px">
<thead>
<tr>
<th>老师ID</th>
<th>老师姓名</th>
<th>任教班级</th>
<th>操作</th>
</tr>
</thead>
<tbody>
{% for i in t_list %}
<tr>
<th>{{ i.id }}</th>
<th>{{ i.tname }}</th>
<th>
{% for j in i.c2t.all %}
{{ j.cname }}
{% endfor %}
</th>
<th>
<a href="/edit_teacher/{{ i.id }}">编辑</a>
|
<a href="/del_teacher/{{ i.id }}">删除</a>
</th>
</tr>
{% endfor %}
</tbody>

</table>

</body>
</html>

add_teacher.html

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
</head>
<body>
<h1>添加老师</h1>
<form action="/add_teacher.html" method="POST">
{% csrf_token %}
<p>
老师姓名：{{ obj.tname }}{{ obj.errors.tname.0 }}
</p>
<p>
老师班级：{{ obj.cls_name }}{{ obj.errors.cls_name.0 }}
</p>
<input type="submit" value="提交">

</form>
</body>
</html>

edit_teacher.html

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
</head>
<body>
<h1>编辑老师</h1>
<form method="POST" action="/edit_teacher/{{ nid }}">
{% csrf_token %}
<p>
{{ obj.tname }}{{ obj.errors.tname.0 }}
</p>
<p>
{{ obj.cls_name }}{{ obj.errors.cls_name.0 }}
</p>
<input type="submit" value="提交">
</form>
</body>
</html>

页面展现效果图：