django form组件
1.渲染标签
2.校验数据
3.展示信息
第一步需要一个form类
from django import forms
class MyForm(forms.Form):
name = forms.CharField(max_length=6)
password = forms.CharField(max_length=8,min_length=3)
email = forms.EmailField(required=True)第二部实例化form对象
form_obj = MyForm({'name':'jason'})
第三步查看数据校验是否合法
form_obj.is_valid() # 只有当所有的字段都校验通过才会返回True? 第四步查看校验错误的信息
form_obj.errors # 这个里面放的是所有校验未通过的字段及错误提示
"""
{
'name': ['Ensure this value has at most 6 characters (it has 7).'],
'password': ['Ensure this value has at least 3 characters (it has 2).'],
'email': ['Enter a valid email address.']
}
"""第五步查看校验通过的数据
form_obj.cleaned_data # 符合校验规则数据都会被放到该对象中
ps:form组件校验数据的规则从上往下依次取值校验
校验通过的放到cleaned_data
校验失败的放到errors
注意:
form中所有的字段默认都是必须传值的(required=True)
校验数据的时候可以都传(多传的数据不会做任何的校验>>>不会影响form校验规则)form组件渲染标签
def reg(request):
form_obj = MyForm()
return render(request,'reg.html',locals())第一种 一行代码渲染所有的数据（扩展性差）
{{ form_obj.as_p }}
{{ form_obj.as_ul }}第二种
<form action="">
<p>{{ form_obj.name.label }}{{ form_obj.name }}</p>
<p>{{ form_obj.password.label }}{{ form_obj.password }}</p>
<p>{{ form_obj.email.label }}{{ form_obj.email }}</p>
<input type="submit">
</form>渲染指定后端字段
后端可以通过在定义字段的时候加上默认属性
from django import forms
class MyForm(forms.Form):
name = forms.CharField(max_length=6,lable = '用户名')
password = forms.CharField(max_length=8,min_length=3，lable='密码')
email = forms.EmailField(required=True)第三种(p标签)
<form action="">
{% for foo in form_obj %}
<p>{{ foo.label }}{{ foo }}</p>
{% endfor %}
</form> 前端取消校验
<form action="" method="post" novalidate>
</form>综合使用
局部钩子和全局钩子
# 局部钩子函数 （单个字段的校验利用局部钩子函数）
def clean_name(self):
name = self.cleaned_data.get('name')
if '666' in name:
self.add_error('name','光喊666是不行的，要有真实力!')
return name # return还是要加上的，兼容性考虑
# 全局钩子函数 （多个字段的校验利用全局钩子函数）
def clean(self):
password = self.cleaned_data.get('password')
confirm_password = self.cleaned_data.get('confirm_password')
if not password == confirm_password:
self.add_error('confirm_password',"两次密码不一致，你这个dsb!")
return self.cleaned_data创建Form类时，主要涉及到 【字段】 和 【插件】，字段用于对用户请求数据的验证，插件用于自动生成HTML;
初始值，input框里面的初始值。
class LoginForm(forms.Form):
username = forms.CharField(
min_length=8,
label="用户名",
initial="张三" # 设置默认值
)
pwd = forms.CharField(min_length=6, label="密码")重写错误信息。
class LoginForm(forms.Form):
username = forms.CharField(
min_length=8,
label="用户名",
initial="张三",
error_messages={
"required": "不能为空",
"invalid": "格式错误",
"min_length": "用户名最短8位"
}
)
pwd = forms.CharField(min_length=6, label="密码")class LoginForm(forms.Form):
...
pwd = forms.CharField(
min_length=6,
label="密码",
widget=forms.widgets.PasswordInput(attrs={'class': 'c1'}, render_value=True)
)单radio值为字符串
class LoginForm(forms.Form):
username = forms.CharField(
min_length=8,
label="用户名",
initial="张三",
error_messages={
"required": "不能为空",
"invalid": "格式错误",
"min_length": "用户名最短8位"
}
)
pwd = forms.CharField(min_length=6, label="密码")
gender = forms.fields.ChoiceField(
choices=((1, "男"), (2, "女"), (3, "保密")),
label="性别",
initial=3,
widget=forms.widgets.RadioSelect()
)class LoginForm(forms.Form):
...
hobby = forms.ChoiceField(
choices=((1, "篮球"), (2, "足球"), (3, "双色球"), ),
label="爱好",
initial=3,
widget=forms.widgets.Select()
)class LoginForm(forms.Form):
...
hobby = forms.MultipleChoiceField(
choices=((1, "篮球"), (2, "足球"), (3, "双色球"), ),
label="爱好",
initial=[1, 3],
widget=forms.widgets.SelectMultiple()
)class LoginForm(forms.Form):
...
keep = forms.ChoiceField(
label="是否记住密码",
initial="checked",
widget=forms.widgets.CheckboxInput()
)class LoginForm(forms.Form):
...
hobby = forms.MultipleChoiceField(
choices=((1, "篮球"), (2, "足球"), (3, "双色球"),),
label="爱好",
initial=[1, 3],
widget=forms.widgets.CheckboxSelectMultiple()
)在使用选择标签时，需要注意choices的选项可以配置从数据库中获取，但是由于是静态字段 获取的值无法实时更新，需要重写构造方法从而实现choice实时更新。
方式一：
from django.forms import Form
from django.forms import widgets
from django.forms import fields
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'].choices = ((1, '上海'), (2, '北京'),)
# 或
self.fields['user'].choices = models.Classes.objects.all().values_list('id','caption')方式二：
from django import forms
from django.forms import fields
from django.forms import models as form_model
class FInfo(forms.Form):
authors = form_model.ModelMultipleChoiceField(queryset=models.NNewType.objects.all()) # 多选
# authors = form_model.ModelChoiceField(queryset=models.NNewType.objects.all()) # 单选添加样式
from django import forms
from django.forms import widgets
password = forms.CharField(max_length=8,min_length=3,error_messages={
'max_length': '密码最长8位',
'required': '密码不能为空',
'min_length':'密码最少3位'
},widget=widgets.PasswordInput(attrs={'class':'c1 form-control'}))
hobby = forms.ChoiceField(
choices=((1, "篮球"), (2, "足球"), (3, "双色球"),),
label="爱好",
initial=3,
widget=forms.widgets.Select()
)
hobby1 = forms.MultipleChoiceField(
choices=((1, "篮球"), (2, "足球"), (3, "双色球"),),
label="爱好",
initial=[1, 3],
widget=forms.widgets.SelectMultiple()
)
keep = forms.ChoiceField(
label="是否记住密码",
initial="checked",
widget=forms.widgets.CheckboxInput()
)
obj = HttpResponse()
return obj
obj = render()
return obj
obj = redirect()
return obj
设置cookie
obj.set_cookie() # 给浏览器设置cookie
获取cookie
request.COOKIE.get('name')
request.COOKIE['name']
def login(request):
if request.method == 'POST':
username = request.POST.get('username')
password = request.POST.get('password')
if username == 'jason' and password == '123':
old_path = request.GET.get('next')
if old_path:
obj = redirect(old_path)
else:
obj = redirect('/home/')
# 用户登录成功 朝浏览器设置一个cookie
obj.set_cookie('name','jason',expires=7*24*3600)
return obj
return render(request,'login.html')用户登录装饰器
from functools import wraps
def login_auth(func):
@wraps(func)
def inner(request,*args,**kwargs):
# 校验cookie
# print(request.get_full_path())
old_path = request.get_full_path()
if request.COOKIES.get('name'):
return func(request,*args,**kwargs)
return redirect('/login/?next=%s'%old_path)
return inner
def logout(request):
rep = redirect("/login/")
rep.delete_cookie("user") # 删除用户浏览器上之前设置的usercookie值
return rep? django默认的session存活时间是两周(14天)
原文：https://www.cnblogs.com/ruhai/p/11042600.html