Django 之 Form
forms组件
1. 校验字段功能
针对一个实例：注册用户讲解。
模型：models.py
class UserInfo(models.Model): name=models.CharField(max_length=32) pwd=models.CharField(max_length=32) email=models.EmailField() tel=models.CharField(max_length=32)
视图函数：register
from django.forms import widgets
from django.core.exceptions import ValidationError
wid_01 = widgets.TextInput(attrs={"class": "form-control"}) #用了bootstrap，所以加个样式属性
wid_02 = widgets.PasswordInput(attrs={"class": "form-control"}) #注意！！ 在校验失败后，form对象不保存PasswordInput的value值,所以页面要重新输入
class UserForm(forms.Form):
name = forms.CharField(min_length=3, label="用户名", error_messages={"required": "该字段不能为空", "min_length": "最小长度为3"},
widget=wid_01
)
pwd = forms.CharField(min_length=4, label="密码",
widget=wid_02
)
r_pwd = forms.CharField(min_length=4, label="确认密码", error_messages={"required": "该字段不能为空"},
widget=wid_02)
email = forms.EmailField(label="邮箱", error_messages={"required": "该字段不能为空", "invalid": "格式错误"},
widget=wid_01)
tel = forms.CharField(label="手机号", widget=wid_01)
def register(request):
if request.method == "POST":
print(request.POST)
# form=UserForm({"name":"yu","email":"123@qq.com","xxxx":"alex"})
form = UserForm(request.POST) # form表单的name属性值应该与forms组件字段名称一致
print(form.is_valid()) # 返回布尔值
if form.is_valid():
print(form.cleaned_data) # {"name":"yuan","email":"123@qq.com"}
else:
print(form.cleaned_data) # {"email":"123@qq.com"}
# print(form.errors) # {"name":[".........."]}
# print(type(form.errors)) # ErrorDict : {"校验错误的字段":["错误信息",]}
# print(form.errors.get("name"))
# print(type(form.errors.get("name"))) # ErrorList ["错误信息",]
# print(form.errors.get("name")[0])
return render(request, "register.html", locals())
'''
form.is_valid() :返回布尔值
form.cleaned_data :{"name":"yuan","email":"123@qq.com"}
form.errors :{"name":[".........."]}
'''
form = UserForm()
return render(request, "register.html", locals())
2. 渲染标签功能
2.1 渲染方式1
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>Title</title> <!-- 最新版本的 Bootstrap 核心 CSS 文件 --> <link rel="stylesheet" href="https://cdn.bootcss.com/bootstrap/3.3.7/css/bootstrap.min.css" integrity="sha384-BVYiiSIFeK1dGmJRAkycuHAHRg32OmUcww7on3RYdg4Va+PmSTsz/K68vbdEjh4u" crossorigin="anonymous"> </head> <body> <h3>注册页面</h3> <div class="container"> <div class="row"> <div class="col-md-6 col-lg-offset-3"> <form action="" method="post"> {% csrf_token %} <div> <label for="">用户名</label> {{ form.name }} </div> <div> <label for="">密码</label> {{ form.pwd }} </div> <div> <label for="">确认密码</label> {{ form.r_pwd }} </div> <div> <label for=""> 邮箱</label> {{ form.email }} </div> <input type="submit" class="btn btn-default pull-right"> </form> </div> </div> </div> </body> </html>
2.2 渲染方式2
<form action="" method="post"> {% csrf_token %} {% for field in form %} <div> <label for="">{{ field.label }}</label> {{ field }} </div> {% endfor %} <input type="submit" class="btn btn-default pull-right"> </form>
2.3 渲染方式3
<form action="" method="post"> {% csrf_token %} {{ form.as_p }} <input type="submit" class="btn btn-default pull-right"> </form>
3. 显示错误与重置输入信息功能
视图
def register(request): if request.method=="POST": form=UserForm(request.POST) if form.is_valid(): print(form.cleaned_data) # 所有干净的字段以及对应的值 else: print(form.cleaned_data) # print(form.errors) # ErrorDict : {"校验错误的字段":["错误信息",]} print(form.errors.get("name")) # ErrorList ["错误信息",] return render(request,"register.html",locals()) form=UserForm() return render(request,"register.html",locals())
模板
<form action="" method="post" novalidate> {% csrf_token %} {% for field in form %} <div> <label for="">{{ field.label }}</label> {{ field }} <span class="pull-right" style="color: red">{{ field.errors.0 }}</span> </div> {% endfor %} <input type="submit" class="btn btn-default"> </form>
4. 局部钩子与全局钩子
视图
# forms组件
from django import forms
from django.core.exceptions import ValidationError
class UserForm(forms.Form):
username = forms.CharField(min_length=3, max_length=6, label="用户名",
error_messages={"required": "该字段不能为空", "min_length": "最小长度为3", "max_length": "最大长度为6"}, )
password = forms.CharField(max_length=32, label="密码", error_messages={"required": "该字段不能为空"})
r_pwd = forms.CharField(max_length=32, label="确认密码", error_messages={"required": "该字段不能为空"})
email = forms.EmailField(label="邮箱", error_messages={"required": "该字段不能为空", "invalid": "格式错误"})
phone = forms.CharField(max_length=32, label="手机号")
def __init__(self, *args, **kwargs): # 给每个标签添加属性
super().__init__(*args, **kwargs)
for field in self.fields.values():
field.widget.attrs['class'] = 'form-control'
# 局部钩子
def clean_username(self):
val = self.cleaned_data.get("username")
if not val.isdigit():
return val
else:
raise ValidationError("用户名不能是纯数字!")
# 全局钩子
def clean(self):
pwd = self.cleaned_data.get("password")
r_pwd = self.cleaned_data.get("r_pwd")
if pwd == r_pwd:
return self.cleaned_data
else:
raise ValidationError('两次密码不一致!')
def register(request):
form = UserForm()
if request.method == "POST":
form = UserForm(request.POST)
if form.is_valid():
print(form.cleaned_data)
user = UserInfo.objects.create_user(username=request.POST.get("username"),
password=request.POST.get("password"), phone=request.POST.get("phone"),
email=request.POST.get("email"))
return redirect("/blog/login/")
else:
errors = form.errors.get("__all__")
return render(request, "register.html", locals())
return render(request, "register.html", locals())
模板
<form action="" method="post"> {% csrf_token %} <p>{{ form.username.label }} {{ form.username }} <span class="pull-right error">{{ form.username.errors.0 }}</span> </p> <p>{{ form.password.label }} {{ form.password }} <span class="pull-right error">{{ form.password.errors.0 }}</span> </p> <p>{{ form.r_pwd.label }} {{ form.r_pwd }} <span class="pull-right error">{{ form.r_pwd.errors.0 }}</span> <span class="pull-right error">{{ errors.0 }}</span> </p> <p>{{ form.email.label }} {{ form.email }}<span class="pull-right error">{{ form.email.errors.0 }}</span></p> <p>{{ form.phone.label }} {{ form.phone }} <span class="pull-right error">{{ form.phone.errors.0 }}</span></p> <button type="submit" class="btn btn-success">提交注册</button> </form>
