Django-forms组件

forms组件是用来干什么的？

1、校验数据；

2、页面显示错误信息；

3、渲染页面；

4、重置数据。

views.py中：

from django import forms

class BookForm(forms.Form):

    title = forms.CharField(max_length=32)
    price = forms.IntegerField()
    email = forms.EmailField()

其中，title、price、email是用来校验的字段。我们可以在Django Console中对它们进行校验：

 

Django Console：

#校验某个类下的字段，我们需要导入要校验的类
from app01.views import BookForm

fm=BookForm({"title":"yuan","price":123,"email":"123"})

fm.is_valid()  # 合法返回True，不和法返回False
False

fm.cleaned_data  # 显示合法字段及其值（字典格式）
{'title': 'yuan', 'price': 123}

fm.errors  # 显示不合法字段及其值（字典格式）
{'email': ['Enter a valid email address.']}
fm=BookForm({"title":"yuan","price":123,"email":"[email protected]"})
fm.is_valid()
True
fm.cleaned_data
{'title': 'yuan', 'price': 123, 'email': '[email protected]'}
fm.errors
{}

fm=BookForm({"title":"yuan","price":123,"email":"[email protected]","abc":123})  # 只要需要校验的字段是合法的，那就是合法的，加其他内容无所谓
fm.is_valid()
True
fm.cleaned_data
{'title': 'yuan', 'price': 123, 'email': '[email protected]'}
fm.errors
{}
fm=BookForm({"title":"yuanhfdurhgdjfhdfruhfugfhrfherjhfeuhuerhtu","price":123,"email":"[email protected]","abc":123})
fm.is_valid()
False
fm.cleaned_data
{'price': 123, 'email': '[email protected]'}
fm.errors
{'title': ['Ensure this value has at most 32 characters (it has 42).']}

 

登录示例：

　　1.用户名长度不能低于5位；

　　2.密码必须是纯数字；

　　3.邮箱必须符合邮箱格式；

　　4.如果输入数据格式有问题，显示给用户。

 

首先，在数据库中创建一张表（用于存取合格数据）

models.py:

class UserInfo(models.Model):
    user=models.CharField(max_length=32)
    pwd=models.CharField(max_length=32)
    email=models.CharField(max_length=32)

 

发送http://127.0.0.1:8000/reg/请求：

urls.py:

from app01 import views
urlpatterns = [
    path('admin/', admin.site.urls),
    path('reg/', views.reg),
]

views.py:

from django import forms
from app01.models import UserInfo

class UserForm(forms.Form):
    msg={"required":"该字段不能为空"}
    user=forms.CharField(min_length=5, error_messages=msg)
    pwd=forms.IntegerField(error_messages=msg)
    email=forms.EmailField(error_messages=msg)

def reg(request):

    if request.method=="POST":
        print(request.POST)

        # 数据校验
        form=UserForm(request.POST)
        if form.is_valid():
            print(form.cleaned_data)
            UserInfo.objects.create(**form.cleaned_data)
            return HttpResponse("ok")
        else:
            # print(form.cleaned_data)
            # print(form.errors)  # {"user":["",""]}
            # print(form.errors.get("user"))
            # print(form.errors.get("user")[0])

            errors=form.errors
            return render(request, "reg.html", {"errors":errors})
    else:
        return render(request, "reg.html")

reg.html:

"en">

    "UTF-8">
    




"" method="post">
    {% csrf_token %}
    
用户名 "text" name="user">class="error">{{ errors.user.0 }}
    
密码 "text" name="pwd">class="error">{{ errors.pwd.0 }}
    
邮箱 "text" name="email">class="error">{{ errors.email.0 }}
    "submit">