六十一Django之form组件

Posted 2022-01-19 zhangguosheng1121

一、form组件

1、校验数据

# 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)
#第二步实例化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

# 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)
        

2、渲染标签

from django import forms

class MyForm(forms.Form):
    username = forms.CharField(max_length=6, label=‘用户名‘)
    password = forms.CharField(max_length=8, min_length=3)
    email = forms.EmailField()

def reg(request):
    # 生成一个空对象
    form_obj = MyForm()
    return render(request, ‘reg.html‘, locals())

views.py

reg.html：

<h1>第一种渲染标签的方式</h1>
 form_obj.as_p 
 form_obj.as_ul 

<h1>第二种渲染标签的方式</h1>
<form action="">
    <p> form_obj.username.label  form_obj.username </p>
    <p> form_obj.password.label  form_obj.password </p>
    <p> form_obj.email.label  form_obj.email </p>
    <input type="submit">
</form>

<h1>第三种渲染标签的方式</h1>
<form action="" method="post">
    % for foo in form_obj %
    <p> foo.label  foo </p>
    % endfor %
    <input type="submit">
</form>

3、展示数据

①前端取消校验

②展示数据输入是否合法

 

from django import forms


class MyForm(forms.Form):
    username = forms.CharField(max_length=6, label=‘用户名‘, error_messages=
        ‘max_length‘: ‘用户名最长为6位‘,
        ‘required‘: ‘用户名不能为空‘
    )
    password = forms.CharField(max_length=8, min_length=3, error_messages=
        ‘max_length‘: ‘密码最长为8位‘,
        ‘required‘: ‘密码不能为空‘,
        ‘min_length‘: ‘密码最少3位‘
    )
    email = forms.EmailField(error_messages=
        ‘required‘: ‘邮箱不能为空‘,
        ‘invalid‘: ‘邮箱格式不正确‘
    )


def reg(request):
    # 生成一个空对象
    form_obj = MyForm()
    if request.method == ‘POST‘:
        print(request.POST)
        form_obj = MyForm(request.POST)
        if form_obj.is_valid():
            print(form_obj.cleaned_data)
            models.User.objects.create(**form_obj.cleaned_data)
    return render(request, ‘reg.html‘, locals())

views.py

reg.html：

<h1>第三种渲染标签的方式</h1>
<form action="" method="post" novalidate>
    % for foo in form_obj %
        <p>
             foo.label  foo 
            <span> foo.errors.0 </span>
        </p>
    % endfor %
    <input type="submit">
</form>

 

 

二、django操作cookie，session