Django 表单处理

from django.shortcuts import render, redirect
from .forms import ContactForm

def contact_view(request):
    if request.method == 'POST':
        # 使用提交的数据创建表单实例
        form = ContactForm(request.POST)

        if form.is_valid():
            # 表单数据已验证和清理
            name = form.cleaned_data['name']
            email = form.cleaned_data['email']
            subject = form.cleaned_data['subject']
            message = form.cleaned_data['message']
            newsletter = form.cleaned_data['newsletter']

            # 处理数据（保存到数据库、发送邮件等）
            print(f"收到来自 {name} 的留言: {message}")

            # 重定向到成功页面
            return redirect('contact_success')
    else:
        # GET 请求，显示空表单
        form = ContactForm()

    # 渲染模板（包含表单实例）
    return render(request, 'contact.html', {'form': form})

def contact_success(request):
    return render(request, 'contact_success.html')

from django.views.generic import FormView
from .forms import ContactForm
from django.urls import reverse_lazy

class ContactView(FormView):
    template_name = 'contact.html'
    form_class = ContactForm
    success_url = reverse_lazy('contact_success')

    def form_valid(self, form):
        # 表单验证通过时的处理
        name = form.cleaned_data['name']
        email = form.cleaned_data['email']
        message = form.cleaned_data['message']

        # 处理表单数据
        print(f"收到来自 {name} 的留言")

        # 调用父类方法完成重定向
        return super().form_valid(form)

from django import forms
from django.core.validators import validate_email, MinLengthValidator

class UserForm(forms.Form):
    username = forms.CharField(
        max_length=30,
        min_length=3,
        validators=[MinLengthValidator(3)],
        error_messages={
            'required': '用户名不能为空',
            'min_length': '用户名至少3个字符',
            'max_length': '用户名不能超过30个字符'
        }
    )

    email = forms.EmailField(
        validators=[validate_email],
        error_messages={
            'required': '邮箱不能为空',
            'invalid': '请输入有效的邮箱地址'
        }
    )

    age = forms.IntegerField(
        min_value=0,
        max_value=150,
        error_messages={
            'min_value': '年龄不能小于0',
            'max_value': '年龄不能大于150'
        }
    )

from django import forms
from django.core.exceptions import ValidationError

def validate_even(value):
    """自定义验证器：检查是否为偶数"""
    if value % 2 != 0:
        raise ValidationError('%(value)s 不是偶数',
                            params={'value': value})

class CustomForm(forms.Form):
    number = forms.IntegerField(
        validators=[validate_even]
    )

    def clean_username(self):
        """字段级清理和验证"""
        username = self.cleaned_data['username']

        # 检查用户名是否已存在
        if User.objects.filter(username=username).exists():
            raise ValidationError('用户名已存在')

        return username

    def clean(self):
        """表单级验证"""
        cleaned_data = super().clean()
        password = cleaned_data.get('password')
        confirm_password = cleaned_data.get('confirm_password')

        # 检查密码是否匹配
        if password and confirm_password and password != confirm_password:
            raise ValidationError('两次输入的密码不匹配')

        return cleaned_data

def register_view(request):
    if request.method == 'POST':
        form = UserForm(request.POST)
        if form.is_valid():
            # 处理有效数据
            return redirect('success')
        else:
            # 处理验证错误
            print("表单错误:", form.errors)
            print("特定字段错误:", form['username'].errors)
    else:
        form = UserForm()

    return render(request, 'register.html', {'form': form})

<form method="post">
    {% csrf_token %}

    {# 显示表单级错误 #}
    {% if form.non_field_errors %}
        <div class="alert alert-danger">
            {{ form.non_field_errors }}
        </div>
    {% endif %}

    <div class="form-group">
        <label for="{{ form.username.id_for_label }}">用户名</label>
        {{ form.username }}

        {# 显示字段级错误 #}
        {% if form.username.errors %}
            <div class="alert alert-danger mt-2">
                {{ form.username.errors }}
            </div>
        {% endif %}
    </div>

    <button type="submit">注册</button>
</form>

from django.forms import formset_factory
from .forms import ContactForm

# 创建表单集
ContactFormSet = formset_factory(
    ContactForm,
    extra=2,  # 初始显示的表单数量
    max_num=5  # 最大表单数量
)

def manage_contacts(request):
    if request.method == 'POST':
        formset = ContactFormSet(request.POST)
        if formset.is_valid():
            for form in formset:
                if form.cleaned_data:  # 跳过空表单
                    # 处理每个表单的数据
                    name = form.cleaned_data['name']
                    email = form.cleaned_data['email']
                    # ... 保存数据
            return redirect('success')
    else:
        formset = ContactFormSet()

    return render(request, 'contact_formset.html', {'formset': formset})

<form method="post">
    {% csrf_token %}
    {{ formset.management_form }}

    {% for form in formset %}
        <div class="form-row">
            <div class="col">
                {{ form.name.label_tag }}
                                                {{ form.name }}
            </div>
            <div class="col">
                {{ form.email.label_tag }}
                                                {{ form.email }}
            </div>
        </div>
        <hr>
    {% endfor %}

    <button type="submit" class="btn btn-primary">保存所有联系人</button>
</form>

from django import forms

class UploadForm(forms.Form):
    title = forms.CharField(max_length=100)
    file = forms.FileField(
        label='选择文件',
        widget=forms.FileInput(attrs={
            'class': 'form-control-file'
        })
    )

    # 多文件上传
    files = forms.FileField(
        widget=forms.FileInput(attrs={
            'multiple': True,
            'class': 'form-control-file'
        })
    )

def upload_file(request):
    if request.method == 'POST':
        form = UploadForm(request.POST, request.FILES)
        if form.is_valid():
            # 处理上传的文件
            uploaded_file = request.FILES['file']

            # 保存文件
            with open(f'uploads/{uploaded_file.name}', 'wb+') as destination:
                for chunk in uploaded_file.chunks():
                    destination.write(chunk)

            return redirect('success')
    else:
        form = UploadForm()

    return render(request, 'upload.html', {'form': form})