Django表单验证失败调试指南与最佳实践

# 示例：在视图中调试 form.errors
def place_order(request, total=0, quantity=0):
    # ... (其他逻辑，如获取购物车项、计算总价等) ...

    if request.method == "POST":
        form = OrderForm(request.POST)
        if form.is_valid():
            # ... (表单验证成功后的逻辑) ...
            return render(request, "PixelCart/payments.html", context)
        else:
            # 表单验证失败时，打印错误信息
            print("表单验证失败，错误信息：", form.errors)
            # 此时，不应简单重定向，而应重新渲染表单，并显示错误
            # ... (准备上下文并重新渲染表单) ...
            return redirect("checkout") # 原始代码的重定向，我们将在后续章节优化
    # ... (GET请求处理) ...

<!-- forms.html (或你的 checkout.html) -->
<form method="post">
    {% csrf_token %}

    <!-- 显示非字段错误 -->
    {% if form.non_field_errors %}
        <div class="alert alert-danger">
            {% for error in form.non_field_errors %}
                <p>{{ error }}</p>
            {% endfor %}
        </div>
    {% endif %}

    <!-- 遍历所有字段并显示其错误 -->
    {% for field in form %}
        <div class="form-group">
            {{ field.label_tag }}
            {{ field }}
            {% if field.errors %}
                <ul class="errorlist">
                    {% for error in field.errors %}
                        <li>{{ error }}</li>
                    {% endfor %}
                </ul>
            {% endif %}
            {% if field.help_text %}
                <small class="form-text text-muted">{{ field.help_text }}</small>
            {% endif %}
        </div>
    {% endfor %}

    <button type="submit" class="btn btn-primary">提交订单</button>
</form>

import datetime
from django.shortcuts import render, redirect
from .models import CartItem, Order # 假设你的模型在这里
from .forms import OrderForm # 假设你的表单在这里

def place_order(request, total=0, quantity=0):
    current_user = request.user

    # 如果购物车为空，重定向到商店页面
    cart_items = CartItem.objects.filter(user=current_user)
    cart_count = cart_items.count()
    if cart_count <= 0:
        return redirect('store')

    grand_total = 0
    tax = 0

    for cart_item in cart_items:
        total += (cart_item.product.price * cart_item.quantity)
        quantity += cart_item.quantity

    tax = (2 * total) / 100
    grand_total = total + tax

    if request.method == "POST":
        form = OrderForm(request.POST)
        if form.is_valid():
            # 表单验证成功：保存订单数据
            data = Order()
            data.user = current_user
            data.first_name = form.cleaned_data['first_name']
            data.last_name = form.cleaned_data['last_name']
            data.phone = form.cleaned_data['phone']
            data.email = form.cleaned_data['email']
            data.address_line_1 = form.cleaned_data['address_line_1']
            data.address_line_2 = form.cleaned_data['address_line_2']
            data.country = form.cleaned_data['country']
            data.state = form.cleaned_data['state']
            data.city = form.cleaned_data['city']
            data.order_note = form.cleaned_data['order_note']
            data.order_total = grand_total
            data.tax = tax
            data.ip = request.META.get('REMOTE_ADDR')
            data.save()

            # 生成订单号
            yr = int(datetime.date.today().strftime('%Y'))
            dt = int(datetime.date.today().strftime('%d'))
            mt = int(datetime.date.today().strftime('%m'))
            d = datetime.date(yr, mt, dt)
            current_date = d.strftime("%Y%m%d")

            order_number = current_date + str(data.id)
            data.order_number = order_number
            data.save()

            # 获取订单对象并渲染支付页面
            order = Order.objects.get(
                user=current_user, is_ordered=False, order_number=order_number)
            context = {
                "order": order,
                "cart_items": cart_items,
                "total": total,
                "tax": tax,
                "grand_total": grand_total,
            }
            return render(request, "PixelCart/payments.html", context)
        else:
            # 表单验证失败：重新渲染 checkout 页面，并传递表单和错误信息
            print("表单验证失败，错误信息：", form.errors) # 调试信息
            context = {
                "form": form, # 传递带有错误信息的表单实例
                "cart_items": cart_items,
                "total": total,
                "tax": tax,
                "grand_total": grand_total,
            }
            # 假设你的 checkout 页面模板是 'PixelCart/checkout.html'
            return render(request, "PixelCart/checkout.html", context)
    else:
        # GET 请求：初始化一个空表单并渲染 checkout 页面
        form = OrderForm()
        context = {
            "form": form,
            "cart_items": cart_items,
            "total": total,
            "tax": tax,
            "grand_total": grand_total,
        }
        return render(request, "PixelCart/checkout.html", context)