Django:表格内联表单的表单验证

Question

你好，我已经注册了这样的模型

# models.py
class Property(models.Model):
    address = models.TextField()
    ...

class PropertyImage(models.Model):
    property = models.ForeignKey(Property, related_name='images')
    image = models.ImageField()
    is_front = models.BooleanField(default=False)

和:

# admin.py
class PropertyImageInline(admin.TabularInline):
    model = PropertyImage
    extra = 3

class PropertyAdmin(admin.ModelAdmin):
    inlines = [ PropertyImageInline, ]

admin.site.register(Property, PropertyAdmin)

前面的图片是 bool 值，所以我知道哪张图片将显示在公告上

问题

我不知道如何进行验证，所以我可以抛出一个错误如果 0 或更多的 1 张图片被选为 is_front 你能帮我进行管理表单验证吗？

谢谢!

Answer 1

您可以这样做的一种方法是在 PropertyImage 上创建一个 clean 方法，该方法将用于验证管理中的数据。

from django.core.exceptions import ValidationError

class PropertyImage(models.Model):
    property = models.ForeignKey(Property, related_name='images')
    image = models.ImageField()
    is_front = models.BooleanField(default=False)

    # Clean will only be called within the Admin.
    # If you have other places this needs to be verified,
    # you'll need to call it manually or move this logic into a ModelForm.
    def clean(self):
        images = self.property.images.all()
        # If we're editing, we want to exclude ourselves from the check.
        if self.id:
            images = images.exclude(id=self.id)
        if self.is_front and images.filter(is_front=True).exists():
            raise ValidationError("Only one image can have is_front set.")