Django 中的内联表单验证

Question

我想在管理员更改表单中强制设置整个内联表单集。因此，在我当前的情况下，当我在发票表单（在管理员中）上点击保存时，内联订单表单是空白的。我想阻止人们创建没有关联订单的发票。

有人知道一个简单的方法吗？

在这种情况下，模型字段上的 (required=True) 等常规验证似乎不起作用。

Answer 1

情况有所好转，但仍需要一些工作。 Django现在提供validate_min和min_num属性，如果min_num在formset实例化过程中取自Inline，validate_min只能作为init formset参数传递。所以我的解决方案看起来像这样：

class MinValidatedInlineMixIn:
    validate_min = True
    def get_formset(self, *args, **kwargs):
        return super().get_formset(validate_min=self.validate_min, *args, **kwargs)

class InvoiceOrderInline(MinValidatedInlineMixIn, admin.StackedInline):
    model = InvoiceOrder
    min_num = 1
    validate_min = True

class InvoiceAdmin(admin.ModelAdmin):
    inlines = [InvoiceOrderInline]

Answer 2

class MandatoryInlineFormSet(BaseInlineFormSet):  

    def is_valid(self):
        return super(MandatoryInlineFormSet, self).is_valid() and \
                    not any([bool(e) for e in self.errors])  
    def clean(self):          
        # get forms that actually have valid data
        count = 0
        for form in self.forms:
            try:
                if form.cleaned_data and not form.cleaned_data.get('DELETE', False):
                    count += 1
            except AttributeError:
                # annoyingly, if a subform is invalid Django explicity raises
                # an AttributeError for cleaned_data
                pass
        if count < 1:
            raise forms.ValidationError('You must have at least one of these.')  

class MandatoryTabularInline(admin.TabularInline):  
    formset = MandatoryInlineFormSet

class MandatoryStackedInline(admin.StackedInline):  
    formset = MandatoryInlineFormSet

class CommentInlineFormSet( MandatoryInlineFormSet ):

    def clean_rating(self,form):
        """
        rating must be 0..5 by .5 increments
        """
        rating = float( form.cleaned_data['rating'] )
        if rating < 0 or rating > 5:
            raise ValidationError("rating must be between 0-5")

        if ( rating / 0.5 ) != int( rating / 0.5 ):
            raise ValidationError("rating must have .0 or .5 decimal")

    def clean( self ):

        super(CommentInlineFormSet, self).clean()

        for form in self.forms:
            self.clean_rating(form)


class CommentInline( MandatoryTabularInline ):  
    formset = CommentInlineFormSet  
    model = Comment  
    extra = 1  

Answer 3

@Daniel Roseman 解决方案很好，但我用更少的代码做了一些修改。

class RequiredFormSet(forms.models.BaseInlineFormSet):
      def __init__(self, *args, **kwargs):
          super(RequiredFormSet, self).__init__(*args, **kwargs)
          self.forms[0].empty_permitted = False

class InvoiceOrderInline(admin.StackedInline):
      model = InvoiceOrder
      formset = RequiredFormSet


class InvoiceAdmin(admin.ModelAdmin):
     inlines = [InvoiceOrderInline]

试试这个它也有效:)

Answer 4

Daniel 的回答非常好，它在一个项目中对我有用，但后来我意识到，由于 Django 表单的工作方式，如果您使用 can_delete 并在保存时选中删除框，则可以验证没有任何订单（在这种情况下）。

我花了一段时间试图弄清楚如何防止这种情况发生。第一种情况很简单——不要将要删除的表单包括在计数中。第二种情况比较棘手...如果 所有 删除框都被选中，那么 clean 就不会被调用。

不幸的是，代码并不完全简单。从full_clean 调用clean 方法，在访问error 属性时调用该方法。删除子表单时不会访问此属性，因此永远不会调用 full_clean。我不是 Django 专家，所以这可能是一种糟糕的做法，但它似乎有效。

这是修改后的类：

class InvoiceOrderInlineFormset(forms.models.BaseInlineFormSet):
    def is_valid(self):
        return super(InvoiceOrderInlineFormset, self).is_valid() and \
                    not any([bool(e) for e in self.errors])

    def clean(self):
        # get forms that actually have valid data
        count = 0
        for form in self.forms:
            try:
                if form.cleaned_data and not form.cleaned_data.get('DELETE', False):
                    count += 1
            except AttributeError:
                # annoyingly, if a subform is invalid Django explicity raises
                # an AttributeError for cleaned_data
                pass
        if count < 1:
            raise forms.ValidationError('You must have at least one order')

Answer 5

最好的方法是定义一个自定义表单集，使用一种干净的方法来验证至少存在一个发票订单。

class InvoiceOrderInlineFormset(forms.models.BaseInlineFormSet):
    def clean(self):
        # get forms that actually have valid data
        count = 0
        for form in self.forms:
            try:
                if form.cleaned_data:
                    count += 1
            except AttributeError:
                # annoyingly, if a subform is invalid Django explicity raises
                # an AttributeError for cleaned_data
                pass
        if count < 1:
            raise forms.ValidationError('You must have at least one order')

class InvoiceOrderInline(admin.StackedInline):
    formset = InvoiceOrderInlineFormset


class InvoiceAdmin(admin.ModelAdmin):
    inlines = [InvoiceOrderInline]