Question

我的模型中只有一个字段为null = True：

class TestModel(models.Model):
    district = models.ForeignKey(District, on_delete=models.SET_NULL, null=True, default=None)

最简单的形式：

class DistrictForm(ModelForm):
    class Meta:
        model = TestModel
        fields = ['district']

和我的view.py：

def district_details(request, district_id):
    district = get_object_or_404(TestModel, pk=district_id)

    context = {}
    context['district'] = district
    context['frmDistrict'] = DistrictForm(instance=district)
    context['form_title'] = u'{} (id {})'.format(district, district.id)
    return render(request, "editor/district_details.html", context)

def district_update(request, district_id):
    district = get_object_or_404(TestModel, pk=district_id)
    if (request.method == 'POST'):
        form = DistrictForm(data=request.POST, instance=district)
        if form.is_valid():
            district.save()
            messages.success(request, u'District «{}» successfully updated.'.format(district))
            return redirect('editor:district_details', district_id=district.id)
        else:
            messages.warning(request, u"District is not updated. Please correct mistakes in the form." + unicode(form.is_bound))
    else:
        form = DistrictForm(instance=district)
    return district_details(request, district_id=district_id)

和模板：

<!DOCTYPE html>
<html lang="en"><head><meta charset="utf-8"></head><body>
{% for message in messages %}{{ message }}{% endfor %}
{{ form_title }}

<form id="frmSeries" action="{% url 'editor:district_update' district_id=district.id %}" method="POST">
{% csrf_token %}
{{ frmDistrict }}
<input type="submit" name="frmDistrict_submit" value="Сохранить" />
</form>
{% include 'results/panel_footer.html' %}
{{ frmDistrict.errors }}
{{ frmDistrict.non_field_errors }}
{{ request.POST }}
  </body>
</html>

当我更改区域时它工作正常，但问题是当我在表单中选择空值时。 form_is_valid（）为False，但frmDistrict.errors和frmDistrict.non_field_errors都为空！而form.is_bound（）为True。

当我在表单中添加字段时，我遇到了另一个问题。以这种方式修改ModelForm之后：

class DistrictForm(ModelForm):
    district = forms.ModelChoiceField(
        queryset=District.objects.order_by('name'),
        empty_label="empty",
        required=False)
    class Meta:
        model = TestModel
        fields = ['district']

当我选择＆＃34;空＆＃34;在下拉列表中，表单成功提交，但是＆＃34; district＆＃34;这个领域并没有改变！

有什么想法吗？提前谢谢！

具有外键的Django ModelForm：当选择空值时，form.is_vaild = False

0 个答案: