Question

信息：

我想创建嵌套表单，最好通过以下提供的示例进行描述：

http://yergler.net/blog/2009/09/27/nested-formsets-with-django/

此页面的教程似乎相当不错＆amp;＆amp;它试图完成我遇到的确切问题。

当没有POST请求数据时（例如，我们正在从数据库执行初始填充），views.py文件中的此实现似乎存在问题。

可以在上面提供的URL上看到代码（如果需要，我可以发布一些代码，但我担心它会从这里提供的信息中删除）。

以下是失败的views.py代码（粗体）：

block = get_object_or_404(models.Block, id=block_id)

if request.method == 'POST':
    formset = forms.BuildingFormset(request.POST, instance=block)

    if formset.is_valid():
        rooms = formset.save_all()

        return redirect('block_view', block_id=block.id)

else:
    formset = forms.BuildingFormset(instance=block)  #This is the line that is throwing the ValidationError

我得到的错误信息是：

ValidationError at "urlName":
[u'ManagementForm data is missing or has been tampered with']

我已经挖得更深了，看来这个失败发生在line site-packages / django / forms / formsets.py

is_valid()检查失败，因为某些管理层需要的数据（form-TOTAL_FORMS，form-INITIAL_FORMS和form-MAX_NUM_FORMS）无效。以下是self.errors的实际输出：

{u'TOTAL_FORMS': [u'This field is required.'], u'INITIAL_FORMS': [u'This field is required.']}

代码：

edit_building.html：

{{buildings.management_form}}

{building for buildings.forms％}
 {{ building }}

 {% if building.nested %}   
   {% for formset in building.nested %}   
     {{ formset.as_table }}   
   {% endfor %}   
 {% endif %}
{％endfor％}

views.py：

def should_delete(self, form):
    """Convenience method for determining if the form’s object will
    be deleted; cribbed from BaseModelFormSet.save_existing_objects."""

    if self.can_delete:
        raw_delete_value = form._raw_value(DELETION_FIELD_NAME)
        should_delete = form.fields[DELETION_FIELD_NAME].clean(raw_delete_value)
        return should_delete

    return False

def save_all(self, commit=True):
    """Save all formsets and along with their nested formsets."""

    # Save without committing (so self.saved_forms is populated)
    # — We need self.saved_forms so we can go back and access
    #    the nested formsets
    objects = self.save(commit=False)

    # Save each instance if commit=True
    if commit:
        for o in objects:
            o.save()

    # save many to many fields if needed
    if not commit:
        self.save_m2m()

    # save the nested formsets
    for form in set(self.initial_forms + self.saved_forms):
        if self.should_delete(form): continue

        for nested in form.nested:
            nested.save(commit=commit)

forms.py：

def should_delete(self, form):
    """Convenience method for determining if the form’s object will
    be deleted; cribbed from BaseModelFormSet.save_existing_objects."""

    if self.can_delete:
        raw_delete_value = form._raw_value(DELETION_FIELD_NAME)
        should_delete = form.fields[DELETION_FIELD_NAME].clean(raw_delete_value)
        return should_delete

    return False

def save_all(self, commit=True):
    """Save all formsets and along with their nested formsets."""

    # Save without committing (so self.saved_forms is populated)
    # — We need self.saved_forms so we can go back and access
    #    the nested formsets
    objects = self.save(commit=False)

    # Save each instance if commit=True
    if commit:
        for o in objects:
            o.save()

    # save many to many fields if needed
    if not commit:
        self.save_m2m()

    # save the nested formsets
    for form in set(self.initial_forms + self.saved_forms):
        if self.should_delete(form): continue

        for nested in form.nested:
            nested.save(commit=commit)

说明：

我已经查看了https://docs.djangoproject.com/en/dev/topics/forms/formsets/#understanding-the-managementform的django文档，但没有找到任何有用的内容来讨论DJANGO如何自动填充这些值
我正在使用Django V1.5

问题：

如果没有POST数据且表单仅由数据库生成，那么'form-TOTAL_FORMS'＆amp;＆amp;正确填写'form-INITIAL_FORMS'数据来解决这个失败？

Answer 1

<强>更新

在查看了the example之后，我在forms.py方法的末尾add_fields()中显示了一个如下所示的代码段：

# store the formset in the .nested property
form.nested = [
    TenantFormset(data = self.data,
                  instance = instance,
                  prefix = 'TENANTS_%s' % pk_value)
]

data参数导致问题，因为它最初是空的，并且Django内部将通过与此类似的条件确定表单is bound：

self.is_bound = data is not None

# Example
>>> my_data = {}
>>> my_data is not None
True

正如您所看到的，Python中的空字典不是None，因此即使不是TenantFormset，bound也会被视为# store the formset in the .nested property form.nested = [ TenantFormset(data = self.data if any(self.data) else None, instance = instance, prefix = 'TENANTS_%s' % pk_value) ]形式。您可以使用以下内容修复它：

<form method="post">
    {{ formset.management_form }}
    <table>
        {% for form in formset %}
        {{ form }}
        {% endfor %}
    </table>
</form>

您可以发布视图和表单代码以及表单的模板代码吗？

我的猜测是你没有在模板中使用'management_form'（它添加了你缺少的“form-TOTAL_FORMS”和“form-INITIAL_FORMS”字段），即

{{1}}

Django管理表单失败，因为'form-TOTAL_FORMS'和'form-INITIAL_FORMS'没有正确填充

信息：

代码：

说明：

问题：

1 个答案: