Django无法从post obj中清除图像

Question

当我试图从postform中清除postcover时，返回以下错误：

raise ValueError("The '%s' attribute has no file associated with it." % self.field.name)
ValueError: The 'postcover' attribute has no file associated with it.

例如，对于后附件，其工作罚款。你知道吗

你知道吗型号.py你知道吗

class Post(models.Model):
    author = models.ForeignKey(User, on_delete=models.CASCADE)
    title = models.CharField(verbose_name="Post Title", max_length=40)
    content = models.TextField(verbose_name="Post Content", max_length=10000)
    tag = models.CharField(verbose_name="Tags/Meta - (sep. by comma)", max_length=75, blank=True)
    category = models.ForeignKey(Category, verbose_name="Category", on_delete=models.CASCADE, null=True)
    postattachment = fields.FileField(
        verbose_name="Post Attachment",
        blank=True,
        null=True,
        upload_to=get_file_path_user_uploads,
        validators=[file_extension_postattachment, file_size_postattachment]
    )
    postcover = fields.ImageField(
                              verbose_name="Post Cover",
                              blank=True,
                              null=True,
                              upload_to=get_file_path_user_uploads,
                              validators=[default_image_size, default_image_file_extension],
                              dependencies=[FileDependency(processor=ImageProcessor(
                                  format='PNG', quality=99, scale={'max_width': 700, 'max_height': 700}))])
    published_date = models.DateField(auto_now_add=True, null=True)

   ...

你知道吗表单.py你知道吗

class PostForm(forms.ModelForm):
    class Meta:
        model = Post
        widgets = {
            'title': forms.TextInput(attrs={'placeholder': 'e.g.: Its a sunny day'}),
            'tag': forms.TextInput(attrs={
                'placeholder': 'e.g.: Cars, Blue, Red, Green'}),
        }
        fields = ['title',
                  'category',
                  'content',
                  'tag',
                  'postcover',
                  'postattachment'
                  ]

    captcha = CaptchaField()

    field_order = ['title',
                   'category',
                   'content',
                   'tag',
                   'postcover',
                   'postattachment',
                   'captcha'
                   ]

    def __init__(self, *args, **kwargs):
        kwargs.setdefault('label_suffix', '')
        super(PostForm, self).__init__(*args, **kwargs)
        self.fields['title'].widget.attrs.update({'class': 'class-four-input-fields fieldbreak'})
       ...
        self.fields['postcover'].widget.attrs.update({'class': 'fieldbreak'})
        self.fields['postcover'].label = mark_safe('Cover:')
        self.fields['postcover'].help_text = mark_safe("<h4 class='help_text'>→ Choose a Cover for your Post (max. 2 MB)</h4>")

从我的角度来看，还不清楚为什么会这样。 实际上，postattachment字段没有任何差异，我可以毫无问题地清除这些差异，并且它们都将null&blank设置为True模特儿。派伊？你知道吗

你知道吗视图.py你知道吗

def post_edit(request, pk):
    post = get_object_or_404(Post, pk=pk)
    if request.user == post.author:
        if request.method == "POST":
            form = PostForm(request.POST, request.FILES, instance=post)
            if form.is_valid():
                post = form.save(commit=False)
                post.published_date = timezone.now()
                post.save()
                return redirect('post_detail', pk=post.pk)
        else:
            form = PostForm(instance=post)
        return render(request, 'app/Post/post_edit.html', {'form': form})
    else:
        messages.success(request, 'Uups, something went wrong, please try again or contact the support.')
        return redirect('post_detail', pk=post.pk)

完整跟踪：

完整跟踪：

Traceback (most recent call last):
  File "/home/user123/docs/PyCharm/app/venv/lib/python3.6/site-packages/django/core/handlers/exception.py", line 34, in inner
    response = get_response(request)
  File "/home/user123/docs/PyCharm/app/venv/lib/python3.6/site-packages/django/core/handlers/base.py", line 126, in _get_response
    response = self.process_exception_by_middleware(e, request)
  File "/home/user123/docs/PyCharm/app/venv/lib/python3.6/site-packages/django/core/handlers/base.py", line 124, in _get_response
    response = wrapped_callback(request, *callback_args, **callback_kwargs)
  File "/home/user123/docs/PyCharm/app/app_Accounts/decorators.py", line 33, in _wrapped_view
    return view_func(request, *args, **kwargs)
  File "/home/user123/docs/PyCharm/app/venv/lib/python3.6/site-packages/ratelimit/decorators.py", line 30, in _wrapped
    return fn(*args, **kw)
  File "/home/user123/docs/PyCharm/app/app/views.py", line 473, in post_edit
    post.save()
  File "/home/user123/docs/PyCharm/app/venv/lib/python3.6/site-packages/smartfields/models.py", line 28, in save
    super(SmartfieldsModelMixin, self).save(*args, **kwargs)
  File "/home/user123/docs/PyCharm/app/venv/lib/python3.6/site-packages/django/db/models/base.py", line 718, in save
    force_update=force_update, update_fields=update_fields)
  File "/home/user123/docs/PyCharm/app/venv/lib/python3.6/site-packages/django/db/models/base.py", line 748, in save_base
    updated = self._save_table(raw, cls, force_insert, force_update, using, update_fields)
  File "/home/user123/docs/PyCharm/app/venv/lib/python3.6/site-packages/django/db/models/base.py", line 809, in _save_table
    for f in non_pks]
  File "/home/user123/docs/PyCharm/app/venv/lib/python3.6/site-packages/django/db/models/base.py", line 809, in <listcomp>
    for f in non_pks]
  File "/home/user123/docs/PyCharm/app/venv/lib/python3.6/site-packages/smartfields/fields/__init__.py", line 79, in pre_save
    self.manager.process(model_instance)
  File "/home/user123/docs/PyCharm/app/venv/lib/python3.6/site-packages/smartfields/managers.py", line 154, in process
    self._process(d, instance)
  File "/home/user123/docs/PyCharm/app/venv/lib/python3.6/site-packages/smartfields/managers.py", line 130, in _process
    dependency.process(instance, value, progress_setter=progress_setter)
  File "/home/user123/docs/PyCharm/app/venv/lib/python3.6/site-packages/smartfields/dependencies.py", line 206, in process
    **self._processor_params
  File "/home/user123/docs/PyCharm/app/venv/lib/python3.6/site-packages/smartfields/processors/base.py", line 23, in __call__
    stashed_value=stashed_value, **self.get_params(**kwargs))
  File "/home/user123/docs/PyCharm/app/venv/lib/python3.6/site-packages/smartfields/processors/image.py", line 287, in process
    cur_pos = value.tell()
  File "/home/user123/docs/PyCharm/app/venv/lib/python3.6/site-packages/django/core/files/utils.py", line 21, in <lambda>
    tell = property(lambda self: self.file.tell)
  File "/home/user123/docs/PyCharm/app/venv/lib/python3.6/site-packages/django/db/models/fields/files.py", line 41, in _get_file
    self._require_file()
  File "/home/user123/docs/PyCharm/app/venv/lib/python3.6/site-packages/django/db/models/fields/files.py", line 38, in _require_file
    raise ValueError("The '%s' attribute has no file associated with it." % self.field.name)
ValueError: The 'postcover' attribute has no file associated with it.

有什么好主意，请代我问候。你知道吗

Answer 1

此行为的根本原因如下：

   ...

 dependencies=[FileDependency(processor=ImageProcessor(
                     format='PNG', quality=99, scale={'max_width': 700, 'max_height': 700}))])

我目前没有任何解决这个问题的方法，但似乎imageprocess总是希望在这个领域有所进展