django 文件上传 - 在编辑模板中隐藏当前显示的图片链接

Question

我有一个测试模板，允许用户将上传的文件图像以及图像标题作为字符字段添加到用户帐户。这工作正常。

我现在正在尝试允许用户编辑已上传的文件图像和图像标题详细信息。

是否可以隐藏图片链接并在其位置显示图片？

我已经阅读了django docs，搜索了SO 和 Google，并且断断续续地工作了 2 1/2 天，但我仍然无法解决这个问题。

似乎有很多关于如何上传新文件图像的信息，而不是如何编辑已经上传的文件图像。

这是我的 models.py 代码：

def _get_document_upload_location(instance, filename):
"""
Using a function instead of a lambda to make migrations happy. DO NOT remove or rename this function in the future, as it will break migrations.
@param instance: model instance that owns the FileField we're generating the upload filename for.
@param filename: Original file name assigned by django.
"""
return 'attachments/%d/%s' % (instance.user.id, uuid.uuid4())

class AttachmentDetails(models.Model, FillableModelWithLanguageVersion):
    user = models.ForeignKey(User)
    language_version = models.ForeignKey('LanguageVersion')
    attachment_document = models.FileField(upload_to=_get_document_upload_location)
    attachment_title = models.CharField(null=False, blank=False, max_length=250)
    attachment_timestamp_added = models.DateTimeField(auto_now_add=True, auto_now=False)
    attachment_timestamp_updated = models.DateTimeField(auto_now=True, auto_now_add=False)

这是我的views.py文件代码：

def attachment_details_edit(request, attachment_details_id):
    try:
        attachment_details = AttachmentDetails.objects.get(pk=attachment_details_id, user=request.user)
    except AttachmentDetails.DoesNotExist:
        return redirect(settings.MENU_DETAIL_LINK_ATTACHMENT_DETAILS)
    language_versions = LanguageVersion.objects.filter(user=request.user).select_related('language_version')
    available_languages = get_available_language_details(language_versions, request.user.userprofile.language_preference)
    attachment_details_num = request.user.attachmentdetails_set.count()
    language_code = attachment_details.language_version.language_code
    language_code_disabled = attachment_details.language_version.language_code_disabled
    language_preference = request.user.userprofile.language_preference
    if language_code_disabled:
        return redirect(settings.MENU_DETAIL_LINK_ATTACHMENT_DETAILS)
    if request.method == 'GET':
        language_code = attachment_details.language_version.language_code
        form = AttachmentDetailsForm(
                available_languages,
                language_preference=request.user.userprofile.language_preference,
                file_required=False,
                initial=dict(
                    model_to_dict(attachment_details),
                    language_code=language_code
                )
        )
    elif request.method == 'POST':
        form = AttachmentDetailsForm(
            available_languages,
            language_preference,
            False,  # file_required
            request.POST,
            request.FILES
        )
        if form.is_valid():
            cd = form.cleaned_data
            if cd['attachment_document'] is not None:
                print 'removing previously uploaded file'
                attachment_details.attachment_document.delete(save=False)
            attachment_details.fill(cd)
            attachment_details.save()
            messages.success(request, _('successfully updated.'))
            return redirect(settings.MENU_DETAIL_LINK_ATTACHMENT_DETAILS)

编辑

这是我试图向用户隐藏的示例 - 代替链接，显示实际上传的文件图像。 下图是django admin，但我想隐藏链接，在编辑模板中显示上传的图片：

我有一个相关的帖子here。

Answer 1

要隐藏当前显示的图像链接，您可以简单地覆盖 get_context（下面是类似于 FileInput 的 ClearableFileInput 示例）。

在寻找此类解决方案时检查源代码非常有用。

Django 是一个开源模块，因此您可以在 GitHub 上查找源代码： https://github.com/django/django/blob/main/django/forms/widgets.py

class ClearableFileInputCustom(forms.ClearableFileInput):
    def get_context(self, name, value, attrs):
        context = super().get_context(name, value, attrs)
        context['widget']['is_initial'] = False
        return context

Answer 2

我在一个旧项目中使用了this snippet。这不是很好，因为您必须刷新页面/保存模型，但它可以满足您的需求。

小部件：

class AdminImageWidget(forms.FileInput):                                    
    """A ImageField Widget for admin that shows a thumbnail."""             

    def __init__(self, attrs={}):   # pylint: disable=E1002,W0102           
        super(AdminImageWidget, self).__init__(attrs)                       

    def render(self, name, value, attrs=None):  # pylint: disable=E1002     
        output = []                                                         
        css = {'style': 'clear:left;float:left;margin:1em 1em 0 0;'}        
        output.append(super(AdminImageWidget, self).render(name, value,     
                                                           attrs=css))      
        if value and hasattr(value, "url"):                                 
            output.append(('<a target="_blank" href="%s">'                  
                           '<img src="%s" alt="" '                          
                           'style="float:left;border:1px solid black;" /></a> '
                           % (value.url, value.url)))                       
        return mark_safe(u''.join(output)) 

在管理员中使用它：

class SomeAdminForm(forms.ModelForm):
    class Meta:
        model = MyModel
        widgets = {
            'my_image_field_name': AdminImageWidget(),
        }

class SomeAdmin(admin.ModelAdmin):
    form = SomeAdminForm

Answer 3

您必须在模板中设置 img 标记的 src 属性才能成功显示图像。

<img src="{{attachment_details.file_url}}"/>

{{attachment_details.file_url}} 当然必须替换为您要检索文件的网址。