Question

我的Django项目中有一个带有头像字段的用户模型：

class User(AbstractBaseUser):

    avatar = models.ImageField(
        null=True,
        blank=True,
        upload_to='user/avatar/',
    )

头像不是必需的，所以如果用户没有上传，我想使用默认图片。另一方面，我不想使用default参数，以便能够在将来为所有用户更改默认头像：

class User(AbstractBaseUser):

    avatar = models.ImageField(
        null=True,
        blank=True,
        default='defaults/no-avatar.png',
        upload_to='user/avatar/',
    )

所以我最后写了一个get_avatar方法，如果存在头像或者是默认静态图像的路径，则返回图像：

@property
def get_avatar(self):
    if self.avatar:
        return self.avatar
    return '{0}defaults/no-avatar.png'.format(settings.STATIC_URL)

但在这种情况下，sorl-thumbnail无法为默认图片生成缩略图

{% thumbnail user.get_avatar "46x46" crop="center" as im %}
    <img title="{{ user }}" src="{{ im.url }}" class="img-circle" />
{% endthumbnail %}

并返回以下错误：

ERROR 2014-09-22 12:49:48,020 thumbnail :: Thumbnail tag failed:
Traceback (most recent call last):
  File "/Users/vera/.virtualenvs/my_app/lib/python2.7/site-packages/sorl/thumbnail/templatetags/thumbnail.py", line 45, in render
    return self._render(context)
  File "/Users/vera/.virtualenvs/my_app/lib/python2.7/site-packages/sorl/thumbnail/templatetags/thumbnail.py", line 97, in _render
    file_, geometry, **options
  File "/Users/vera/.virtualenvs/my_app/lib/python2.7/site-packages/sorl/thumbnail/base.py", line 56, in get_thumbnail
    source_image = default.engine.get_image(source)
  File "/Users/vera/.virtualenvs/my_app/lib/python2.7/site-packages/sorl/thumbnail/engines/pil_engine.py", line 12, in get_image
    buf = StringIO(source.read())
  File "/Users/vera/.virtualenvs/my_app/lib/python2.7/site-packages/sorl/thumbnail/images.py", line 121, in read
    return self.storage.open(self.name).read()
  File "/Users/vera/.virtualenvs/my_app/lib/python2.7/site-packages/django/core/files/storage.py", line 33, in open
    return self._open(name, mode)
  File "/Users/vera/.virtualenvs/my_app/lib/python2.7/site-packages/django/core/files/storage.py", line 159, in _open
    return File(open(self.path(name), mode))
  File "/Users/vera/.virtualenvs/my_app/lib/python2.7/site-packages/django/core/files/storage.py", line 260, in path
    raise SuspiciousFileOperation("Attempted access to '%s' denied." % name)

我尝试重写该方法，以便返回图像：

from django.core.files.images import ImageFile

@property
def get_avatar(self):
    if self.avatar:
        return self.avatar
    return ImageFile(open(os.path.join(settings.STATIC_ROOT, 'defaults/no-avatar.png'), 'r'))

但是我遇到了类似的错误：

ERROR 2014-09-22 12:52:18,448 thumbnail :: Thumbnail tag failed:
Traceback (most recent call last):
  File "/Users/vera/.virtualenvs/my_app/lib/python2.7/site-packages/sorl/thumbnail/templatetags/thumbnail.py", line 45, in render
    return self._render(context)
  File "/Users/vera/.virtualenvs/my_app/lib/python2.7/site-packages/sorl/thumbnail/templatetags/thumbnail.py", line 97, in _render
    file_, geometry, **options
  File "/Users/vera/.virtualenvs/my_app/lib/python2.7/site-packages/sorl/thumbnail/base.py", line 56, in get_thumbnail
    source_image = default.engine.get_image(source)
  File "/Users/vera/.virtualenvs/my_app/lib/python2.7/site-packages/sorl/thumbnail/engines/pil_engine.py", line 12, in get_image
    buf = StringIO(source.read())
  File "/Users/vera/.virtualenvs/my_app/lib/python2.7/site-packages/sorl/thumbnail/images.py", line 121, in read
    return self.storage.open(self.name).read()
  File "/Users/vera/.virtualenvs/my_app/lib/python2.7/site-packages/django/core/files/storage.py", line 33, in open
    return self._open(name, mode)
  File "/Users/vera/.virtualenvs/my_app/lib/python2.7/site-packages/django/core/files/storage.py", line 159, in _open
    return File(open(self.path(name), mode))
  File "/Users/vera/.virtualenvs/my_app/lib/python2.7/site-packages/django/core/files/storage.py", line 260, in path
    raise SuspiciousFileOperation("Attempted access to '%s' denied." % name)
SuspiciousFileOperation: Attempted access to '/Users/vera/workspace/my-website/static/defaults/no-avatar.png' denied.

Answer 1

sorl-thumbnail使用storage functionality。 Django委托决定如何以及在何处将文件存储到file storage system。这是实际理解文件系统，打开和读取文件等内容的对象.Django附带了一个django.core.files.storage.FileSystemStorage类，它实现了基本的本地文件系统文件存储。默认情况下，Django使用MEDIA_ROOT和MEDIA_URL设置在本地存储文件。

所以在你的情况下，django尝试在MEDIA_ROOT下找到图像，但你已经将图像保存在STATIC_ROOT下。

如何修复

作为修补程序，您可以尝试在MEDIA_ROOT下移动图像，并在get_avatar方法中更改路径。或者您可以尝试编写自定义存储，这将适用于两个文件夹。 Example custom storage

如何使用sorl-thumbnail制作静态图像的缩略图

1 个答案: