Django 如何使用sorl缩略图制作静态图像的缩略图

我在Django项目中有一个带有化身字段的用户模型：

class User(AbstractBaseUser):

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

化身是不需要的，所以我想使用默认的图像，如果用户还没有上传一个。另一方面，我不想使用

default

参数来更改所有用户未来的默认化身：

class User(AbstractBaseUser):

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

因此，我最终编写了一个

get_avatar

方法，如果存在虚拟形象，该方法将返回一个图像或默认静态图像的路径：

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

但是在这种情况下，

sorl-thumbnail

不会为默认图像生成缩略图

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

我尝试重写该方法以返回图像：

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'))

但我也犯了一个类似的错误：

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.

---

sorl缩略图

已使用

存储功能

。Django将有关如何以及在何处将文件存储到

文件存储系统的决策委派给
。这是一个实际理解文件系统、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，该类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

因此，在您的例子中，django尝试在MEDIA_ROOT下查找映像，但您已经将映像保存在STATIC_ROOT下

如何解决这个问题

作为热修复程序，您可以尝试将图像移动到MEDIA_根目录下，并将在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

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.