Django：获取身份验证用户外键的用户名

Question

I would like to save a jpg file under localhost/media/$username/image.jpg where $username is the username of the foreignkey (User model).

When user is referenced in the content of the object, it returns something like the following:

<django.db.models.fields.related.ForeignKey>

As a result, the image is saved as:

images/<django.db.models.fields.related.ForeignKey>;/image.jpg

Whereas I wanted it to be:

images/sinr0202/image.jpg

where sinr0202 is the username

model.py:

class Image(models.Model):
    PRIVACY = (
        ('P', 'Public'),
        ('F', 'Friends'),
        ('O', 'Only Me'),
    )
    user = models.ForeignKey(User)
    name = models.CharField(max_length=255)
    content = models.FileField(upload_to='media/%s' % (user))
    created = models.DateTimeField(auto_now_add=True)
    privacy = models.CharField(max_length=1, choices=PRIVACY)

Answer 1

You can't do that there, because there is no user at the time the class definition is executed. Instead, set upload_to to a callable, which will be called with the instance and the filename, and returns the full path including filename:

def content_file_name(instance, filename):
    return os.path.join('media', instance.user.username, filename)

class Image(models.Model):
    ...
    content = models.FileField(upload_to=content_file_name)