Django - 如何使 ImageField/FileField 可选? [英] Django - how to make ImageField/FileField optional?

问题描述

class Product(models.Model):
    ...    
    image = models.ImageField(upload_to = generate_filename, blank = True)  

当我使用 ImageField (blank=True) 并且没有在管理表单中选择图像时，发生异常.

When I use ImageField (blank=True) and do not select image into admin form, exception occures.

在 django 代码中你可以看到:

In django code you can see this:

class FieldFile(File):
   ....

    def _require_file(self):
        if not self:
            raise ValueError("The '%s' attribute has no file associated with it." % self.field.name)

    def _get_file(self):
        self._require_file()
        ...

Django trac 有关于这个问题的工单 #13327，但似乎不能很快修复.如何使这些字段可选?

Django trac has ticket #13327 about this problem, but seems it can't be fixed soon. How to make these field optional?

推荐答案

blank=True 应该可以工作.如果此属性(默认情况下为 False)设置为 True，那么它将允许输入空值.

blank=True should work. If this attribute, which is False by default, is set to True then it will allow entry of an empty value.

我的文章应用中有以下类:

I have the following class in my article app:

class Photo(models.Model):
        imagename = models.TextField()
        articleimage = models.ImageField(upload_to='photos/%Y/%m/%d', blank=True)

我通过使用 ManyToManyField 关系在另一个类中使用上述类:

I make use of the above class in another class by using the ManyToManyField relationship:

class Article(models.Model):
        pub_date = models.DateTimeField(default=timezone.now)
        slug = models.SlugField(max_length=130)
        title = models.TextField()
        photo = models.ManyToManyField(
            Photo, related_name='photos', blank=True)
        author = models.ForeignKey(User)
        body = models.TextField()
        categories = models.ManyToManyField(
            Category, related_name='articles', null=True)

我想让文章中的图片成为可选的，所以 blank=True 在

I want to make images in my articles optional, so blank=True in

photo = models.ManyToManyField(Photo, related_name='photos', blank=True)

是必要的.如果我愿意，这允许我创建一篇没有任何图像的文章.

is necessary. This allows me to create an article without any images if I want to.

您是否在任何关系中使用 Product 类?如果是这样，请确保在您使用的关系中设置 blank=True.

Are you using class Product in any relationship? If so, make sure to set blank=True in the relationship you are using.

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