Question

I have this model which has Image field to be uploaded. It has a foreign key reference to another class.

from django.template.defaultfilters import slugify

def upload_to(path, attribute):

    def upload_callback(instance, filename):
        return '%s%s/%s' % (path, unicode(slugify(getattr(instance, attribute))), filename)

    return upload_callback


class Data(models.Model):
    place = models.CharField(max_length=40)
    typeOfProperty = models.CharField(max_length=30)
    typeOfPlace = models.CharField(max_length=20)
    price = models.IntegerField()
    ownerName = models.CharField(max_length=80)

    
class ImageData(models.Model):
    property = models.ForeignKey(Data, related_name='images')
    image = models.ImageField(upload_to = upload_to('image/', 'ownerName'),blank=True,null=True)
    
    def __unicode__(self):
        return self.property.ownerName

I have refered this This Web Page to create a dynamic field for images to be stored.

My doubt is can I use the onerName as the attribute in (as the ownerName is in the super class) :

image = models.ImageField(upload_to = upload_to('image/', 'ownerName'),blank=True,null=True)

How does Django consider this request that is need to be served?

Please can anyone explain me this?

Answer 1

'ownerName' is not going to work. It’s quite complicated to do the definition of what you want to save in the ImageField directly. Maybe you should do something like this:

def upload_to(path):

    def upload_callback(instance, filename):
        return '%s%s/%s' % (path, unicode(slugify(instance.property.ownerName), filename)

    return upload_callback

If you really want to make it as dynamic as possible you have to pass something like 'property.ownerName' to the function, split the string, retrieve attrtibute property from ImageData instance and then attribute ownerName from its foreign key instance.

Though I think this makes things way to complicated and you better define extra functions for different use cases.