yazzgoth.org

from django.dispatch import dispatcher
import shutil, os, settings, re

class CustomImageField(models.ImageField):
    """
    Model class should have a method like:

        def personalize_name(self, field_attname):
            return "path/to/file/%d.jpg" % self.id

    """
    def contribute_to_class(self, cls, name):
            super(CustomImageField, self).contribute_to_class(cls, name)
            dispatcher.connect(self._save, models.signals.pre_save, sender=cls)

    def _save(self, instance):
        oldname = getattr(instance, self.attname)
        extension = re.findall(r'.[wd]+$', oldname)
        if len(extension)>0:
            extension = extension[0]
        else: extension = ""
        filename = instance.personalize_name(self.attname)
        filename = self.upload_to + '_'.join(re.findall(r'[a-zA-Z0-9]+', filename)) + extension # leave only alphanum characters and add extension and add extension
        try:
            shutil.move(os.path.join(settings.MEDIA_ROOT, oldname), os.path.join(settings.MEDIA_ROOT, filename))
        except IOError:
            filename = oldname
        setattr(instance, self.attname, filename)

    def db_type(self):
        """Required by Django for ORM."""
        return 'varchar(100)'

class MyPhoto(models.Model):
    photo = CustomImageField(upload_to="photos/")
    owner = models.CharField(max_length=32)
    uploaded = models.DateTimeField(auto_add_now=True)

    def personalize_name(self, field_attname):
        return "%s %s" % ( self.owner, self.uploaded ) # don't worry about the non-alphanum characters