Django覆盖保存
问题描述:
我想在我的模型中覆盖保存方法来创建合适的slug并在其中进行小修改来创建imagefield副本。我该如何处理?Django覆盖保存
def save(self, *args, **kwargs):
super(MyModel, self).save(*args, **kwargs) #to get id
#slug
self.slug = '%s-%i' % (self.topic, self.id)
#create copy of img
cp_path = dirname(self.image.path)+'/copies_'+basename(self.image.path)
shutil.copy2(self.image.path, cp_path)
file = open(cp_path)
django_file = File(file)
django_file.name = basename(cp_path) #otherwise path will be duplicated
self.cp_image = django_file
super(MyModel, self).save(*args, **kwargs) #to save my new ImageField
create_watermark(self.cp_image, self.topic, self.text, 500, 45)
原因我使用super(MyModel,self).save()两次我有一个self.image文件的副本。正如你所看到的,我对django和python不是很熟悉。我该如何做得更好?
答
它可能不是最优雅的方式,但您可以尝试将save()
与post_save
signal结合使用。大概是这个样子:
class MyModel(Model):
## Stuff
def save(self, *args, **kwargs):
#create copy of img. Fixed up to use string formatting.
cp_path = "%s/copies_%s" %
(dirname(self.image.path), basename(self.image.path))
shutil.copy2(self.image.path, cp_path)
file = open(cp_path)
django_file = File(file)
django_file.name = basename(cp_path)
self.cp_image = django_file
create_watermark(self.cp_image, self.topic, self.text, 500, 45)
super(MyModel, self).save(*args, **kwargs) #to save my new ImageField
from django.dispatch import receiver
from django.db.models.signals import post_save
@receiver(post_save, sender=MyModel)
def mymodel_slug_handler(sender, instance=None, **kwargs):
if instance is not None:
new_slug = '%s-%i' % (instance.topic, instance.id)
if instance.slug != new_slug: # Stops recursion.
instance.slug = new_slug
instance.save()
不幸的是它会导致“没有这样的文件或目录:”错误如果我不会用save()方法之前,我尝试对文件进行操作。 – MilkyWay 2011-05-03 19:54:39
哦,然后将整个保存移动到post_save处理程序。这也可以让你检查created = True只做一次。 – 2011-05-03 20:38:34