Django覆盖保存为模型
保存模型之前,我需要重新调整图片大小。但是,如何检查是否添加了新图片或仅更新了说明,以便每次保存模型时都可以跳过重新缩放?
class Model(model.Model): image=models.ImageField(upload_to='folder')
thumb=models.ImageField(upload_to='folder')
description=models.CharField()
def save(self, *args, **kwargs):
if self.image:
small=rescale_image(self.image,width=100,height=100)
self.image_small=SimpleUploadedFile(name,small_pic)
super(Model, self).save(*args, **kwargs)
我只想在加载新图像或更新图像时重新缩放,而在描述更新时不想要。
回答:
一些想法:
class Model(model.Model): _image=models.ImageField(upload_to='folder')
thumb=models.ImageField(upload_to='folder')
description=models.CharField()
def set_image(self, val):
self._image = val
self._image_changed = True
# Or put whole logic in here
small = rescale_image(self.image,width=100,height=100)
self.image_small=SimpleUploadedFile(name,small_pic)
def get_image(self):
return self._image
image = property(get_image, set_image)
# this is not needed if small_image is created at set_image
def save(self, *args, **kwargs):
if getattr(self, '_image_changed', True):
small=rescale_image(self.image,width=100,height=100)
self.image_small=SimpleUploadedFile(name,small_pic)
super(Model, self).save(*args, **kwargs)
不知道它是否可以在所有伪自动django工具中正常运行(例如:ModelForm,contrib.admin等)。
以上是 Django覆盖保存为模型 的全部内容, 来源链接: utcz.com/qa/398462.html