# Django how to use post\_save for upload image from another model

**URL:** <https://forum.djangoproject.com/t/django-how-to-use-post-save-for-upload-image-from-another-model/28843>\
**Category:** Using the ORM\
**Created:** [March 8, 2024, 4:04am UTC](https://forum.djangoproject.com/t/django-how-to-use-post-save-for-upload-image-from-another-model/28843 "2024-03-08T04:04:46Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![MDFARHYN](https://sea2.discourse-cdn.com/flex026/user_avatar/forum.djangoproject.com/mdfarhyn/32/4519_2.png) [@MDFARHYN](https://forum.djangoproject.com/u/MDFARHYN)\
**Post date:** [March 8, 2024, 4:04am UTC](https://forum.djangoproject.com/t/django-how-to-use-post-save-for-upload-image-from-another-model/28843/1 "2024-03-08T04:04:46Z")

</div>

I am trying to copy image from my ProductImage models and upload it to my OrderItem models when any new order items will be create but got this error `AttributeError: 'NoneType' object has no attribute 'image'` but you can see my ProductImage model have image fields and also image exits for the current product which order is creating. here my two models:

```auto
#ProductImage Model
class ProductImage(models.Model):
    product = models.ForeignKey(Product,on_delete=models.CASCADE,blank=True,null=True)
    image = models.ImageField(upload_to=dynamic_upload_path)
    thumb_image = models.ImageField(upload_to=dynamic_upload_path,blank=True,null=True)

#OrderItem models

class OrderItem(models.Model):
    order = models.ForeignKey(Order, on_delete=models.CASCADE,blank=True,null=True)
    product = models.ForeignKey(Product, on_delete=models.SET_NULL,blank=True,null=True)
    product_image = models.ForeignKey(ProductImage, on_delete=models.SET_NULL,blank=True,null=True) 
    order_image_file = models.ImageField(blank=True,null=True,upload_to=orderImage_upload_path) 

```

my signals:

```auto
@receiver(post_save, sender=OrderItem)
def OrderItemSignals(sender, instance, created,**kwargs):
    if created:
        instance.order_image_file = instance.product_image.image

```

so basically when any order item will be create I want to fire my post save for copy image from my product image models and upload it to my order item models image fields.

---

<div class="post-metadata">

**Author:** ![antoinehumbert](https://sea2.discourse-cdn.com/flex026/user_avatar/forum.djangoproject.com/antoinehumbert/32/14851_2.png) [@antoinehumbert](https://forum.djangoproject.com/u/antoinehumbert)\
**Post date:** [March 8, 2024, 7:20am UTC](https://forum.djangoproject.com/t/django-how-to-use-post-save-for-upload-image-from-another-model/28843/2 "2024-03-08T07:20:41Z")

</div>

Hi,

Your `OrderItem` model definition allows for `product_image` to be empty (`null=True`), so having it set to `None` may be normal.

Can you share the code where `OrderItem` is created, showing whether a `ProductImage` is affected to the model instance or not.

Also, as it has been said numerous times in this forum, and as it is stated is django documentation (see the first warning at [Signals | Django documentation | Django](https://docs.djangoproject.com/en/5.0/topics/signals/#module-django.dispatch)), you’d rather directly set the `order_image_file` when creating the `OrderItem` instead of using a signal. E.g.: if you do:

```python
OrderItem.objects.create(
    order=some_order,
    product=some_product,
    product_image=some_product_image,
)

```

You’re probably able to do the following:

```python
OrderItem.objects.create(
    order=some_order,
    product=some_product,
    product_image=some_product_image,
    order_image_file=some_product_image.image,
)

```

This would also probably help having a cleaner model definition (without `null=True` on each field which look like weird and may be there just for managing the transiant state of the object between its first _save_ with empty fields and their population by a _post\_save_ signal).

Finally, having the same image as the ProductImage on OrderItem looks like a redundancy. One case where I can see this as useful is when ProductImage.image may change in the future.and we want to keep the image on OrderItem the same as when OrderItem was created. But, in this case, I wonder if the foreign key to ProductImage is necessary!