Question

I have a model that I want to save in Django Admin

class Product(models.Model):
    # other fields
    img1 = models.ImageField(upload_to='%s/%s/1/large/' % (category, prod_no))
    img1_thumb = models.ImageField(upload_to='%s/%s/1/thumbnail/' % (category, prod_no), editable=False)

    def save(self, *args, **kwargs):
        newImg1  = resizeImg(self.img1, (75, 112))
        self.img1_thumb = newImg1
        super(Product, self).save(*args, **kwargs)

The resize image function

def resizeImg(image, size):
    try:
        if imghdr.what(image) == 'jpeg':
            img = Image.open(image)
            img.thumbnail(size, Image.ANTIALIAS)

            # this is how to save the img
            # img.save(filename + '.jpg', 'JPEG', quality=75)

            return img
        else:
            return 'not_jpg'

    except Exception, e:
        return 'exception'

Saving this in Django Admin creates this error

AttributeError at /admin/myapp/product/add/
_committed

UPDATE – full traceback:

Environment:


Request Method: POST
Request URL: http://127.0.0.1:8000/admin/myapp/product/add/

Django Version: 1.3.1
Python Version: 2.7.1
Installed Applications:
['django.contrib.auth',
 'django.contrib.contenttypes',
 'django.contrib.sessions',
 'django.contrib.sites',
 'django.contrib.messages',
 'django.contrib.staticfiles',
 'django.contrib.admin',
 'bc']
Installed Middleware:
('django.middleware.common.CommonMiddleware',
 'django.contrib.sessions.middleware.SessionMiddleware',
 'django.middleware.csrf.CsrfViewMiddleware',
 'django.middleware.csrf.CsrfResponseMiddleware',
 'django.contrib.auth.middleware.AuthenticationMiddleware',
 'django.contrib.messages.middleware.MessageMiddleware')


Traceback:
File "/Library/Python/2.7/site-packages/django/core/handlers/base.py" in get_response
  111.                         response = callback(request, *callback_args, **callback_kwargs)
File "/Library/Python/2.7/site-packages/django/contrib/admin/options.py" in wrapper
  307.                 return self.admin_site.admin_view(view)(*args, **kwargs)
File "/Library/Python/2.7/site-packages/django/utils/decorators.py" in _wrapped_view
  93.                     response = view_func(request, *args, **kwargs)
File "/Library/Python/2.7/site-packages/django/views/decorators/cache.py" in _wrapped_view_func
  79.         response = view_func(request, *args, **kwargs)
File "/Library/Python/2.7/site-packages/django/contrib/admin/sites.py" in inner
  197.             return view(request, *args, **kwargs)
File "/Library/Python/2.7/site-packages/django/utils/decorators.py" in _wrapper
  28.             return bound_func(*args, **kwargs)
File "/Library/Python/2.7/site-packages/django/utils/decorators.py" in _wrapped_view
  93.                     response = view_func(request, *args, **kwargs)
File "/Library/Python/2.7/site-packages/django/utils/decorators.py" in bound_func
  24.                 return func(self, *args2, **kwargs2)
File "/Library/Python/2.7/site-packages/django/db/transaction.py" in inner
  217.                 res = func(*args, **kwargs)
File "/Library/Python/2.7/site-packages/django/contrib/admin/options.py" in add_view
  882.                 self.save_model(request, new_object, form, change=False)
File "/Library/Python/2.7/site-packages/django/contrib/admin/options.py" in save_model
  665.         obj.save()
File "/Users/rocky/Projects/BestChoose/bc/models.py" in save
  66.         super(Product, self).save(*args, **kwargs)
File "/Library/Python/2.7/site-packages/django/db/models/base.py" in save
  460.         self.save_base(using=using, force_insert=force_insert, force_update=force_update)
File "/Library/Python/2.7/site-packages/django/db/models/base.py" in save_base
  543.                         for f in meta.local_fields if not isinstance(f, AutoField)]
File "/Library/Python/2.7/site-packages/django/db/models/fields/files.py" in pre_save
  253.         if file and not file._committed:
File "/Library/Python/2.7/site-packages/PIL-1.1.7-py2.7-macosx-10.7-intel.egg/Image.py" in __getattr__
  512.         raise AttributeError(name)

Exception Type: AttributeError at /admin/myapp/product/add/
Exception Value: _committed

Answer 1

You cannot do this:

newImg1  = resizeImg(self.img1, (75, 112))
self.img1_thumb = newImg1

You are assigning an Image to a field that expects a File. You need to first create a file from the image. Instead of typing it all out again, please see this snippet that details the right way.

You can also use any of the thumbnailing applications available to simplify your code. solr-thumbnail is one of the most popular.