Django - Cannot create migrations for ImageField with dynamic upload_to value

Question

I just upgraded my app to 1.7 (actually still trying).

This is what i had in models.py:

def path_and_rename(path):
    def wrapper(instance, filenam         


        

Answer 1

You can create function with kwargs like this:

def upload_image_location(instance, filename, thumbnail=False):
    name, ext = os.path.splitext(filename)
    path = f'news/{instance.slug}{f"_thumbnail" if thumbnail else ""}{ext}'
    n = 1
    while os.path.exists(path):
        path = f'news/{instance.slug}-{n}{ext}'
        n += 1
    return path

and use this method with functools.partial in your model:

image = models.ImageField(
    upload_to=upload_image_location,
    width_field='image_width',
    height_field='image_height'
)
thumbnail_image = models.ImageField(upload_to=partial(upload_image_location, thumbnail=True), blank=True)

You will get migration like this:

class Migration(migrations.Migration):

    dependencies = [
        ('news', '0001_initial'),
    ]

    operations = [
        migrations.AddField(
            model_name='news',
            name='thumbnail_image',
            field=models.ImageField(blank=True, upload_to=functools.partial(news.models.upload_image_location, *(), **{'thumbnail': True})),
        ),
        migrations.AlterField(
            model_name='news',
            name='image',
            field=models.ImageField(height_field='image_height', upload_to=news.models.upload_image_location, width_field='image_width'),
        ),
    ]