Exception Value: 'Image' object has no attribute 'closed'

[thelittlebug]

Hello,

I am trying to add a thumbnail to the django admin list display as described in the docs.

My installed packages:

Django                     2.1.4     
django-filer               1.4.1     
django-imagekit            4.0.2     
pilkit                     2.0       
Pillow                     5.3.0     

My model and the admin config:

from django.db import models
from filer.fields.image import FilerImageField
from imagekit.models import ImageSpecField
from imagekit.processors import ResizeToFit

class Trainer(models.Model):
    name = models.CharField(max_length=100)
    picture = FilerImageField(
        null=True,
        blank=True,
        related_name="picture_trainer",
        on_delete=models.CASCADE
    )
    picture_admin_thumbnail = ImageSpecField(
        source='picture',
        processors=[ResizeToFit(120)],
        format='JPEG',
        options={'quality': 70}
    )
    quote = models.CharField(max_length=200)
    experience = models.CharField(max_length=500)
    education = models.CharField(max_length=500)

    created_at = models.DateTimeField(auto_now_add=True)
    updated_at = models.DateTimeField(auto_now=True)

from django.contrib import admin
from imagekit.admin import AdminThumbnail

from .models import Trainer

class TrainerAdmin(admin.ModelAdmin):
    list_display = (
        '__str__',
        'picture_thumbnail',
        'name',
        'created_at',
        'updated_at'
    )
    picture_thumbnail = AdminThumbnail(image_field='picture_admin_thumbnail')
    readonly_fields = ['picture_thumbnail']

admin.site.register(Trainer, TrainerAdmin)

on my own im not able to figure out why it throws this error. any help would be of great value.

thx :)

[vstoykov]

Thank you for reporting the problem.

It would be good if you provided the traceback of the error in order to see where it was raised.

Nevertheless from what I know FilerImageField is actually foreign key to a model instead of a real ImageField which means that picture attribute will be Model instance instead of something extending ImageFile or at least File. The actual file from django-filer in your case is picture.file.

In order to fix this probably you should need to make a getter property in your model. For example something like:

@property
def picture_file(self):
    return picture.file

Or something similar and then use source='picture_file'.

This is untested it just came in my mind but you can try it.

[thelittlebug]

thank you for your valuable input on this problem.

i was unable to debug it on my own because i had no real debugging possibility till now (it's not so easy to debug django and all possible external and internal python modules as a django newcomer without a good configured dev-environment. maybe i should write a little "howto: debug django and other little monsters, the comfortably way" ).

i'll try your idea in the next few days.

many thx

[thelittlebug]

thank you, works as expected :)

@property
def picture_file(self):
    return self.picture.file