boards/migrations/0047_attachment_alias.py

# -*- coding: utf-8 -*-
# Generated by Django 1.9.5 on 2016-05-21 07:43
from __future__ import unicode_literals

from boards.signals import generate_thumb
from boards.utils import get_extension
from django.db import migrations, models


class Migration(migrations.Migration):

    def images_to_attachments(apps, schema_editor):
        PostImage = apps.get_model('boards', 'PostImage')
        Attachment = apps.get_model('boards', 'Attachment')

        count = 0
        images = PostImage.objects.all()
        for image in images:
            file_type = get_extension(image.image.name)
            attachment = Attachment.objects.create(
                file=image.image.file, mimetype=file_type, hash=image.hash,
                alias=image.alias)
            generate_thumb(attachment)
            count += 1
            print('Processed {} of {} images'.format(count, len(images)))
            for post in image.post_images.all():
                post.attachments.add(attachment)

                image.image.close()

    dependencies = [
        ('boards', '0046_auto_20160520_2307'),
    ]

    operations = [
        migrations.AddField(
            model_name='attachment',
            name='alias',
            field=models.TextField(blank=True, null=True, unique=True),
        ),
        migrations.RunPython(images_to_attachments),
    ]