Migrate to filer ThumbnailOption

0000_README.rst

1. Add the discovery of proper ThumbnailOption model in you app models.py
2. Create a manual migration like in example_migration.py

3. In every migration (even existing ones) add:

   from custom_plugins.models import thumbnail_model

4. In every migration (even existing ones) replace 'cmsplugin_filer_image.ThumbnailOption' with thumbnail_model like here https://github.com/nephila/djangocms-blog/blob/develop/djangocms_blog/migrations/0001_initial.py#L12 -> https://github.com/nephila/djangocms-blog/blob/develop/djangocms_blog/migrations/0001_initial.py#L108

example_migration.py

# -*- coding: utf-8 -*-
# This migration must be created manually
from __future__ import unicode_literals

from django.db import migrations, models
from custom_plugins.models import thumbnail_model


class Migration(migrations.Migration):

    if 'cmsplugin_filer' not in thumbnail_model:
        dependencies = [
            ('custom_plugins', 'PREVIOUS_MIGRATION'),
            ('filer', '0003_thumbnailoption'),
            ('cmsplugin_filer_image', '0003_mv_thumbnail_option_to_filer_20160119_1720'),
        ]
        run_before = [
            ('cmsplugin_filer_image', '0004_auto_20160120_0950'),
        ]
    else:
        dependencies = [
            ('filer', '__first__'),
            ('cmsplugin_filer_image', '__first__'),
            ('custom_plugins', 'PREVIOUS_MIGRATION'),
        ]

    operations = [
        migrations.AlterField(
            model_name='MyModel',  ## Add your model name
            name='ThumbnailOptionField',  ## Add your field name
            field=models.ForeignKey(related_name='MyRelatedName',
                                    verbose_name='Main image full', blank=True,
                                    to=thumbnail_model, null=True),
        ),
        ...
    ]

models.py

# -*- coding: utf-8 -*-

import foo
...

try:
    from cmsplugin_filer_image.models import ThumbnailOption  # NOQA
except ImportError:
    from filer.models import ThumbnailOption  # NOQA


thumbnail_model = '%s.%s' % (
    ThumbnailOption._meta.app_label, ThumbnailOption.__name__
)