breccia-mapper/people/migrations/0036_move_latlng_to_answerset.py

# Generated by Django 2.2.10 on 2021-02-24 15:29

from django.core.exceptions import ObjectDoesNotExist
from django.db import migrations, models


def migrate_forward(apps, schema_editor):
    Organisation = apps.get_model('people', 'Organisation')

    fields = {
        'latitude',
        'longitude',
    }

    for obj in Organisation.objects.all():
        try:
            answer_set = obj.answer_sets.last()
            if answer_set is None:
                raise ObjectDoesNotExist

        except ObjectDoesNotExist:
            answer_set = obj.answer_sets.create()

        for field in fields:
            value = getattr(obj, field)
            try:
                setattr(answer_set, field, value)

            except TypeError:
                # Cannot directly set an m2m field
                m2m = getattr(answer_set, field)
                m2m.set(value.all())

        answer_set.save()


def migrate_backward(apps, schema_editor):
    Organisation = apps.get_model('people', 'Organisation')

    fields = {
        'latitude',
        'longitude',
    }

    for obj in Organisation.objects.all():
        try:
            answer_set = obj.answer_sets.last()

            for field in fields:
                value = getattr(answer_set, field)
                try:
                    setattr(obj, field, value)

                except TypeError:
                    # Cannot directly set an m2m field
                    m2m = getattr(obj, field)
                    m2m.set(value.all())

            obj.save()

        except ObjectDoesNotExist:
            pass


class Migration(migrations.Migration):

    dependencies = [
        ('people', '0035_add_organisation_questions'),
    ]

    operations = [
        migrations.AddField(
            model_name='organisationanswerset',
            name='latitude',
            field=models.FloatField(blank=True, null=True),
        ),
        migrations.AddField(
            model_name='organisationanswerset',
            name='longitude',
            field=models.FloatField(blank=True, null=True),
        ),
        migrations.RunPython(migrate_forward, migrate_backward),
        migrations.RemoveField(
            model_name='organisation',
            name='latitude',
        ),
        migrations.RemoveField(
            model_name='organisation',
            name='longitude',
        ),
    ]