Resolve "[Info mailings] sent_to works globally instead of per event"

Closes #20 (closed)

aleksis/apps/paweljong/migrations/0014_move_sent_to_to_through.py

+# Generated by Django 3.2.12 on 2022-03-02 19:50
+
+import django.contrib.sites.managers
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+def migrate_to_new_through(apps, schema_editor):
+    Event = apps.get_model("paweljong", "Event")
+    EventRegistration = apps.get_model("paweljong", "EventRegistration")
+    Through = apps.get_model("paweljong", "EventInfoMailingThrough")
+
+    db_alias = schema_editor.connection.alias
+
+    for through_old in Event.info_mailings.through.objects.all():
+        event = through_old.event
+        info_mailing = through_old.infomailing
+
+        through = Through.objects.create(event=event, info_mailing=info_mailing)
+        for person in info_mailing.sent_to.all():
+            if EventRegistration.objects.filter(person_id=person.id, event_id=event.id).exists():
+                through.sent_to.add(person)
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('core', '0035_preference_model_unique'),
+        ('sites', '0002_alter_domain_unique'),
+        ('paweljong', '0013_info_mailings'),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name='EventInfoMailingThrough',
+            fields=[
+                ('id', models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('extended_data', models.JSONField(default=dict, editable=False)),
+                ('event', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, to='paweljong.event')),
+                ('info_mailing', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, to='paweljong.infomailing')),
+                ('sent_to', models.ManyToManyField(blank=True, editable=False, related_name='received_info_mailings', to='core.Person', verbose_name='Sent to persons')),
+                ('site', models.ForeignKey(default=1, editable=False, on_delete=django.db.models.deletion.CASCADE, to='sites.site')),
+            ],
+            options={
+                'abstract': False,
+            },
+            managers=[
+                ('objects', django.contrib.sites.managers.CurrentSiteManager()),
+            ],
+        ),
+        migrations.AddField(
+            model_name='event',
+            name='info_mailings_new',
+            field=models.ManyToManyField(blank=True, related_name='events', through='paweljong.EventInfoMailingThrough', to='paweljong.InfoMailing', verbose_name='Info mailings'),
+        ),
+        migrations.RunPython(migrate_to_new_through),
+        migrations.RemoveField(
+            model_name='event',
+            name='info_mailings',
+        ),
+        migrations.RenameField(
+            'event',
+            'info_mailings_new',
+            'info_mailings',
+        ),
+        migrations.RemoveField(
+            model_name='infomailing',
+            name='sent_to',
+        ),
+    ]