virtual agendas: allow direct relation from agenda to timeperiod (#40058)

chrono/agendas/migrations/0040_timeperiod_agenda.py

@@ -0,0 +1,33 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.11.18 on 2020-02-26 13:27
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('agendas', '0039_booking_delays'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='timeperiod',
+            name='agenda',
+            field=models.ForeignKey(
+                null=True,
+                on_delete=django.db.models.deletion.CASCADE,
+                related_name='excluded_timeperiods',
+                to='agendas.Agenda',
+            ),
+        ),
+        migrations.AlterField(
+            model_name='timeperiod',
+            name='desk',
+            field=models.ForeignKey(
+                null=True, on_delete=django.db.models.deletion.CASCADE, to='agendas.Desk'
+            ),
+        ),
+    ]

chrono/agendas/models.py

@@ -326,7 +326,10 @@ class TimePeriod(models.Model):
     weekday = models.IntegerField(_('Week day'), choices=WEEKDAYS_LIST)
     start_time = models.TimeField(_('Start'))
     end_time = models.TimeField(_('End'))
-    desk = models.ForeignKey('Desk', on_delete=models.CASCADE)
+    desk = models.ForeignKey('Desk', on_delete=models.CASCADE, null=True)
+    agenda = models.ForeignKey(
+        Agenda, on_delete=models.CASCADE, null=True, related_name='excluded_timeperiods'
+    )
 
     class Meta:
         ordering = ['weekday', 'start_time']
@@ -338,6 +341,11 @@ class TimePeriod(models.Model):
             date_format(self.end_time, 'TIME_FORMAT'),
         )
 
+    def save(self, *args, **kwargs):
+        if self.agenda:
+            assert self.agenda.kind == 'virtual', "a time peŕiod can only reference a virtual agenda"
+        super(TimePeriod, self).save(*args, **kwargs)
+
     @property
     def weekday_str(self):
         return WEEKDAYS[self.weekday]