participants: added support for year of birth

dav_events/models/participant.py

@@ -28,6 +28,7 @@ class AbstractParticipant(models.Model):
     email_address = models.EmailField(verbose_name=_('E-Mail-Adresse'))
     phone_number = models.CharField(max_length=254,
                                     verbose_name=_('Telefonnummer'))
+    year_of_birth = models.IntegerField(verbose_name=_('Geburtsjahr'))
     dav_member = models.BooleanField(default=True,
                                      verbose_name=_('DAV Mitglied'),
                                      help_text=_('In Ausnahmefällen nehmen wir auch Nichtmitglieder mit.'))
@@ -48,6 +49,11 @@ class AbstractParticipant(models.Model):
 
     purge_at = models.DateTimeField()
 
+    def approx_age(self):
+        now = datetime.datetime.now()
+        year_now = now.year
+        return year_now - self.year_of_birth
+
     class Meta:
         abstract = True
 
@@ -62,6 +68,7 @@ class AbstractParticipant(models.Model):
     {address}, {postal_code} {city}
 
     DAV Mitglied: {dav_info}
+    Jahrgang: {year_of_birth} (ungefähres Alter: {approx_age})
 
     Notfallkontakt:
     {emergency_contact}
@@ -80,6 +87,8 @@ class AbstractParticipant(models.Model):
                 postal_code=self.postal_code,
                 city=self.city,
                 dav_info=dav_info,
+                year_of_birth=self.year_of_birth,
+                approx_age=self.approx_age(),
                 emergency_contact=self.emergency_contact,
                 note=self.note,
             )