1 files changed, 19 insertions, 0 deletions
diff --git a/archaeological_context_records/models.py b/archaeological_context_records/models.py
index a8c6a1dcc..9a4fa7880 100644
--- a/archaeological_context_records/models.py
+++ b/archaeological_context_records/models.py
@@ -19,6 +19,7 @@
 
 from django.conf import settings
 from django.contrib.gis.db import models
+from django.core.exceptions import ValidationError
 from django.core.urlresolvers import reverse
 from django.utils.translation import ugettext_lazy as _, ugettext, pgettext
 
@@ -252,6 +253,24 @@ class RelationType(GeneralType):
         verbose_name_plural = _(u"Relation types")
         ordering = ('order',)
 
+    def clean(self):
+        # cannot have symmetrical and an inverse_relation
+        if self.symmetrical and self.inverse_relation:
+            raise ValidationError(
+                        _(u"Cannot have symmetrical and an inverse_relation"))
+
+    def save(self, *args, **kwargs):
+        obj = super(RelationType, self).save(*args, **kwargs)
+        # after saving check that the inverse_relation of the inverse_relation
+        # point to the saved object
+        if self.inverse_relation \
+           and (not self.inverse_relation.inverse_relation
+                or self.inverse_relation.inverse_relation != self):
+            self.inverse_relation.inverse_relation = self
+            self.inverse_relation.symmetrical = False
+            self.inverse_relation.save()
+        return obj
+
 class RecordRelations(models.Model):
     left_record = models.ForeignKey(ContextRecord,
                                     related_name='left_relations')