Manage link between import and imported object - Auto-delete imported object when deleting import

1 files changed, 34 insertions, 2 deletions

diff --git a/ishtar_common/models.py b/ishtar_common/models.py
index c7f89299e..23c2f3ac7 100644
--- a/ishtar_common/models.py
+++ b/ishtar_common/models.py
@@ -40,7 +40,7 @@ from django.core.validators import validate_slug
 from django.core.urlresolvers import reverse, NoReverseMatch
 from django.db.utils import DatabaseError
 from django.db.models import Q, Max, Count
-from django.db.models.signals import post_save
+from django.db.models.signals import post_save, pre_delete
 from django.utils.translation import ugettext_lazy as _, ugettext
 from django.utils.safestring import SafeUnicode, mark_safe
 from django.template.defaultfilters import slugify
@@ -78,6 +78,12 @@ def post_save_user(sender, **kwargs):
         pass
 post_save.connect(post_save_user, sender=User)
 
+class Imported(models.Model):
+    imports = models.ManyToManyField('Import', blank=True, null=True,
+                    related_name="imported_%(app_label)s_%(class)s")
+    class Meta:
+        abstract = True
+
 class ValueGetter(object):
     _prefix = ""
     def get_values(self, prefix=''):
@@ -473,7 +479,7 @@ class HistoryError(Exception):
     def __str__(self):
         return repr(self.value)
 
-class BaseHistorizedItem(models.Model):
+class BaseHistorizedItem(Imported):
     history_modifier = models.ForeignKey(User, related_name='+',
                               on_delete=models.SET_NULL,
                               verbose_name=_(u"Last editor"), blank=True,
@@ -1425,6 +1431,32 @@ class Import(models.Model):
         self.state = 'AC'
         self.save()
 
+    def get_all_imported(self):
+        print(dir(self._meta))
+        imported = []
+        for related, zorg in self._meta.get_all_related_m2m_objects_with_model():
+            accessor = related.get_accessor_name()
+            imported += [(accessor, obj)
+                         for obj in getattr(self, accessor).all()]
+        return imported
+
+def pre_delete_import(sender, **kwargs):
+    # deleted imported items when an import is delete
+    instance = kwargs.get('instance')
+    if not instance:
+        return
+    to_delete = []
+    for accessor, imported in instance.get_all_imported():
+        # if imported is related to another import do not delete
+        if getattr(instance, accessor).exclude(pk=imported.pk).count():
+            continue
+        to_delete.append(imported)
+    for item in to_delete:
+        item.delete()
+
+
+pre_delete.connect(pre_delete_import, sender=Import)
+
 class Organization(Address, Merge, OwnPerms, ValueGetter):
     TABLE_COLS = ('name', 'organization_type',)
     name = models.CharField(_(u"Name"), max_length=300)