1 files changed, 34 insertions, 4 deletions
diff --git a/ishtar_common/models.py b/ishtar_common/models.py
index c7223c898..e5e173654 100644
--- a/ishtar_common/models.py
+++ b/ishtar_common/models.py
@@ -148,6 +148,18 @@ class ValueGetter(object):
         return values
 
 
+class HistoryModel(models.Model):
+    class Meta:
+        abstract = True
+
+    def m2m_listing(self, key):
+        hist_value = getattr(self, "historical_" + key, None)
+        if not hist_value:
+            return
+        related_model = getattr(self, key).model
+        return related_model.history_decompress(hist_value)
+
+
 class HistoricalRecords(BaseHistoricalRecords):
     def create_historical_record(self, instance, type):
         try:
@@ -523,9 +535,9 @@ class GeneralType(Cached, models.Model):
         return self.txt_idx
 
     @classmethod
-    def history_decompress(cls, value=""):
+    def history_decompress(cls, value, create=False):
         if not value:
-            value = ""
+            return []
         res = []
         for txt_idx in value.split(HISTORY_M2M_SPLIT):
             try:
@@ -1571,12 +1583,27 @@ class BaseHistorizedItem(DocumentItem, FullSearch, Imported, JsonData,
         if not new_item:
             raise HistoryError(u"The date to rollback to doesn't exist.")
         try:
-            for f in self._meta.fields:
-                k = f.name
+            field_keys = [f.name for f in self._meta.fields]
+            for k in field_keys:
                 if k != 'id' and hasattr(self, k):
                     if not hasattr(new_item, k):
                         k = k + "_id"
                     setattr(self, k, getattr(new_item, k))
+
+                # M2M history
+                if k.startwith('historical_') \
+                        and k[len('historical_'):] in field_keys:
+                    value = getattr(new_item, k)
+                    if not value:
+                        continue
+                    base_k = k[len('historical_'):]
+                    base_field = self._meta.get_field(base_k)
+                    base_field.clear()
+                    new_values = base_field.related_model.history_decompress(
+                        value, create=True
+                    )
+                    for val in new_values:
+                        base_field.add(val)
             try:
                 self.history_modifier = User.objects.get(
                     pk=new_item.history_modifier_id)
@@ -1591,6 +1618,9 @@ class BaseHistorizedItem(DocumentItem, FullSearch, Imported, JsonData,
         for historized_item in to_del:
             historized_item.delete()
 
+    def m2m_listing(self, key):
+        return getattr(self, key).all()
+
     def values(self):
         values = {}
         for f in self._meta.fields: