Get a previous historized item by REST request (refs #349)

1 files changed, 34 insertions, 1 deletions

diff --git a/ishtar/furnitures/models.py b/ishtar/furnitures/models.py
index 3571256cf..2fe65b598 100644
--- a/ishtar/furnitures/models.py
+++ b/ishtar/furnitures/models.py
@@ -174,7 +174,40 @@ class BaseHistorizedItem(models.Model):
         super(BaseHistorizedItem, self).save(*args, **kwargs)
         return True
 
+    def get_previous(self, step, strict=True):
+        """
+        Get a "step" previous state of the item
+        """
+        historized = self.history.all()
+        assert len(historized) > step
+        assert not hasattr(historized, '_step')
+        item = historized[step]
+        item._step = step
+        model = self.__class__
+        for k in model._meta.get_all_field_names():
+            field = model._meta.get_field_by_name(k)[0]
+            if hasattr(field, 'rel') and field.rel:
+                if not hasattr(item, k+'_id'):
+                    setattr(item, k, getattr(self, k))
+                    continue
+                val = getattr(item, k+'_id')
+                if not val:
+                    setattr(item, k, None)
+                    continue
+                try:
+                    val = field.rel.to.objects.get(pk=val)
+                    setattr(item, k, val)
+                except ObjectDoesNotExist:
+                    if strict:
+                        raise HistoryError(u"The class %s has no pk %d" % (
+                                           unicode(field.rel.to), val))
+                    setattr(item, k, None)
+        return item
+
     def rollback(self, date):
+        """
+        Rollback to a previous state
+        """
         to_del, new_item = [], None
         for item in self.history.all():
             to_del.append(item)
@@ -193,7 +226,7 @@ class BaseHistorizedItem(models.Model):
             self.save()
         except:
             raise HistoryError(u"The rollback has failed.")
-        # clean the non necessary steps
+        # clean the obsolete history
         for historized_item in to_del:
             historized_item.delete()