Work on M2M historization

1 files changed, 33 insertions, 2 deletions

diff --git a/archaeological_context_records/models.py b/archaeological_context_records/models.py
index 82527acb1..cce36236c 100644
--- a/archaeological_context_records/models.py
+++ b/archaeological_context_records/models.py
@@ -17,12 +17,12 @@
 
 # See the file COPYING for details.
 
-import time
+import datetime
 
 from django.conf import settings
 from django.contrib.gis.db import models
 from django.core.urlresolvers import reverse
-from django.db import connection, transaction
+from django.db import connection
 from django.db.models import Q
 from django.db.models.signals import post_delete, post_save, m2m_changed
 from django.utils.translation import ugettext_lazy as _, pgettext, \
@@ -84,6 +84,37 @@ class Dating(models.Model):
             return unicode(self.period)
         return u"%s (%s-%s)" % (self.period, start_date, end_date)
 
+    SEP = u"$|£|$"
+    HISTORY_ATTR = ["period", "start_date", "end_date", "dating_type",
+                    "quality", "precise_dating"]
+
+    def history_compress(self):
+        values = []
+        for attr in self.HISTORY_ATTR:
+            val = getattr(self, attr)
+            if hasattr(val, 'history_compress'):
+                values.append(val.history_compress())
+            elif hasattr(val, 'isoformat'):
+                values.append(val.isoformat())
+            else:
+                values.append(unicode(val))
+        return self.SEP.join(values)
+
+    @classmethod
+    def history_decompress(cls, value):
+        if not value:
+            value = ""
+        res = {}
+        for idx, val in enumerate(value.split(cls.SEP)):
+            key = cls.HISTORY_ATTR[idx]
+            if key in ("period", "dating_type", "quality"):
+                field = cls._meta.get_field(key)
+                val = field.to.model.objects.get(txt_idx=val)
+            elif key in ("start_date", "end_date"):
+                val = datetime.datetime.fromisoformat(val)
+            res[key] = val
+        return res
+
     @classmethod
     def is_identical(cls, dating_1, dating_2):
         """