Fix modification time disappearing from context data and handling mis…

…sing value

CHANGES.rst

@@ -5,6 +5,8 @@ There's a frood who really knows where his towel is.
 
 1.0a10 (unreleased)
 ^^^^^^^^^^^^^^^^^^^
+- Fix modification time disappearing from context data and handling missing value
+  [mhora]
 
 - Show event's start date (instead of publication date) for Event-like objects in Basic, Collection and List tiles.
   [hvelarde]

src/collective/cover/tiles/base.py

@@ -555,7 +555,7 @@ def modified(self):
         mtime = ''
         for k, v in self.context.data.items():
             if INamedImage.providedBy(v):
-                mtime += self.context.data.get('{0}_mtime'.format(k), 0)
+                mtime += self.context.data.get('{0}_mtime'.format(k), '')
 
         return mtime
 

src/collective/cover/tiles/data.py

@@ -46,12 +46,16 @@ def set(self, data):
 
         for k, v in data.items():
             if INamedImage.providedBy(v):
+                mtime_key = '{0}_mtime'.format(k)
                 if (self.key not in self.annotations or
                     k not in self.annotations[self.key] or
                     (self.key in self.annotations and
                      data[k] != self.annotations[self.key][k])):
                     # set modification time of the image
                     notify(Purge(self.tile))
-                    data['{0}_mtime'.format(k)] = '%f' % time.time()
+                    data[mtime_key] = '%f' % time.time()
+                else:
+                    data[mtime_key] = self.annotations[self.key].get(mtime_key, '')
+
         self.annotations[self.key] = PersistentDict(data)
         notify(ObjectModifiedEvent(self.context))