Added at_idmapper_flush to allow objects more control of their flush characteristics.

evennia/typeclasses/attributes.py

@@ -325,6 +325,14 @@ class AttributeHandler(object):
         self._catcache.pop(catkey, None)
         self._cache_complete = False
 
+    def reset_cache(self):
+        """
+        Reset cache from the outside.
+        """
+        self._cache_complete = False
+        self._cache = {}
+        self._catcache = {}
+
     def has(self, key=None, category=None):
         """
         Checks if the given Attribute (or list of Attributes) exists on
@@ -910,7 +918,6 @@ class NAttributeHandler(object):
 
         """
         self._store[key] = value
-        self.obj.set_recache_protection()
 
     def remove(self, key):
         """
@@ -922,7 +929,6 @@ class NAttributeHandler(object):
         """
         if key in self._store:
             del self._store[key]
-        self.obj.set_recache_protection(self._store)
 
     def clear(self):
         """

evennia/typeclasses/models.py

@@ -376,6 +376,27 @@ class TypedObject(SharedMemoryModel):
         raise Exception("dbref cannot be deleted!")
     dbref = property(__dbref_get, __dbref_set, __dbref_del)
 
+    def at_idmapper_flush(self):
+        """
+        This is called when the idmapper cache is flushed and
+        allows customized actions when this happens.
+
+        Returns:
+            do_flush (bool): If True, flush this object as normal. If
+                False, don't flush and expect this object to handle
+                the flushing on its own.
+
+        """
+        if self.nattributes.all():
+            # we can't flush this object if we have non-persistent
+            # attributes stored - those would get lost! Nevertheless
+            # we try to flush as many references as we can.
+            self.attributes.reset_cache()
+            self.tags.reset_cache()
+            return False
+        # a normal flush
+        return True
+
     #
     # Object manipulation methods
     #

evennia/typeclasses/tags.py

@@ -212,6 +212,13 @@ class TagHandler(object):
         self._catcache.pop(catkey, None)
         self._cache_complete = False
 
+    def reset_cache(self):
+        """
+        Reset the cache from the outside.
+        """
+        self._cache_complete = False
+        self._cache = {}
+        self._catcache = {}
 
     def add(self, tag=None, category=None, data=None):
         """