--- a/cwvreg.py	Thu May 20 20:47:13 2010 +0200
+++ b/cwvreg.py	Thu May 20 20:47:55 2010 +0200
@@ -82,7 +82,6 @@
 .. automethod:: cubicweb.cwvreg.CubicWebVRegistry.register_all
 .. automethod:: cubicweb.cwvreg.CubicWebVRegistry.register_and_replace
 .. automethod:: cubicweb.cwvreg.CubicWebVRegistry.register
-.. automethod:: cubicweb.cwvreg.CubicWebVRegistry.register_if_interface_found
 .. automethod:: cubicweb.cwvreg.CubicWebVRegistry.unregister
 
 Examples:
@@ -192,6 +191,8 @@
 __docformat__ = "restructuredtext en"
 _ = unicode
 
+from warnings import warn
+
 from logilab.common.decorators import cached, clear_cache
 from logilab.common.deprecation import  deprecated
 from logilab.common.modutils import cleanup_sys_modules
@@ -211,23 +212,23 @@
 
 def use_interfaces(obj):
     """return interfaces used by the given object by searching for implements
-    selectors, with a bw compat fallback to accepts_interfaces attribute
+    selectors
     """
     from cubicweb.selectors import implements
-    try:
-        # XXX deprecated
-        return sorted(obj.accepts_interfaces)
-    except AttributeError:
-        try:
-            impl = obj.__select__.search_selector(implements)
-            if impl:
-                return sorted(impl.expected_ifaces)
-        except AttributeError:
-            pass # old-style appobject classes with no accepts_interfaces
-        except:
-            print 'bad selector %s on %s' % (obj.__select__, obj)
-            raise
-        return ()
+    impl = obj.__select__.search_selector(implements)
+    if impl:
+        return sorted(impl.expected_ifaces)
+    return ()
+
+def require_appobject(obj):
+    """return interfaces used by the given object by searching for implements
+    selectors
+    """
+    from cubicweb.selectors import appobject_selectable
+    impl = obj.__select__.search_selector(appobject_selectable)
+    if impl:
+        return (impl.registry, impl.regids)
+    return None
 
 
 class CWRegistry(Registry):
@@ -477,6 +478,7 @@
     def reset(self):
         super(CubicWebVRegistry, self).reset()
         self._needs_iface = {}
+        self._needs_appobject = {}
         # two special registries, propertydefs which care all the property
         # definitions, and propertyvals which contains values for those
         # properties
@@ -536,6 +538,7 @@
                 for obj in objects:
                     obj.schema = schema
 
+    @deprecated('[3.9] use .register instead')
     def register_if_interface_found(self, obj, ifaces, **kwargs):
         """register `obj` but remove it if no entity class implements one of
         the given `ifaces` interfaces at the end of the registration process.
@@ -561,7 +564,15 @@
         # XXX bw compat
         ifaces = use_interfaces(obj)
         if ifaces:
+            if not obj.__name__.endswith('Adapter') and \
+                   any(iface for iface in ifaces if not isinstance(iface, basestring)):
+                warn('[3.9] %s: interfaces in implements selector are '
+                     'deprecated in favor of adapters / appobject_selectable '
+                     'selector' % obj.__name__, DeprecationWarning)
             self._needs_iface[obj] = ifaces
+        depends_on = require_appobject(obj)
+        if depends_on is not None:
+            self._needs_appobject[obj] = depends_on
 
     def register_objects(self, path, force_reload=False):
         """overriden to remove objects requiring a missing interface"""
@@ -578,13 +589,18 @@
         # we may want to keep interface dependent objects (e.g.for i18n
         # catalog generation)
         if self.config.cleanup_interface_sobjects:
-            # remove appobjects that don't support any available interface
+            # XXX deprecated with cw 3.9: remove appobjects that don't support
+            # any available interface
             implemented_interfaces = set()
             if 'Any' in self.get('etypes', ()):
                 for etype in self.schema.entities():
                     if etype.final:
                         continue
                     cls = self['etypes'].etype_class(etype)
+                    if cls.__implements__:
+                        warn('[3.9] %s: using __implements__/interfaces are '
+                             'deprecated in favor of adapters' % cls.__name__,
+                             DeprecationWarning)
                     for iface in cls.__implements__:
                         implemented_interfaces.update(iface.__mro__)
                     implemented_interfaces.update(cls.__mro__)
@@ -598,9 +614,17 @@
                     self.debug('kicking appobject %s (no implemented '
                                'interface among %s)', obj, ifaces)
                     self.unregister(obj)
-        # clear needs_iface so we don't try to remove some not-anymore-in
-        # objects on automatic reloading
-        self._needs_iface.clear()
+            # since 3.9: remove appobjects which depending on other, unexistant
+            # appobjects
+            for obj, (regname, regids) in self._needs_appobject.items():
+                registry = self[regname]
+                for regid in regids:
+                    if registry.get(regid):
+                        break
+                else:
+                    self.debug('kicking %s (no %s object in registry %s)',
+                               obj, ' or '.join(regids), registry)
+                    self.unregister(obj)
         super(CubicWebVRegistry, self).initialization_completed()
         for rtag in RTAGS:
             # don't check rtags if we don't want to cleanup_interface_sobjects