fix missing update after error on parameter

the main error was a suppressed update when the value does not
change, but the readerror gets None

this error was the reason for strange behaviour in frappy.proxy
while finding the cause, other improvements were done:

- nodeStateChange: add 'activating' to the possible online states
- improve status handling in proxy

Change-Id: I2a1873065ab051bdba2200f50e6ad09ae55e168e
Reviewed-on: https://forge.frm2.tum.de/review/c/secop/frappy/+/33901
Tested-by: Jenkins Automated Tests <pedersen+jenkins@frm2.tum.de>
Reviewed-by: Enrico Faulhaber <enrico.faulhaber@frm2.tum.de>
Reviewed-by: Markus Zolliker <markus.zolliker@psi.ch>

frappy/client/__init__.py

@@ -370,9 +370,10 @@ class SecopClient(ProxyClient):
                     # pylint: disable=unsubscriptable-object
                     self._init_descriptive_data(self.request(DESCRIPTIONREQUEST)[2])
                     self.nodename = self.properties.get('equipment_id', self.uri)
-                    self._set_state(True, 'connected')
                     if self.activate:
+                        self._set_state(True, 'activating')
                         self.request(ENABLEEVENTSREQUEST)
+                    self._set_state(True, 'connected')
                     break
                 except Exception:
                     # print(formatExtendedTraceback())

frappy/modulebase.py

@@ -524,7 +524,7 @@ class Module(HasAccessibles):
                 except Exception as e:
                     err = e
                 else:
-                    changed = pobj.value != value
+                    changed = pobj.value != value or pobj.readerror
                     # store the value even in case of error
                     pobj.value = value
             if err:

frappy/proxy.py

@@ -30,11 +30,15 @@ from frappy.properties import Property
 from frappy.io import HasIO
 
 
+DISCONNECTED = Readable.Status.ERROR, 'disconnected'
+
+
 class ProxyModule(HasIO, Module):
     module = Property('remote module name', datatype=StringType(), default='')
     status = Parameter('connection status', Readable.status.datatype)  # add status even when not a Readable
 
     _consistency_check_done = False
+    _connection_status = None  # status when not connected
     _secnode = None
     enablePoll = False
 
@@ -45,6 +49,8 @@ class ProxyModule(HasIO, Module):
     def updateEvent(self, module, parameter, value, timestamp, readerror):
         if parameter not in self.parameters:
             return  # ignore unknown parameters
+        if parameter == 'status' and not readerror:
+            self._connection_status = None
         # should be done here: deal with clock differences
         self.announceUpdate(parameter, value, readerror, timestamp)
 
@@ -108,19 +114,18 @@ class ProxyModule(HasIO, Module):
         # for now, the error message must be enough
 
     def nodeStateChange(self, online, state):
-        disconnected = Readable.Status.ERROR, 'disconnected'
         if online:
             if not self._consistency_check_done:
                 self._check_descriptive_data()
                 self._consistency_check_done = True
-            if self.status == disconnected:
+            if self._connection_status:
-                self.status = Readable.Status.IDLE, 'connected'
+                self.status = Readable.Status.IDLE, state
         else:
             readerror = CommunicationFailedError('disconnected')
             if self.status != disconnected:
                 for pname in set(self.parameters) - set(('module', 'status')):
                     self.announceUpdate(pname, None, readerror)
-                self.status = disconnected
+                self.status = self._connection_status = DISCONNECTED
 
     def checkProperties(self):
         pass  # skip