fix inheritance problem with mixin

- a mixin should not inherit from module then it has Parameters
- Parameters in mixins must be complete, not just overrides
- check precedence of read_<param> or handler

Change-Id: I72d9355a1982770d1a99d9552a20330103c97edb

secop/client/__init__.py

@@ -495,9 +495,12 @@ class SecopClient(ProxyClient):
     def _set_state(self, online, state=None):
         # treat reconnecting as online!
         state = state or self.state
-        self.callback(None, 'nodeStateChange', online, state)
-        for mname in self.modules:
-            self.callback(mname, 'nodeStateChange', online, state)
+        try:
+            self.callback(None, 'nodeStateChange', online, state)
+            for mname in self.modules:
+                self.callback(mname, 'nodeStateChange', online, state)
+        except Exception as e:
+            self.log.error('ERROR in nodeStateCallback %s', e)
         # set online attribute after callbacks -> callback may check for old state
         self.online = online
         self.state = state

secop/lib/__init__.py

@@ -98,14 +98,17 @@ def clamp(_min, value, _max):
 
 
 def get_class(spec):
-    """loads a class given by string in dotted notaion (as python would do)"""
+    """loads a class given by string in dotted notation (as python would do)"""
     modname, classname = spec.rsplit('.', 1)
     if modname.startswith('secop'):
         module = importlib.import_module(modname)
     else:
         # rarely needed by now....
         module = importlib.import_module('secop.' + modname)
-    return getattr(module, classname)
+    try:
+        return getattr(module, classname)
+    except AttributeError:
+        raise AttributeError('no such class') from None
 
 
 def mkthread(func, *args, **kwds):

secop/modules.py

@@ -93,10 +93,13 @@ class HasAccessibles(HasProperties):
             rfunc_handler = pobj.handler.get_read_func(cls, pname) if pobj.handler else None
             wrapped = hasattr(rfunc, '__wrapped__')
             if rfunc_handler:
-                if rfunc and not wrapped:
-                    raise ProgrammingError("parameter '%s' can not have a handler "
-                                           "and read_%s" % (pname, pname))
-                rfunc = rfunc_handler
+                if 'read_' + pname in cls.__dict__:
+                    if pname in cls.__dict__:
+                        raise ProgrammingError("parameter '%s' can not have a handler "
+                                               "and read_%s" % (pname, pname))
+                    # read_<pname> overwrites inherited handler
+                else:
+                    rfunc = rfunc_handler
                 wrapped = False
 
             # create wrapper except when read function is already wrapped

secop/params.py

@@ -101,10 +101,10 @@ class Parameter(Accessible):
 
     description = Property(
         'mandatory description of the parameter', TextType(),
-        extname='description', mandatory=True)
+        extname='description', mandatory=True, export='always')
     datatype = Property(
         'datatype of the Parameter (SECoP datainfo)', DataTypeType(),
-        extname='datainfo', mandatory=True)
+        extname='datainfo', mandatory=True, export='always')
     readonly = Property(
         'not changeable via SECoP (default True)', BoolType(),
         extname='readonly', default=True, export='always')
@@ -283,7 +283,7 @@ class Command(Accessible):
 
     description = Property(
         'description of the Command', TextType(),
-        extname='description', export=True, mandatory=True)
+        extname='description', export='always', mandatory=True)
     group = Property(
         'optional command group of the command.', StringType(),
         extname='group', export=True, default='')

secop/server.py

@@ -228,11 +228,15 @@ class Server:
             errors.append(self.unknown_options(cls, opts))
         self.modules = OrderedDict()
         badclass = None
+        failed = set()  # python modules failed to load
         self.lastError = None
         for modname, options in self.module_cfg.items():
             opts = dict(options)
             try:
                 classname = opts.pop('class')
+                pymodule = classname.rpartition('.')[0]
+                if pymodule in failed:
+                    continue
                 cls = get_class(classname)
                 modobj = cls(modname, self.log.getChild(modname), opts, self)
                 # all used args should be popped from opts!
@@ -242,8 +246,12 @@ class Server:
             except ConfigError as e:
                 errors.append(str(e))
             except Exception as e:
-                badclass = classname
-                errors.append('error while loading %s' % badclass)
+                if str(e) == 'no such class':
+                    errors.append('%s not found' % classname)
+                else:
+                    failed.add(pymodule)
+                    badclass = classname
+                    errors.append('error importing %s' % pymodule)
 
         poll_table = dict()
         # all objs created, now start them up and interconnect