#!/usr/bin/env python
#############################################################################
##
# This file is part of Taurus
##
# http://taurus-scada.org
##
# Copyright 2011 CELLS / ALBA Synchrotron, Bellaterra, Spain
##
# Taurus is free software: you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
##
# Taurus is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU Lesser General Public License for more details.
##
# You should have received a copy of the GNU Lesser General Public License
# along with Taurus. If not, see <http://www.gnu.org/licenses/>.
##
#############################################################################
"""This module contains the base TaurusModel class"""
from builtins import object
import weakref
try:
from collections.abc import Sequence
except ImportError: # bck-compat py 2.7
from collections import Sequence
from .util.log import Logger
from .util.event import (CallableRef,
BoundMethodWeakref,
_BoundMethodWeakrefWithCall)
from .taurusbasetypes import TaurusEventType, MatchLevel
from .taurushelper import Factory
__all__ = ["TaurusModel"]
__docformat__ = "restructuredtext"
[docs]class TaurusModel(Logger):
_factory = None
RegularEvent = (TaurusEventType.Change,
TaurusEventType.Config, TaurusEventType.Periodic)
def __init__(self, full_name='', parent=None, serializationMode=None):
v = self.getNameValidator()
self._full_name, self._norm_name, self._simp_name = v.getNames(
full_name, self.factory())
if self._full_name is None and self._norm_name and self._simp_name is None:
self.trace("invalid name")
name = self._simp_name or self._norm_name or self._full_name or 'TaurusModel'
self.call__init__(Logger, name, parent)
if serializationMode is None:
s_obj = parent
if s_obj is None:
s_obj = self.factory()
serializationMode = s_obj.getSerializationMode()
self._serialization_mode = serializationMode
self._parentObj = parent
self._listeners = []
def __str__name__(self, name):
return '{0}({1})'.format(self.__class__.__name__, name)
def __str__(self):
return self.__str__name__(self.getNormalName())
def __repr__(self):
return self.__str__name__(self.getFullName())
[docs] def cleanUp(self):
self.trace("[TaurusModel] cleanUp")
self._parentObj = None
self._listeners = None
Logger.cleanUp(self)
#-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-
# API for Factory access
#-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-
[docs] @classmethod
def factory(cls):
if cls._factory is None:
cls._factory = Factory(scheme=cls._scheme)
return cls._factory
#-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-
# API for naming
#-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-
[docs] @classmethod
def getTaurusElementType(cls):
raise NotImplementedError("TaurusModel.getTaurusElementType cannot"
" be called")
[docs] def getFullName(self):
return self._full_name
[docs] def getNormalName(self):
return self._norm_name
[docs] def getSimpleName(self):
return self._simp_name
[docs] @classmethod
def isValid(cls, *args, **kwargs):
return cls.getNameValidator().isValid(*args, **kwargs)
[docs] @classmethod
def buildModelName(cls, parent_model, relative_name):
raise NotImplementedError(
"TaurusModel.buildModelName cannot be called")
[docs] @classmethod
def getNameValidator(cls):
raise NotImplementedError("TaurusModel.getNameValidator cannot be"
"called")
#-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-
# API for hierarchy access
#-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-
[docs] def getParentObj(self):
return self._parentObj
[docs] def getChildObj(self, child_name):
return None # TODO: consider raising NotImplementedError instead
#-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-
# API for serialization
#-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-
[docs] def setSerializationMode(self, mode):
"""Sets the serialization mode for the system.
:param mode: (TaurusSerializationMode) the new serialization mode"""
self._serialization_mode = mode
[docs] def getSerializationMode(self):
"""Gives the serialization operation mode.
:return: (TaurusSerializationMode) the current serialization mode"""
return self._serialization_mode
#-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-
# API for value access
#-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-
[docs] def getDisplayDescrObj(self, cache=True):
"""A brief description of the model. Can be used as tooltip, for example"""
raise NotImplementedError("TaurusModel.getDisplayDescrObj cannot be"
" called")
[docs] def getDisplayName(self, cache=True, complete=True):
full_name = self.getFullName()
normal_name = self.getNormalName()
simple_name = self.getSimpleName()
if simple_name:
ret = simple_name
if complete:
ret += " (" + normal_name.upper() + ")"
elif normal_name:
ret = normal_name.upper()
else:
ret = full_name.upper()
return ret
[docs] def getFragmentObj(self, fragmentName=None):
"""Returns a fragment object of the model. A fragment is computed from
a model by evaluating the expression `<model>.<fragmentName>`
For a simple fragmentName (no dots), this is roughly equivalent to
getattr(self, fragmentName)
If the fragment cannot be computed, :class:`AttributeError` is raised
:param fragmentName: (str or None) the returned value will correspond to
the given fragmentName. If None is passed the
defaultFragmentName will be used instead.
:return: (obj) the computed fragment of the modelObj.
"""
if fragmentName is None:
fragmentName = self.defaultFragmentName
try:
return eval('obj.' + fragmentName, {}, {'obj' : self})
except Exception as e:
# Note: always raise AttributeError to comply with existing API
msg = "Cannot get fragment of {!r}.{!s}: Reason: {!r}"
raise AttributeError(msg.format(self, fragmentName, e))
#-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-
# API for listeners
#-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-
def _listenerDied(self, weak_listener):
if self._listeners is None:
return
try:
self._listeners.remove(weak_listener)
except Exception as e:
self.debug("Problem removing listener: %r", e)
def _getCallableRef(self, listener, cb=None):
# return weakref.ref(listener, self._listenerDied)
meth = getattr(listener, 'eventReceived', None)
if meth is not None and hasattr(meth, '__call__'):
return weakref.ref(listener, cb)
else:
return CallableRef(listener, cb)
[docs] def addListener(self, listener):
if self._listeners is None or listener is None:
return False
# TODO: _BoundMethodWeakrefWithCall is used as workaround for
# PyTango #185 issue
weak_listener = self._getCallableRef(
listener, _BoundMethodWeakrefWithCall(self._listenerDied))
# listener, self._listenerDied)
if weak_listener in self._listeners:
return False
self._listeners.append(weak_listener)
return True
[docs] def removeListener(self, listener):
if self._listeners is None:
return
weak_listener = self._getCallableRef(listener)
try:
self._listeners.remove(weak_listener)
except Exception as e:
return False
return True
[docs] def forceListening(self):
class __DummyListener(object):
def eventReceived(self, *args):
pass
if not hasattr(self, '__dummyListener') or self.__dummyListener is None:
self.__dummyListener = __DummyListener()
self.addListener(self.__dummyListener)
[docs] def unforceListening(self):
if hasattr(self, '__dummyListener') and self.__dummyListener is not None:
self.removeListener(self.__dummyListener)
self.__dummyListener = None
[docs] def deleteListener(self, listener):
self.deprecated("Use removeListener(listener) instead")
self.removeListener(listener)
[docs] def hasListeners(self):
""" returns True if anybody is listening to events from this attribute """
if self._listeners is None:
return False
return len(self._listeners) > 0
[docs] def fireEvent(self, event_type, event_value, listeners=None):
"""sends an event to all listeners or a specific one"""
if listeners is None:
listeners = self._listeners
if listeners is None:
return
if not isinstance(listeners, Sequence):
listeners = listeners,
for listener in listeners:
if isinstance(listener, weakref.ref) or isinstance(listener, BoundMethodWeakref):
l = listener()
else:
l = listener
if l is None:
continue
meth = getattr(l, 'eventReceived', None)
if meth is not None and hasattr(meth, '__call__'):
l.eventReceived(self, event_type, event_value)
elif hasattr(l, '__call__'):
l(self, event_type, event_value)
[docs] def isWritable(self):
return False
@property
def name(self):
return self._simp_name
@property
def fullname(self):
return self._full_name
parentObj = property(fget=getParentObj)