#!/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/>.
#
# ###########################################################################
from taurus.core.taurusdevice import TaurusDevice
from taurus.core.util.safeeval import SafeEvaluator
from taurus.core.taurusbasetypes import TaurusDevState, TaurusAttrValue
[docs]
class EvaluationDevice(TaurusDevice, SafeEvaluator):
"""The evaluator object. It is a :class:`TaurusDevice` and is used as the
parent of :class:`EvaluationAttribute` objects for which it performs the
mathematical evaluation.
.. seealso:: :mod:`taurus.core.evaluation`
.. warning:: In most cases this class should not be instantiated directly.
Instead it should be done via the
:meth:`EvaluationFactory.getDevice`
"""
_symbols = []
# helper class property that stores a reference to the corresponding
# factory
_factory = None
_scheme = "eval"
def __init__(self, name="", **kw):
"""Object initialization."""
self.call__init__(TaurusDevice, name, **kw)
safedict = {}
for s in self._symbols:
if hasattr(self, s):
safedict[s] = getattr(self, s)
SafeEvaluator.__init__(self, safedict=safedict)
# -~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~
# TaurusDevice necessary overwrite
# -~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~
def _createHWObject(self):
return "Evaluation"
# -~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~
[docs]
def getAttribute(self, attrname):
"""Returns the attribute object given its name"""
full_attrname = "%s;%s" % (self.getFullName(), attrname)
return self.factory().getAttribute(full_attrname)
[docs]
def decode(self, event_value):
# TODO: Is this method ever called? (or maybe just garbage from 3.x?)
if isinstance(event_value, int): # TaurusSWDevState
new_sw_state = event_value
else:
self.info("Unexpected value to decode: %s" % str(event_value))
new_sw_state = TaurusDevState.NotReady
value = TaurusAttrValue()
value.rvalue = new_sw_state
return value