beremiz

Dirty fix for error '_object_has_no_attribute_'getSlave' in EtherCAT extension

2018-08-10, Andrey Skvortsov
a3ac46366b86
Dirty fix for error '_object_has_no_attribute_'getSlave' in EtherCAT extension

traceback:
File "/home/developer/WorkData/PLC/beremiz/beremiz/IDEFrame.py", line 1433, in OnPouSelectedChanged
window.RefreshView()
File "/home/developer/WorkData/PLC/beremiz/beremiz/etherlab/ConfigEditor.py", line 837, in RefreshView
self.RefreshProcessVariables()
File "/home/developer/WorkData/PLC/beremiz/beremiz/etherlab/ConfigEditor.py", line 886, in RefreshProcessVariables
slaves = self.Controler.GetSlaves(**self.CurrentNodesFilter)
File "/home/developer/WorkData/PLC/beremiz/beremiz/etherlab/EthercatMaster.py", line 341, in GetSlaves
for slave in self.Config.getConfig().getSlave():
:_'lxml.etree._Element'_object_has_no_attribute_'getSlave'

Steps to reproduce problem:

- Add new EtherCAT master
- Add new EthercatNode to the master
- double click on


this is looks like dirty hack to fix strange problem with initial[0]
changing its type after returning from _init_ method to lxml.etree._Element
As a result all methods generated by class factory are lost.

For example, in function initMethod initial[0].__class__ points to
xmlclass.xmlclass.Config. After map(self.append, initial)
self.Config.__class__ is 'xmlclass.xmlclass.Config' as well.
But after returning from initMethod (_init) in CreateElement
self.Config.__class__ has changed to lxml.etree._Element.


I've noticed similar behavior if copy/deepcopy is used for any child
of etree.ElementBase. See simple example below.
[-------------------------------------------------------------]
#!/usr/bin/python

from __future__ import print_function
from lxml import etree
import copy

class DefaultElementClass(etree.ElementBase):
def getLocalTag(self):
return etree.QName(self.tag).localname


def printInformation(x):
print(x, x.__class__, "getLocalTag" in dir(x))


a = DefaultElementClass()
printInformation(a)

#
printInformation(copy.copy(a))
printInformation(copy.deepcopy(a))
[-------------------------------------------------------------]
#!/usr/bin/env python
# -*- coding: utf-8 -*-
# This file is part of Beremiz, a Integrated Development Environment for
# programming IEC 61131-3 automates supporting plcopen standard and CanFestival.
#
# Copyright (C) 2007: Edouard TISSERANT and Laurent BESSARD
#
# See COPYING file for copyrights details.
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version.
#
# This program 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 General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
from __future__ import absolute_import
import datetime
# -------------------------------------------------------------------------------
# Date and Time conversion function
# -------------------------------------------------------------------------------
SECOND = 1000000 # Number of microseconds in one second
MINUTE = 60 * SECOND # Number of microseconds in one minute
HOUR = 60 * MINUTE # Number of microseconds in one hour
DAY = 24 * HOUR # Number of microseconds in one day
# Date corresponding to Epoch (1970 January the first)
DATE_ORIGIN = datetime.datetime(1970, 1, 1)
def get_microseconds(value):
"""
Function converting time duration expressed in day, second and microseconds
into one expressed in microseconds
@param value: Time duration to convert
@return: Time duration expressed in microsecond
"""
return float(value.days * DAY +
value.seconds * SECOND +
value.microseconds)
def generate_time(value):
"""
Function converting time duration expressed in day, second and microseconds
into a IEC 61131 TIME literal
@param value: Time duration to convert
@return: IEC 61131 TIME literal
"""
microseconds = get_microseconds(value)
# Get absolute microseconds value and save if it was negative
negative = microseconds < 0
microseconds = abs(microseconds)
# TIME literal prefix
data = "T#"
if negative:
data += "-"
# In TIME literal format, it isn't mandatory to indicate null values
# if no greater non-null values are available. This variable is used to
# inhibit formatting until a non-null value is found
not_null = False
for val, format in [
(int(microseconds) / DAY, "%dd"), # Days
((int(microseconds) % DAY) / HOUR, "%dh"), # Hours
((int(microseconds) % HOUR) / MINUTE, "%dm"), # Minutes
((int(microseconds) % MINUTE) / SECOND, "%ds")]: # Seconds
# Add value to TIME literal if value is non-null or another non-null
# value have already be found
if val > 0 or not_null:
data += format % val
# Update non-null variable
not_null = True
# In any case microseconds have to be added to TIME literal
data += "%gms" % (microseconds % SECOND / 1000.)
return data
def generate_date(value):
"""
Function converting time duration expressed in day, second and microseconds
into a IEC 61131 DATE literal
@param value: Time duration to convert
@return: IEC 61131 DATE literal
"""
return (DATE_ORIGIN + value).strftime("DATE#%Y-%m-%d")
def generate_datetime(value):
"""
Function converting time duration expressed in day, second and microseconds
into a IEC 61131 DATE_AND_TIME literal
@param value: Time duration to convert
@return: IEC 61131 DATE_AND_TIME literal
"""
return (DATE_ORIGIN + value).strftime("DT#%Y-%m-%d-%H:%M:%S.%f")
def generate_timeofday(value):
"""
Function converting time duration expressed in day, second and microseconds
into a IEC 61131 TIME_OF_DAY literal
@param value: Time duration to convert
@return: IEC 61131 TIME_OF_DAY literal
"""
microseconds = get_microseconds(value)
# TIME_OF_DAY literal prefix
data = "TOD#"
for val, format in [
(int(microseconds) / HOUR, "%2.2d:"), # Hours
((int(microseconds) % HOUR) / MINUTE, "%2.2d:"), # Minutes
((int(microseconds) % MINUTE) / SECOND, "%2.2d."), # Seconds
(microseconds % SECOND, "%6.6d")]: # Microseconds
# Add value to TIME_OF_DAY literal
data += format % val
return data
# Dictionary of translation functions from value send by debugger to IEC
# literal stored by type
TYPE_TRANSLATOR = {
"TIME": generate_time,
"DATE": generate_date,
"DT": generate_datetime,
"TOD": generate_timeofday,
"STRING": lambda v: "'%s'" % v,
"WSTRING": lambda v: '"%s"' % v,
"REAL": lambda v: "%.6g" % v,
"LREAL": lambda v: "%.6g" % v}
# -------------------------------------------------------------------------------
# Debug Data Consumer Class
# -------------------------------------------------------------------------------
class DebugDataConsumer(object):
"""
Class that implements an element that consumes debug values
Value update can be inhibited during the time the associated Debug Viewer is
refreshing
"""
def __init__(self):
"""
Constructor
"""
# Debug value and forced flag
self.Value = None
self.Forced = False
# Store debug value and forced flag when value update is inhibited
self.LastValue = None
self.LastForced = False
# Value IEC data type
self.DataType = None
# Flag that value update is inhibited
self.Inhibited = False
def Inhibit(self, inhibit):
"""
Set flag to inhibit or activate value update
@param inhibit: Inhibit flag
"""
# Save inhibit flag
self.Inhibited = inhibit
# When reactivated update value and forced flag with stored values
if not inhibit and self.LastValue is not None:
self.SetForced(self.LastForced)
self.SetValue(self.LastValue)
# Reset stored values
self.LastValue = None
self.LastForced = False
def SetDataType(self, data_type):
"""
Set value IEC data type
@param data_type: Value IEC data type
"""
self.DataType = data_type
def NewValues(self, tick, values, raw="BOOL"):
"""
Function called by debug thread when a new debug value is available
@param tick: PLC tick when value was captured
@param value: Value captured
@param forced: Forced flag, True if value is forced (default: False)
@param raw: Data type of values not translated (default: 'BOOL')
"""
value, forced = values
# Translate value to IEC literal
if self.DataType != raw:
value = TYPE_TRANSLATOR.get(self.DataType, str)(value)
# Store value and forced flag when value update is inhibited
if self.Inhibited:
self.LastValue = value
self.LastForced = forced
# Update value and forced flag in any other case
else:
self.SetForced(forced)
self.SetValue(value)
def SetValue(self, value):
"""
Update value.
May be overridden by inherited classes
@param value: New value
"""
self.Value = value
def GetValue(self):
"""
Return current value
@return: Current value
"""
return self.Value
def SetForced(self, forced):
"""
Update Forced flag.
May be overridden by inherited classes
@param forced: New forced flag
"""
self.Forced = forced
def IsForced(self):
"""
Indicate if current value is forced
@return: Current forced flag
"""
return self.Forced