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
# Copyright (C) 2017: Andrey Skvortsov
#
# 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 os
from POULibrary import POULibrary
from py_ext.PythonFileCTNMixin import PythonFileCTNMixin
import util.paths as paths
class PythonLibrary(POULibrary):
def GetLibraryPath(self):
return paths.AbsNeighbourFile(__file__, "pous.xml")
def Generate_C(self, buildpath, varlist, IECCFLAGS):
plc_python_filepath = paths.AbsNeighbourFile(__file__, "plc_python.c")
plc_python_file = open(plc_python_filepath, 'r')
plc_python_code = plc_python_file.read()
plc_python_file.close()
python_eval_fb_list = []
for v in varlist:
if v["vartype"] == "FB" and v["type"] in ["PYTHON_EVAL",
"PYTHON_POLL"]:
python_eval_fb_list.append(v)
python_eval_fb_count = max(1, len(python_eval_fb_list))
# prepare python code
plc_python_code = plc_python_code % {
"python_eval_fb_count": python_eval_fb_count}
Gen_Pythonfile_path = os.path.join(buildpath, "py_ext.c")
pythonfile = open(Gen_Pythonfile_path, 'w')
pythonfile.write(plc_python_code)
pythonfile.close()
return (["py_ext"], [(Gen_Pythonfile_path, IECCFLAGS)], True), ""
class PythonFile(PythonFileCTNMixin):
def GetIconName(self):
return "Pyfile"