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 os
import subprocess
import wx
def get_inkscape_path():
""" Return the Inkscape path """
import _winreg
try:
svgexepath = _winreg.QueryValue(_winreg.HKEY_LOCAL_MACHINE,
'Software\\Classes\\svgfile\\shell\\Inkscape\\command')
except OSError:
svgexepath = _winreg.QueryValue(_winreg.HKEY_LOCAL_MACHINE,
'Software\\Classes\\inkscape.svg\\shell\\open\\command')
svgexepath = svgexepath.replace('"%1"', '')
return svgexepath.replace('"', '')
def open_win_svg(svgexepath, svgfile):
""" Open Inkscape on Windows platform """
popenargs = [svgexepath]
if svgfile is not None:
popenargs.append(svgfile)
subprocess.Popen(popenargs)
def open_lin_svg(svgexepath, svgfile):
""" Open Inkscape on Linux platform """
if os.path.isfile("/usr/bin/inkscape"):
os.system("%s %s &" % (svgexepath, svgfile))
def open_svg(svgfile):
""" Generic function to open SVG file """
if wx.Platform == '__WXMSW__':
try:
open_win_svg(get_inkscape_path(), svgfile)
except Exception:
wx.MessageBox("Inkscape is not found or installed !")
return None
else:
svgexepath = os.path.join("/usr/bin", "inkscape")
if os.path.isfile(svgexepath):
open_lin_svg(svgexepath, svgfile)
else:
wx.MessageBox("Inkscape is not found or installed !")
return None