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():
<type 'exceptions.AttributeError'>:_'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))
[-------------------------------------------------------------]

     1

#!/usr/bin/env python

     2

# -*- coding: utf-8 -*-

     3

     4

# This file is part of Beremiz, a Integrated Development Environment for

     5

# programming IEC 61131-3 automates supporting plcopen standard and CanFestival.

     6

#

     7

# Copyright (C) 2007: Edouard TISSERANT and Laurent BESSARD

     8

# Copyright (C) 2017: Andrey Skvortsov

     9

#

    10

# See COPYING file for copyrights details.

    11

#

    12

# This program is free software; you can redistribute it and/or

    13

# modify it under the terms of the GNU General Public License

    14

# as published by the Free Software Foundation; either version 2

    15

# of the License, or (at your option) any later version.

    16

#

    17

# This program is distributed in the hope that it will be useful,

    18

# but WITHOUT ANY WARRANTY; without even the implied warranty of

    19

# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

    20

# GNU General Public License for more details.

    21

#

    22

# You should have received a copy of the GNU General Public License

    23

# along with this program; if not, write to the Free Software

    24

# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.

    25

    26

    27

from __future__ import absolute_import

    28

import util.paths as paths

    29

from POULibrary import SimplePOULibraryFactory

    30

    31

NativeLibrary = SimplePOULibraryFactory(

    32

    paths.AbsNeighbourFile(__file__, "NativeLib.xml"))