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))
[-------------------------------------------------------------]

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/*

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Template C code used to produce target Ethercat C code.

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Copyright (C) 2011-2014: Laurent BESSARD, Edouard TISSERANT

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Distributed under the terms of the GNU Lesser General Public License as

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published by the Free Software Foundation; either version 2 of the License, or

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(at your option) any later version.

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See COPYING file for copyrights details.

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*/

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#include "iec_types_all.h"

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#define FREE 0

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#define ACQUIRED 1

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#define ANSWERED 2

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long SDOLock = FREE;

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extern long AtomicCompareExchange(long* atomicvar,long compared, long exchange);

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int AcquireSDOLock() {

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	return AtomicCompareExchange(&SDOLock, FREE, ACQUIRED) == FREE;

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}

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void SDOAnswered() {

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	AtomicCompareExchange(&SDOLock, ACQUIRED, ANSWERED);

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}

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int HasAnswer() {

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	return SDOLock == ANSWERED;

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}

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void ReleaseSDOLock() {

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	AtomicCompareExchange(&SDOLock, ANSWERED, FREE);

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}

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int __init_etherlab_ext()

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{

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    SDOLock = FREE;

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    return 0;

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}

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void __cleanup_etherlab_ext()

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{

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}

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void __retrieve_etherlab_ext()

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{

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}

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void __publish_etherlab_ext()

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{

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}