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

<?xml version="1.0" encoding="UTF-8" standalone="no"?>

     2

<PyFile>

     3

  <variables/>

     4

  <globals>

     5

<![CDATA[

     6

from threading import Thread

     7

     8

def OnConnectButton(self, event):

     9

  def OnWiiConnected(mac_addr):

    10

    self.label_2.SetLabel(

    11

      "Wiimote %s connected"%mac_addr 

    12

      if mac_addr else 

    13

      "Wiimote connection failed !")

    14

    15

  def WiiConnected(mac_addr):

    16

    wx.CallAfter(OnWiiConnected,mac_addr)

    17

    18

  Thread(target = Connect_Wiimote, args = (WiiConnected,)).start()

    19

  self.label_2.SetLabel("Press wiimote 1+2")

    20

  event.Skip()

    21

    22

def OnDisconnectButton(self, event):

    23

  Disconnect_Wiimote()

    24

  self.label_2.SetLabel("Wiimote disconnected")

    25

  event.Skip()

    26

    27

]]>

    28

  </globals>

    29

  <init>

    30

<![CDATA[

    31

]]>

    32

  </init>

    33

  <cleanup>

    34

<![CDATA[

    35

]]>

    36

  </cleanup>

    37

  <start>

    38

<![CDATA[

    39

]]>

    40

  </start>

    41

  <stop>

    42

<![CDATA[

    43

]]>

    44

  </stop>

    45

</PyFile>