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

// import Nevow.Athena

     2

// import Divmod.Base

     3

     4

function updateAttr(id, param, value) {

     5

  Nevow.Athena.Widget.fromAthenaID(1).callRemote('HMIexec', 'setattr', id, param, value);

     6

}

     7

     8

var svguiWidgets = new Array();

     9

    10

var currentObject = null;

    11

function setCurrentObject(obj) {

    12

	currentObject = obj;

    13

}

    14

function isCurrentObject(obj) {

    15

	return currentObject == obj;

    16

}

    17

    18

function getSVGElementById(id) {

    19

	return document.getElementById(id);

    20

}

    21

    22

function blockSVGElementDrag(element) {

    23

	element.addEventListener("draggesture", function(event){event.stopPropagation()}, true);

    24

}

    25

    26

LiveSVGPage.LiveSVGWidget = Nevow.Athena.Widget.subclass('LiveSVGPage.LiveSVGWidget');

    27

LiveSVGPage.LiveSVGWidget.methods(

    28

    29

    function handleEvent(self, evt) {

    30

        if (currentObject != null) {

    31

            currentObject.handleEvent(evt);

    32

        }

    33

    },

    34

    35

    function receiveData(self, data){

    36

        dataReceived = json_parse(data);

    37

        gadget = svguiWidgets[dataReceived.id]

    38

        if (gadget) {

    39

        	gadget.updateValues(json_parse(dataReceived.kwargs));

    40

        }

    41

        //console.log("OBJET : " + dataReceived.back_id + " STATE : " + newState);

    42

    },

    43

    44

    function init(self, arg1){

    45

        //console.log("Object received : " + arg1);

    46

        for (ind in arg1) {

    47

            gad = json_parse(arg1[ind]);

    48

            args = json_parse(gad.kwargs);

    49

            gadget = new svguilib[gad.__class__](self, gad.id, args);

    50

            svguiWidgets[gadget.id]=gadget;

    51

            //console.log('GADGET :' + gadget);

    52

        }

    53

        var elements = document.getElementsByTagName("svg");

    54

        for (var i = 0; i < elements.length; i++) {

    55

        	elements[i].addEventListener("mouseup", self, false);

    56

        }

    57

        //console.log("SVGUIWIDGETS : " + svguiWidgets);

    58

    }

    59

);