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

/**
 * Head of code common to all C targets
 **/

#include "beremiz.h"
#include <string.h>
/*
 * Prototypes of functions provided by generated C softPLC
 **/
void config_run__(unsigned long tick);
void config_init__(void);

/*
 * Prototypes of functions provided by generated target C code
 * */
long long AtomicCompareExchange64(long long*, long long, long long);
void __init_debug(void);
void __cleanup_debug(void);
/*void __retrieve_debug(void);*/
void __publish_debug(void);

/*
 *  Variables used by generated C softPLC and plugins
 **/
IEC_TIME __CURRENT_TIME;
IEC_BOOL __DEBUG = 0;
unsigned long __tick = 0;
char *PLC_ID = NULL;

/*
 *  Variable generated by C softPLC and plugins
 **/
extern unsigned long greatest_tick_count__;

/* Help to quit cleanly when init fail at a certain level */
static int init_level = 0;

/* Prototype for Logging to help spotting errors at init */
int LogMessage(uint8_t level, char* buf, uint32_t size);

/*
 * Prototypes of functions exported by plugins
 **/
%(calls_prototypes)s

/*
 * Retrieve input variables, run PLC and publish output variables
 **/
void __run(void)
{
    __tick++;
    if (greatest_tick_count__)
        __tick %%= greatest_tick_count__;

    %(retrieve_calls)s

    /*__retrieve_debug();*/

    config_run__(__tick);

    __publish_debug();

    %(publish_calls)s

}

/*
 * Initialize variables according to PLC's default values,
 * and then init plugins with that values
 **/
int __init(int argc,char **argv)
{
    int res = 0;
    init_level = 0;
    
    /* Effective tick time with 1ms default value */
    if(!common_ticktime__)
        common_ticktime__ = 1000000;

    config_init__();
    __init_debug();
    %(init_calls)s
    return res;
}
/*
 * Calls plugin cleanup proc.
 **/
void __cleanup(void)
{
    %(cleanup_calls)s
    __cleanup_debug();
}

void PLC_GetTime(IEC_TIME *CURRENT_TIME);
void PLC_SetTimer(unsigned long long next, unsigned long long period);