beremiz

Dirty fix for error '_object_has_no_attribute_'getSlave' in EtherCAT extension

2018-08-10, Andrey Skvortsov
a3ac46366b86
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():
:_'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);