beremiz

Proper fix for error 'object has no attribute 'getSlave' in EtherCAT extension

2018-08-24, Andrey Skvortsov
96ca6b056c55
Proper 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


Revert commit "Dirty fix for error '_object_has_no_attribute_'getSlave' in EtherCAT extension"
[a3ac46366b86a0b237dac93be6b2281ac70b98a8].

The problem was that XML elements (proxy object) in some cases were created using custom XML
classes constructors and lxml.etree.Element() call and live python
patching. This causes that lxml backend doesn't know that custom python class
should be used for these XML elements.
Proxy object can be move/deleted and recreated by lxml
backend at any point in time or this can be done in python by copy/deepcopy operations.
If this happens, then newly created
proxy elements are using default class lxml.etree._Element. And all
custom functionality is lost.

All created XML elements should be always created through corresponding
parser and class lookup callback done by lxml backend.
It's described in more details in lxml documentation:
https://lxml.de/element_classes.html
#!/usr/bin/env python
# -*- coding: utf-8 -*-
# This file is part of Beremiz, a Integrated Development Environment for
# programming IEC 61131-3 automates supporting plcopen standard and CanFestival.
#
# Copyright (C) 2007: Edouard TISSERANT and Laurent BESSARD
#
# See COPYING file for copyrights details.
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
from __future__ import absolute_import
import os
from c_ext.CFileEditor import CFileEditor
from CodeFileTreeNode import CodeFile
class CFile(CodeFile):
XSD = """<?xml version="1.0" encoding="ISO-8859-1" ?>
<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema">
<xsd:element name="CExtension">
<xsd:complexType>
<xsd:attribute name="CFLAGS" type="xsd:string" use="required"/>
<xsd:attribute name="LDFLAGS" type="xsd:string" use="required"/>
</xsd:complexType>
</xsd:element>
</xsd:schema>
"""
CODEFILE_NAME = "CFile"
SECTIONS_NAMES = [
"includes",
"globals",
"initFunction",
"cleanUpFunction",
"retrieveFunction",
"publishFunction"]
EditorType = CFileEditor
def GetIconName(self):
return "Cfile"
def CodeFileName(self):
return os.path.join(self.CTNPath(), "cfile.xml")
def CTNGenerate_C(self, buildpath, locations):
"""
Generate C code
@param current_location: Tupple containing confnode IEC location : %I0.0.4.5 => (0,0,4,5)
@param locations: List of complete variables locations \
[{"IEC_TYPE" : the IEC type (i.e. "INT", "STRING", ...)
"NAME" : name of the variable (generally "__IW0_1_2" style)
"DIR" : direction "Q","I" or "M"
"SIZE" : size "X", "B", "W", "D", "L"
"LOC" : tuple of interger for IEC location (0,1,2,...)
}, ...]
@return: [(C_file_name, CFLAGS),...] , LDFLAGS_TO_APPEND
"""
current_location = self.GetCurrentLocation()
# define a unique name for the generated C file
location_str = "_".join(map(str, current_location))
text = "/* Code generated by Beremiz c_ext confnode */\n\n"
text += "#include <stdio.h>\n\n"
# Adding includes
text += "/* User includes */\n"
text += self.CodeFile.includes.getanyText().strip()
text += "\n"
text += '#include "iec_types_all.h"\n\n'
# Adding variables
config = self.GetCTRoot().GetProjectConfigNames()[0]
text += "/* User variables reference */\n"
for variable in self.CodeFile.variables.variable:
var_infos = {
"name": variable.getname(),
"global": "%s__%s" % (config.upper(),
variable.getname().upper()),
"type": "__IEC_%s_t" % variable.gettype()}
text += "extern %(type)s %(global)s;\n" % var_infos
text += "#define %(name)s %(global)s.value\n" % var_infos
text += "\n"
# Adding user global variables and routines
text += "/* User internal user variables and routines */\n"
text += self.CodeFile.globals.getanyText().strip()
text += "\n"
# Adding Beremiz confnode functions
text += "/* Beremiz confnode functions */\n"
text += "int __init_%s(int argc,char **argv)\n{\n" % location_str
text += self.CodeFile.initFunction.getanyText().strip()
text += " return 0;\n}\n\n"
text += "void __cleanup_%s(void)\n{\n" % location_str
text += self.CodeFile.cleanUpFunction.getanyText().strip()
text += "\n}\n\n"
text += "void __retrieve_%s(void)\n{\n" % location_str
text += self.CodeFile.retrieveFunction.getanyText().strip()
text += "\n}\n\n"
text += "void __publish_%s(void)\n{\n" % location_str
text += self.CodeFile.publishFunction.getanyText().strip()
text += "\n}\n\n"
Gen_Cfile_path = os.path.join(buildpath, "CFile_%s.c" % location_str)
cfile = open(Gen_Cfile_path, 'w')
cfile.write(text)
cfile.close()
matiec_CFLAGS = '"-I%s"' % os.path.abspath(self.GetCTRoot().GetIECLibPath())
return [(Gen_Cfile_path, str(self.CExtension.getCFLAGS() + matiec_CFLAGS))], str(self.CExtension.getLDFLAGS()), True