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))
[-------------------------------------------------------------]
#!/usr/bin/env python
# -*- coding: utf-8 -*-
# This file is part of Beremiz.
# See COPYING file for copyrights details.
from __future__ import absolute_import
from plcopen.XSLTModelQuery import XSLTModelQuery, _StringValue, _BoolValue, _translate_args
from plcopen.types_enums import CLASS_TYPES, POU_TYPES, VAR_CLASS_INFOS
def class_extraction(value):
class_type = CLASS_TYPES.get(value)
if class_type is not None:
return class_type
pou_type = POU_TYPES.get(value)
if pou_type is not None:
return pou_type
var_type = VAR_CLASS_INFOS.get(value)
if var_type is not None:
return var_type[1]
return None
class _VariablesTreeItemInfos(object):
__slots__ = ["name", "var_class", "type", "edit", "debug", "variables"]
def __init__(self, *args):
for attr, value in zip(self.__slots__, args):
setattr(self, attr, value if value is not None else "")
def copy(self):
return _VariablesTreeItemInfos(*[getattr(self, attr) for attr in self.__slots__])
class VariablesTreeInfosFactory(object):
def __init__(self):
self.Root = None
def GetRoot(self):
return self.Root
def SetRoot(self, context, *args):
self.Root = _VariablesTreeItemInfos(
*([''] + _translate_args(
[class_extraction, _StringValue] + [_BoolValue] * 2,
args) + [[]]))
def AddVariable(self, context, *args):
if self.Root is not None:
self.Root.variables.append(_VariablesTreeItemInfos(
*(_translate_args(
[_StringValue, class_extraction, _StringValue] +
[_BoolValue] * 2, args) + [[]])))
class POUVariablesCollector(XSLTModelQuery):
def __init__(self, controller):
XSLTModelQuery.__init__(self,
controller,
"pou_variables.xslt",
[(name, self.FactoryCaller(name))
for name in ["SetRoot", "AddVariable"]])
def FactoryCaller(self, funcname):
def CallFactory(*args):
return getattr(self.factory, funcname)(*args)
return CallFactory
def Collect(self, root, debug):
self.factory = VariablesTreeInfosFactory()
self._process_xslt(root, debug)
res = self.factory.GetRoot()
self.factory = None
return res