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
# -------------------------------------------------------------------------------
# Helpers object for generating pou var list
# -------------------------------------------------------------------------------
class _VariableInfos(object):
__slots__ = ["Name", "Class", "Option", "Location", "InitialValue",
"Edit", "Documentation", "Type", "Tree", "Number"]
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 _VariableInfos(*[getattr(self, attr) for attr in self.__slots__])
class VariablesInfosFactory(object):
""" Helpers object for generating pou var list """
def __init__(self, variables):
self.Variables = variables
self.TreeStack = []
self.Type = None
self.Dimensions = None
def SetType(self, context, *args):
self.Type = args[0][0]
def GetType(self):
if len(self.Dimensions) > 0:
return ("array", self.Type, self.Dimensions)
return self.Type
def GetTree(self):
return (self.TreeStack.pop(-1), self.Dimensions)
def AddDimension(self, context, *args):
self.Dimensions.append(tuple(
_translate_args([_StringValue] * 2, args)))
def AddTree(self, context, *args):
self.TreeStack.append([])
self.Dimensions = []
def AddVarToTree(self, context, *args):
var = (args[0][0], self.Type, self.GetTree())
self.TreeStack[-1].append(var)
def AddVariable(self, context, *args):
self.Variables.append(_VariableInfos(*(
_translate_args([_StringValue] * 5 + [_BoolValue] + [_StringValue], args) +
[self.GetType(), self.GetTree()])))
class VariableInfoCollector(XSLTModelQuery):
def __init__(self, controller):
XSLTModelQuery.__init__(self,
controller,
"variables_infos.xslt",
[(name, self.FactoryCaller(name))
for name in [
"SetType",
"AddDimension",
"AddTree",
"AddVarToTree",
"AddVariable"]])
def FactoryCaller(self, funcname):
def CallFactory(*args):
return getattr(self.factory, funcname)(*args)
return CallFactory
def Collect(self, root, debug, variables, tree):
self.factory = VariablesInfosFactory(variables)
self._process_xslt(root, debug, tree=str(tree))
res = self.factory
self.factory = None
return res