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))
[-------------------------------------------------------------]
# the platform name (PyV8, smjs, Mozilla, IE6, Opera, Safari etc.)
platform = '' # to be updated by app, on compile
# a dictionary of module override names (platform-specific)
overrides = {} # to be updated by app, on compile
# the remote path for loading modules
loadpath = None
stacktrace = None
appname = None
def setloadpath(lp):
global loadpath
loadpath = lp
def setappname(an):
global appname
appname = an
def getloadpath():
return loadpath
def addoverride(module_name, path):
overrides[module_name] = path
def addstack(linedebug):
JS("""
if (pyjslib.bool((sys.stacktrace === null))) {
sys.stacktrace = new pyjslib.List([]);
}
sys.stacktrace.append(linedebug);
""")
def popstack():
JS("""
sys.stacktrace.pop()
""")
def printstack():
JS("""
var res = '';
var __l = sys.stacktrace.__iter__();
try {
while (true) {
var l = __l.next();
res += ( l + '\\n' ) ;
}
} catch (e) {
if (e != pyjslib.StopIteration) {
throw e;
}
}
return res;
""")