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))
[-------------------------------------------------------------]
<?xml version="1.0"?>
<xsl:stylesheet xmlns:exsl="http://exslt.org/common" xmlns:xhtml="http://www.w3.org/1999/xhtml" xmlns:ppx="http://www.plcopen.org/xml/tc6_0201" xmlns:ns="beremiz" xmlns:xsl="http://www.w3.org/1999/XSL/Transform" extension-element-prefixes="ns" version="1.0" exclude-result-prefixes="ns">
<xsl:output method="xml"/>
<xsl:param name="instance_path"/>
<xsl:variable name="project" select="ns:GetProject()"/>
<xsl:variable name="stdlib" select="ns:GetStdLibs()"/>
<xsl:variable name="extensions" select="ns:GetExtensions()"/>
<xsl:variable name="all_types" select="($project | $stdlib | $extensions)/ppx:types"/>
<xsl:template name="element_name">
<xsl:param name="path"/>
<xsl:choose>
<xsl:when test="contains($path,'.')">
<xsl:value-of select="substring-before($path,'.')"/>
</xsl:when>
<xsl:otherwise>
<xsl:value-of select="$path"/>
</xsl:otherwise>
</xsl:choose>
</xsl:template>
<xsl:template name="next_path">
<xsl:param name="path"/>
<xsl:choose>
<xsl:when test="contains($path,'.')">
<xsl:value-of select="substring-after($path,'.')"/>
</xsl:when>
</xsl:choose>
</xsl:template>
<xsl:template match="ppx:project">
<xsl:variable name="config_name">
<xsl:call-template name="element_name">
<xsl:with-param name="path" select="$instance_path"/>
</xsl:call-template>
</xsl:variable>
<xsl:apply-templates select="ppx:instances/ppx:configurations/ppx:configuration[@name=$config_name]">
<xsl:with-param name="element_path">
<xsl:call-template name="next_path">
<xsl:with-param name="path" select="$instance_path"/>
</xsl:call-template>
</xsl:with-param>
</xsl:apply-templates>
</xsl:template>
<xsl:template match="ppx:configuration">
<xsl:param name="element_path"/>
<xsl:choose>
<xsl:when test="$element_path!=''">
<xsl:variable name="child_name">
<xsl:call-template name="element_name">
<xsl:with-param name="path" select="$element_path"/>
</xsl:call-template>
</xsl:variable>
<xsl:apply-templates select="ppx:resource[@name=$child_name] | ppx:globalVars/ppx:variable[@name=$child_name]/ppx:type/*[self::ppx:derived or self::ppx:struct or self::ppx:array]">
<xsl:with-param name="element_path">
<xsl:call-template name="next_path">
<xsl:with-param name="path" select="$element_path"/>
</xsl:call-template>
</xsl:with-param>
</xsl:apply-templates>
</xsl:when>
<xsl:otherwise>
<xsl:value-of select="ns:ConfigTagName(@name)"/>
</xsl:otherwise>
</xsl:choose>
</xsl:template>
<xsl:template match="ppx:resource">
<xsl:param name="element_path"/>
<xsl:choose>
<xsl:when test="$element_path!=''">
<xsl:variable name="child_name">
<xsl:call-template name="element_name">
<xsl:with-param name="path">
<xsl:value-of select="$element_path"/>
</xsl:with-param>
</xsl:call-template>
</xsl:variable>
<xsl:apply-templates select="ppx:pouInstance[@name=$child_name] | ppx:task/ppx:pouInstance[@name=$child_name] | ppx:globalVars/ppx:variable[@name=$child_name]/ppx:type/*[self::ppx:derived or self::ppx:struct or self::ppx:array]">
<xsl:with-param name="element_path">
<xsl:call-template name="next_path">
<xsl:with-param name="path" select="$element_path"/>
</xsl:call-template>
</xsl:with-param>
</xsl:apply-templates>
</xsl:when>
<xsl:otherwise>
<xsl:value-of select="ns:ResourceTagName(ancestor::ppx:configuration/@name, @name)"/>
</xsl:otherwise>
</xsl:choose>
</xsl:template>
<xsl:template match="ppx:pouInstance">
<xsl:param name="element_path"/>
<xsl:variable name="type_name">
<xsl:value-of select="@typeName"/>
</xsl:variable>
<xsl:apply-templates select="$all_types/ppx:pous/ppx:pou[@name=$type_name] | $all_types/ppx:dataTypes/ppx:dataType[@name=$type_name]">
<xsl:with-param name="element_path" select="$element_path"/>
</xsl:apply-templates>
</xsl:template>
<xsl:template match="ppx:pou">
<xsl:param name="element_path"/>
<xsl:choose>
<xsl:when test="$element_path!=''">
<xsl:variable name="child_name">
<xsl:call-template name="element_name">
<xsl:with-param name="path" select="$element_path"/>
</xsl:call-template>
</xsl:variable>
<xsl:apply-templates select="ppx:interface/*/ppx:variable[@name=$child_name]/ppx:type/*[self::ppx:derived or self::ppx:struct or self::ppx:array]">
<xsl:with-param name="element_path">
<xsl:call-template name="next_path">
<xsl:with-param name="path" select="$element_path"/>
</xsl:call-template>
</xsl:with-param>
</xsl:apply-templates>
<xsl:apply-templates select="ppx:actions/ppx:action[@name=$child_name] | ppx:transitions/ppx:transition[@name=$child_name]"/>
</xsl:when>
<xsl:otherwise>
<xsl:variable name="name">
<xsl:value-of select="@name"/>
</xsl:variable>
<xsl:value-of select="ns:PouTagName($name)"/>
</xsl:otherwise>
</xsl:choose>
</xsl:template>
<xsl:template match="ppx:action">
<xsl:value-of select="ns:ActionTagName(ancestor::ppx:pou/@name, @name)"/>
</xsl:template>
<xsl:template match="ppx:transition">
<xsl:value-of select="ns:TransitionTagName(ancestor::ppx:pou/@name, @name)"/>
</xsl:template>
<xsl:template match="ppx:dataType">
<xsl:param name="element_path"/>
<xsl:apply-templates select="ppx:baseType/*[self::ppx:derived or self::ppx:struct or self::ppx:array]">
<xsl:with-param name="element_path" select="$element_path"/>
</xsl:apply-templates>
</xsl:template>
<xsl:template match="ppx:derived">
<xsl:param name="element_path"/>
<xsl:variable name="type_name">
<xsl:value-of select="@name"/>
</xsl:variable>
<xsl:apply-templates select="$all_types/ppx:pous/ppx:pou[@name=$type_name] | $all_types/ppx:dataTypes/ppx:dataType[@name=$type_name]">
<xsl:with-param name="element_path" select="$element_path"/>
</xsl:apply-templates>
</xsl:template>
<xsl:template match="ppx:array">
<xsl:param name="element_path"/>
<xsl:apply-templates select="ppx:baseType/*[self::ppx:derived or self::ppx:struct or self::ppx:array]">
<xsl:with-param name="element_path" select="$element_path"/>
</xsl:apply-templates>
</xsl:template>
<xsl:template match="ppx:struct">
<xsl:param name="element_path"/>
<xsl:variable name="child_name">
<xsl:call-template name="element_name">
<xsl:with-param name="path" select="$element_path"/>
</xsl:call-template>
</xsl:variable>
<xsl:apply-templates select="ppx:variable[@name=$child_name]/ppx:type/*[self::ppx:derived or self::ppx:struct or self::ppx:array]">
<xsl:with-param name="element_path">
<xsl:call-template name="next_path">
<xsl:with-param name="path" select="$element_path"/>
</xsl:call-template>
</xsl:with-param>
</xsl:apply-templates>
</xsl:template>
</xsl:stylesheet>