For example, suppose you want to know exactly where a TextureOp is located in the construction history (aka the operator stack).

A TextureOp object is nested under a cluster, not under the primitive, so you can’t use Primitive.ConstructionHistory.

Try it, and you’ll see that the TextureOp does not show up.

from siutils import sisel	# Selection
from siutils import log		# LogMessage

for x in sisel(0).ActivePrimitive.ConstructionHistory:
	if x.BelongsTo( "MarkerOperators" ):
		sMarker = x.type

	log( "%s -> %s" %(sMarker,x.name) )

Instead, you’ll have to use DataRepository.GetConnectionStackInfo, which returns an XML description of the operator stack. The XML looks something like this (note that I had to use <_object> to stop wordpress from removing the <object> tag in my XML):

<?xml version="1.0"?>
<connections>
 	<connection>
 		<datacopy>0x000000001D7B7330</datacopy>
 		<hidden>false</hidden>
 		<_object>sphere.polymsh.modelingmarker</_object>
 		<objectid>533</objectid>
 		<region>2</region>
 		<type>out</type>
 	</connection>
 	<connection>
 		<datacopy>0x000000001F4C9F40</datacopy>
 		<hidden>false</hidden>
 		<_object>sphere.polymsh.cls.sample.clslist.Texture_Coordinates_AUTO.localprops.ClsProp.Texture_Projection.TextureOp</_object>
 		<objectid>571</objectid>
 		<region>2</region>
 		<type>out</type>
 	</connection>
 	<connection>
 		<datacopy>0x000000001C215310</datacopy>
 		<hidden>false</hidden>
 		<_object>sphere.polymsh.bulgeop</_object>
 		<objectid>532</objectid>
 		<region>2</region>
 		<type>in</type>
 	</connection>
</connections>

Here’s a Python snippet that uses ElementTree to parse the connectionstack XML and then log the TextureOp tooltip that says where the op reads from the stack:

from siutils import si		# Application
from siutils import sidict	# Dictionary
from siutils import sisel	# Selection
from siutils import siuitk	# XSIUIToolkit
from siutils import siut	# XSIUtils
from siutils import log		# LogMessage
from siutils import disp	# win32com.client.Dispatch
from siutils import C		# win32com.client.constants

from xml.etree import ElementTree as ET

prim = sisel(0).ActivePrimitive if si.ClassName(sisel(0)) ==  'X3DObject' else sisel(0)


stackInfo = siut.DataRepository.GetConnectionStackInfo( prim )
#log( stackInfo )
connections = ET.XML(stackInfo)
currentMarker =''

#
# Read XML into a list of tuples that looks like this:
# ('sphere.polymsh.secondaryshapemarker', 'sphere.polymsh.secondaryshapemarker')
# ('sphere.polymsh.postsimulationmarker', 'sphere.polymsh.postsimulationmarker')
# ('sphere.polymsh.simulationmarker', 'sphere.polymsh.simulationmarker')
# ('sphere.polymsh.ICETree', 'sphere.polymsh.simulationmarker')
# ('sphere.polymsh.animationmarker', 'sphere.polymsh.animationmarker')
# ('sphere.polymsh.shapemarker', 'sphere.polymsh.shapemarker')
# ('sphere.polymsh.modelingmarker', 'sphere.polymsh.modelingmarker')
# ('sphere.polymsh.cls.sample.clslist.Texture_Coordinates_AUTO.localprops.ClsProp.Texture_Projection.TextureOp', 'sphere.polymsh.modelingmarker')
# ('sphere.polymsh.geom', 'sphere.polymsh.modelingmarker')
#
currentMarker = '%s.%s' %(prim.FullName, 'above-secondaryshapemarker')
ops = []
for connection in connections:
		o = connection.find('object').text
		bHidden = connection.find('hidden').text == 'true'
		
		if o == currentMarker or bHidden:
			continue
	
		if o.endswith('marker'):
			currentMarker = o

		ops.append( (o, currentMarker ) )
	
	
#
# Go through list of tuples and find 
# where TextureOp reads
#
for i in range( len(ops) ):
	oOp = sidict.GetObject( ops[i][0] )
	if oOp.type == 'TextureOp':
		print oOp.Name
		if i == len(ops):
			sRead = "(reading from bottom of primitive stack)"
		else:
			sRead = '(reading just above %s)' %(sidict.GetObject( ops[i+1][0] ).Name)
			
		print '%s %s' %(oOp.Name,sRead)
		# TextureOp (reading just above Bulge Op)