Maya 2020 reproducable case of reference edits for string attributes stripping whitespaces in a string value

maya_get_reference_edits_string_bug.py

from maya import cmds, mel
import maya.OpenMaya as om

# Point filepath to a mayaAscii file that has at least one transform node in it
filepath = r"path/to/maya_scene_to_reference.ma"

# Reference the file
nodes = cmds.file(filepath, reference=True, type="mayaAscii", ignoreVersion=True, gl=True, mergeNamespacesOnClash=True, namespace="camera", options="v=0;", returnNewNodes=True)
ref = cmds.ls(nodes, type="reference")[0]


# Add attribute to the node and set the value
transform = cmds.ls(nodes, type="transform")[0]
cmds.addAttr(transform, longName="myAttr", dataType="string")
cmds.setAttr(transform + ".myAttr", "hello world. testing with many      whitespaces.", type="string")


# Example:
# maya.cmds
print cmds.referenceQuery(ref, editStrings=True, editCommand="setAttr")[0]
# setAttr |camera:camera.myAttr -type "string" "hello world. testing with many whitespaces."
# Above is invalid, note the missing whitespaces.


# Example:
# mel
print mel.eval('referenceQuery -editStrings -editCommand "setAttr" "{}"'.format(ref))[0]
# setAttr |camera:camera.myAttr -type "string" "hello world. testing with many whitespaces."
# Above is invalid, same issue.


# Example
# maya.OpenMaya API
sel = om.MSelectionList()
sel.add(ref)
o_ref = om.MObject()
sel.getDependNode(0, o_ref)         
it_edit = om.MItEdits(o_ref)
while not it_edit.isDone():
    if it_edit.currentEditType() == om.MEdit.kSetAttrEdit:
    
        # Directly from MItEdits
        print it_edit.currentEditString()
        # setAttr "camera:camera.myAttr" -type "string" "hello world. testing with many whitespaces."
        
        # Using MEdit.getString()
        edit = it_edit.edit()
        print edit.getString()
        # setAttr "camera:camera.myAttr" -type "string" "hello world. testing with many whitespaces."
        
        # Using MSetAttrEdit
        set_attr_edit = it_edit.setAttrEdit()
        print set_attr_edit.getString()
        # setAttr "camera:camera.myAttr" -type "string" "hello world. testing with many whitespaces."
    
    it_edit.next()
    
    
# Example:
# maya.OpenMaya.MPlug.getSetAttrCmds() - get edits directly from reference node "edits" attribute
sel = om.MSelectionList()
sel.add(ref)
o_ref = om.MObject()
sel.getDependNode(0, o_ref)         
fn_dep = om.MFnDependencyNode(o_ref)
edits_plug = fn_dep.findPlug("edits")

commands = []
edits_plug.getSetAttrCmds(commands, om.MPlug.kAll, True)
print commands
# This is invalid because there is no valid data as long as the reference is loaded

ref_filename_w_copy_number = cmds.referenceQuery(ref, filename=True)
cmds.file(ref_filename_w_copy_number, unloadReference=True)

commands = []
edits_plug.getSetAttrCmds(commands, om.MPlug.kAll, True)
print commands
print next(c for c in commands if "hello world." in c)    # print only the line related to the setAttr
# 2 "|camera:camera" "myAttr" " -type \"string\" \"hello world. testing with many      whitespaces.\""
# This actually DOES correctly output the string - but I'd rather have it from something else with edits
# that are more trivial to parse and work whilst the reference is loaded.