topic Re: CIM Access: Layer doesn't support "getDefinition", is actually a MappingLayer (undocumented). in Python Questions

CIM Access: Layer doesn't support "getDefinition", is actually a MappingLayer (undocumented).

AlfredBaldenweck — Wed, 04 Oct 2023 23:10:43 GMT

Pro 2.9.5

Touching up a tool I wrote last year, including migrating it from a scripting tool (ATBX) to a python toolbox (PYT). Part of the workflow involves accessing CIM, using a layer from the map as an input.

The tool runs great in the ATBX.

cim_lyr= FC.getDefinition('V2')

However, something REALLY WEIRD happens in the PYT.

I get the following error message:

AttributeError: 'MappingLayerObject' object has no attribute 'getDefinition'

Hmm, let's investigate this and make sure that I'm putting in what I think I am.

In the map:

aprx = arcpy.mp.ArcGISProject("CURRENT") mp = aprx.activeMap lay = mp.listLayers("colton*") lay= lay[0] print(type(lay)) #<class 'arcpy._mp.Layer'> print(dir(lay)) # ['URI', '__class__', '__delattr__', '__dict__', '__dir__', '__doc__', # '__eq__', '__format__', '__from_scripting_arc_object__', '__ge__', # '__getattribute__', '__gt__', '__hash__', '__init__', '__init_subclass__', # '__le__', '__lt__', '__module__', '__ne__', '__new__', '__reduce__', # '__reduce_ex__', '__repr__', '__setattr__', '__sizeof__', '__str__', # '__subclasshook__', '__weakref__', '_arc_object', 'brightness', # 'connectionProperties', 'contrast', 'dataSource', 'definitionQuery', # 'disableTime', 'enableTime', 'extrusion', 'getDefinition', # 'getSelectionSet', 'is3DLayer', 'isBasemapLayer', 'isBroken', # 'isFeatureLayer', 'isGroupLayer', 'isNetworkAnalystLayer', # 'isNetworkDatasetLayer', 'isRasterLayer', 'isSceneLayer', 'isTimeEnabled', # 'isWebLayer', 'listDefinitionQueries', 'listLabelClasses', 'listLayers', # 'listTables', 'longName', 'maxThreshold', 'metadata', 'minThreshold', # 'name', 'saveACopy', 'setDefinition', 'setSelectionSet', 'showLabels', # 'supports', 'symbology', 'time', 'transparency', # 'updateConnectionProperties', 'updateDefinitionQueries', # 'updateLayerFromJSON', 'visible']

Okay, so clearly a layer and definitely supports getDefinition.

Cool. Let's check in the ATBX script.

arcpy.AddMessage(type(FC)) #<class 'arcpy._mp.Layer'> arcpy.AddMessage(dir(FC)) # ['URI', '__class__', '__delattr__', '__dict__', '__dir__', '__doc__', # '__eq__', '__format__', '__from_scripting_arc_object__', '__ge__', # '__getattribute__', '__gt__', '__hash__', '__init__', '__init_subclass__', # '__le__', '__lt__', '__module__', '__ne__', '__new__', '__reduce__', # '__reduce_ex__', '__repr__', '__setattr__', '__sizeof__', '__str__', # '__subclasshook__', '__weakref__', '_arc_object', 'brightness', # 'connectionProperties', 'contrast', 'dataSource', 'definitionQuery', # 'disableTime', 'enableTime', 'extrusion', 'getDefinition', # 'getSelectionSet', 'is3DLayer', 'isBasemapLayer', 'isBroken', # 'isFeatureLayer', 'isGroupLayer', 'isNetworkAnalystLayer', # 'isNetworkDatasetLayer', 'isRasterLayer', 'isSceneLayer', 'isTimeEnabled', # 'isWebLayer', 'listDefinitionQueries', 'listLabelClasses', 'listLayers', # 'listTables', 'longName', 'maxThreshold', 'metadata', 'minThreshold', # 'name', 'saveACopy', 'setDefinition', 'setSelectionSet', 'showLabels', # 'supports', 'symbology', 'time', 'transparency', # 'updateConnectionProperties', 'updateDefinitionQueries', # 'updateLayerFromJSON', 'visible']

Still supports getDefinition.

Let's check the PYT.

arcpy.AddMessage(type(FC)) <class 'MappingLayerObject'> arcpy.AddMessage(dir(FC)) # ['GetCimJSONString', 'SetCimJSONString', 'URI', 'UpdateLayerFromJSON', # '_XML', '__class__', '__delattr__', '__dir__', '__doc__', '__eq__', # '__format__', '__ge__', '__getattribute__', '__gt__', '__hash__', # '__init__', '__init_subclass__', '__le__', '__lt__', '__ne__', '__new__', # '__reduce__', '__reduce_ex__', '__repr__', '__setattr__', '__sizeof__', # '__str__', '__subclasshook__', '_id', '_pUnk', 'brightness', # 'connectionProperties', 'contrast', 'dataSource', 'definitionQuery', # 'disableTime', 'enableTime', 'extrusion', 'getSelectionSet', 'is3DLayer', # 'isBasemapLayer', 'isBroken', 'isFeatureLayer', 'isGroupLayer', # 'isLayerSame', 'isNetworkAnalystLayer', 'isNetworkDatasetLayer', # 'isRasterLayer', 'isSceneLayer', 'isTimeEnabled', 'isWebLayer', # 'listDefinitionQueries', 'listLabelClasses', 'listLayers', 'listTables', # 'longName', 'maxThreshold', 'metadata', 'minThreshold', 'name', # 'saveACopy', 'setSelectionSet', 'showLabels', 'supports', 'symbology', # 'time', 'transparency', 'updateConnectionProperties', # 'updateDefinitionQueries', 'visible']

Definitely does not support getDefinition. But it has GetCimJSONString, which only appears to be documented in @SamSzotkowski 's post here. (That exact query in Google will yield the same post, as well as site that is actually AliExpress)

He writes, as I have also found, that instead of getting a layer object, we get a mappinglayer object. I can't find any documentation for this.

'''ATBX''' inFCs = GetParameter(2) arcpy.AddMessage(type(inFCs)) # <class 'list'> arcpy.AddMessage(type(inFCs[0])) # <class 'arcpy._mp.Layer'> return '''PYT''' arcpy.AddMessage(type(parameters[2].value)) #<class 'geoprocessing value table object'> arcpy.AddMessage(type(parameters[2].value.GetTrueValue(0,0))) #<class 'MappingLayerObject'> # I also checked with .GetTrueRow(0), etc.

So uh. What is a mappinglayer and where is anything written down about it?

What about a python toolbox causes a multivalue FeatureLayer parameter to be considered a value table, and the features within to be "MappingLayer"s instead of normal layers? And seriously, why is this not written down anywhere? Why is this not mentioned on the CIM Access Documentation?

Like, cool, I guess I can rewrite the code to use JSON instead of the CIM object. But it would have been great to have been warned about this beforehand.

Re: CIM Access: Layer doesn't support "getDefinition", is actually a MappingLayer (undocumented).

JohannesLindner — Thu, 05 Oct 2023 19:44:31 GMT

Interesting...

Just a quick test:

# -*- coding: utf-8 -*- import arcpy import json class Toolbox(object): def __init__(self): """Define the toolbox (the name of the toolbox is the name of the .pyt file).""" self.label = "Toolbox" self.alias = "toolbox" # List of tool classes associated with this toolbox self.tools = [Tool] def msg(txt=""): arcpy.AddMessage(str(txt)) class Tool(object): def __init__(self): self.label = "Tool" def getParameterInfo(self): return [ arcpy.Parameter(name="p0", displayName="Layer", datatype="GPFeatureLayer"), arcpy.Parameter(name="p1", displayName="Layer Multi", datatype="GPFeatureLayer", multiValue=True), ] def execute(self, parameters, messages): # print parameter types for p in parameters: msg(f"parameter name: {p.displayName}") msg(f"\tparameter value: {p.value}") msg(f"\tvalue type: {type(p.value)}") if p.multiValue: msg(f"\ttype of first value: {type(p.value.GetTrueValue(0,0))}") # get the actual arcpy.mp.Layer object mapping_layer = parameters[0].value layer = arcpy.mp.ArcGISProject("current").activeMap.listLayers(mapping_layer.name)[0] # examine similarities and differences between arcpy.mp.Layer and MappingLayerObject l_dir = set(dir(layer)) ml_dir = set(dir(mapping_layer)) msg("Available in both:") for a in sorted(l_dir.intersection(ml_dir)): msg(f"\t{a}") msg("Not available in MappingLayerObject:") for a in sorted(l_dir - ml_dir): msg(f"\t{a}") msg("Not available in arcpy.mp.Layer:") for a in sorted(ml_dir - l_dir): msg(f"\t{a}") # get the MappingLayerObject's CIM d = json.loads(mapping_layer.GetCimJSONString()) msg("GetCimJSONString keys:") for k in sorted(d.keys()): msg(f"\t{k}") # try playing with it (doesn't work) d["visibility"] = False mapping_layer.SetCimJSONString(json.dumps(d)) # try manipulating the cim (this works) cim = layer.getDefinition("V3") cim.visibility = False layer.setDefinition(cim)

parameter name: Layer
    parameter value: <MappingLayerObject object at 0x0000020F36A80F60>
    value type: <class 'MappingLayerObject'>
parameter name: Layer Multi
    parameter value: TestPoints
    value type: <class 'geoprocessing value table object'>
    type of first value: <class 'MappingLayerObject'>
Available in both:
    URI
    __class__
    __delattr__
    __dir__
    __doc__
    __eq__
    __format__
    __ge__
    __getattribute__
    __gt__
    __hash__
    __init__
    __init_subclass__
    __le__
    __lt__
    __ne__
    __new__
    __reduce__
    __reduce_ex__
    __repr__
    __setattr__
    __sizeof__
    __str__
    __subclasshook__
    brightness
    connectionProperties
    contrast
    dataSource
    definitionQuery
    disableTime
    enableTime
    extrusion
    getSelectionSet
    is3DLayer
    isBasemapLayer
    isBroken
    isFeatureLayer
    isGroupLayer
    isNetworkAnalystLayer
    isNetworkDatasetLayer
    isRasterLayer
    isSceneLayer
    isTimeEnabled
    isWebLayer
    listDefinitionQueries
    listLabelClasses
    listLayers
    listTables
    longName
    maxThreshold
    metadata
    minThreshold
    name
    saveACopy
    setSelectionSet
    showLabels
    supports
    symbology
    time
    transparency
    updateConnectionProperties
    updateDefinitionQueries
    visible
Not available in MappingLayerObject:
    __dict__
    __from_scripting_arc_object__
    __module__
    __weakref__
    _arc_object
    getDefinition
    setDefinition
    updateLayerFromJSON
Not available in arcpy.mp.Layer:
    GetCimJSONString
    SetCimJSONString
    UpdateLayerFromJSON
    _XML
    _id
    _pUnk
    isLayerSame
GetCimJSONString keys:
    allowDrapingOnIntegratedMesh
    autoGenerateFeatureTemplates
    blendingMode
    description
    displayCacheType
    displayFiltersType
    enableDisplayFilters
    expanded
    featureBlendingMode
    featureCacheType
    featureElevationExpression
    featureTable
    featureTemplates
    htmlPopupEnabled
    labelClasses
    layerElevation
    layerType
    maxDisplayCacheAge
    metadataURI
    name
    popupInfo
    refreshRate
    refreshRateUnit
    renderer
    scaleSymbols
    selectable
    serviceLayerID
    showLegends
    showPopups
    snappable
    sourceModifiedTime
    symbolLayerDrawing
    type
    uRI
    useSourceMetadata
    visibility

multiValue doesn't seem to be the culprit. The single parameter value is a MappingLayerObject, too.
they have many similarities to "normal" layers. The significant differences:
- the way to access the cim properties (Python objects vs JSON)
- MappingObjectLayer doesn't seem to be derived from an arcobject (it doesn't have the _arcobject property). Most arcpy classes are just wrappers around ArcObjects, MappingLayerObject might be different. I did not want to dive into the arcpy source code, though...
You can get the cim properties from the JSON, but setting them to the MappingLayerObject didn't work (but I also didn't try to make it work...)
Your best bet is probably to use the name attribute to get the arcpy._mp.Layer from the active map like I did in line 43. Manipulating this object's cim does appear to work.

Re: CIM Access: Layer doesn't support "getDefinition", is actually a MappingLayer (undocumented).

AlfredBaldenweck — Thu, 05 Oct 2023 20:08:12 GMT

Yeah, the multi-value complaint is extraneous; I just hate that it returns a value table instead a list like multivalue parameters do in ATBXs.

Just very confused as to why PYTs don't bring in Layer objects from parameters. (and why it's not documented!?)

In this case, I just needed to read the CIM, but I shudder at the idea of updating it this way.

Re: CIM Access: Layer doesn't support "getDefinition", is actually a MappingLayer (undocumented).

JohannesLindner — Fri, 06 Oct 2023 09:22:38 GMT

Seeing as it's not documented, I'd wager it's not something that users are meant to interact with. Might be an oversight/bug.

Just get the arcpy._mp.Layer object from the map using the MappingLayerObject.name property and do your CIM manipulations like normal.

Re: CIM Access: Layer doesn't support "getDefinition", is actually a MappingLayer (undocumented).

SamSzotkowski — Mon, 23 Oct 2023 18:33:36 GMT

Indeed I think one of the "intended" ways for you to alter layer properties in a PYT is via the postExecute method, matching the Layer in the active map to the tool's input by name, though even in their example snippet they make the shaky assumption that all layers have unique names (best practice though it may be).

I'd hoped when I saw they added this method in 3.0 that it meant we no longer had to do black magic to alter layer properties, but c'est la vie. In truth I don't understand what the point of postExecute is, as far as I know everything you can do in there you can do in regular execute.