Indesign Applescript Placed Object Layer Visibilty Override

Question

Hi, trying to programmatically control layer visibility of placed objects (either AI or other ID files) in a multi-page Indesign document.  Have looked all over the dictionary but can't seem to figure a way to reference the layers.
Would someone have an example of how to do this in Applescript?  (Please, not javascript, will convert one day but for now am staying with AS.)
Thanks!

Answer 1

Thanks, Mary, your suggestion has put me on a good path, but I'm still having some trouble.
I have several similar documents, each having multiple pages with one placed item per page that are linked, not embedded.  Each of those placed items may or may not have a layer with a specific name.  I'm trying to iterate through the links and toggle visibility of the layers within the placed objects as needed.
Ultimately the script would:
    Cycle through all links in the target doc.
        Get a list of all layers in the current link of the cycle.
        Cycle through a list of layer names to check.
            Set the desired layer to visible, all others in the list to not visible.
            (This could be with a string var that was the same as the desired entry in the list, or a numeric index var to compare with where the counter was in its cycle)
Here's a verbose example of what I've got so far.  It assumes the target document is already open...
# With which app are we working?
tell application "Adobe InDesign CC 2014"
    # With which document are we working?
    set theDocName to "My Indesign Document"
    # Which layer do we want to be visible?   
    set theDesiredLayer to "My Desired Visible Layer"
    # Set the Document ID of the chosen document
    set theDocID to document named theDocName
    # Work with the chosen document
    tell theDocID
        # Create an object of all links of the chosen document
        set theDocLinks to links of theDocID
        # Set the count of all links in the chosen document
        set theDocLinksCount to count of theDocLinks
        # Cycle through all the linked objects
        repeat with i from 1 to theDocLinksCount
            # Create an object of the current link
            set theCurLink to item i of theDocLinks
            # Set the name of the current link
            set theLinkName to name of theCurLink
            # Create an object of the parent of the current link
            set theLinkParent to parent of theCurLink
            # Create an object of the graphic layer options of the parent of the current link
            set theGraphicLayerOptions to graphic layer options of theLinkParent
            # Get a count of the layers in the current link
            set theLayerCount to count of graphic layers of theGraphicLayerOptions
            # Cycle through the layers in the current link
            repeat with j from 1 to theLayerCount
                # Create an object of the current layer
                set theLayer to item j of graphic layers of theGraphicLayerOptions
                # THIS FAILS
                set theLayerName to name of theLayer
                log "Layer: '" & theLayerName & "' ~ Visible: '" & current visibility of graphic layer theLayerName of theOptions
                # THIS WORKS ONLY UNDER CERTAIN CONDITIONS
                set current visibility of graphic layer theDesiredLayer of theGraphicLayerOptions to true
            end repeat
        end repeat
    end tell
end tell
The part that works does so only when I let it act on specific links (based on theLinkName).  If the link has no such layer, it bombs (as expected).
I'd really rather just iterate through the layers of each link and take action based on whether or not my target layer exists in that link.  For that to happen, I need to be able to access the name of the layer.
When cycling through the layers,
    set theLayer to item j of graphic layers of theGraphicLayerOptions
*should* return a graphic layer object, which has a name property that I could then use for comparison.  But that always fails.
I've also tried other properties of the graphic layer object such as parent, object reference, etc. It always bombs out when I try to work with the layer object.
The obvious conclusion is that I'm not really creating a graphic layer object, but according to the dictionary it seems this should work.
Any ideas what I'm doing wrong?
Thanks!