[artLayer].id returns undefined on windows, works fine on mac

[jonnyr39056025]

I've written a script that at some point calls .id on an artlayer to get that layer's unique ID to reference later. I've developed this on a mac and it works perfectly on a mac. However, I need this to be cross platform, and on windows calling .id returns undefined instead of the unique ID, throwing an error. I'm running this on Photoshop CS6.

I need the ID as I want to select specific layers, and want to be sure the correct layers are selected even if they share a name with another layer, or are nested inside a layerSet.

My script's below, does anyone know why the behaviour is different here, or know of a fix, workaround or different approach I can take to get the same results?

Thanks

#target photoshop

///////////////////////

// SETUP //////////////

///////////////////////

// Save the current preferences

var startRulerUnits = app.preferences.rulerUnits;  

var startTypeUnits = app.preferences.typeUnits;

var startDisplayDialogs = app.displayDialogs;

// Set Adobe Photoshop CS6 to use pixels and display no dialogs

app.preferences.rulerUnits = Units.PIXELS;

app.preferences.typeUnits = TypeUnits.PIXELS;

app.displayDialogs = DialogModes.NO;

///////////////////////

// FUNCTIONS //////////

///////////////////////

// returns currently selected layers as an array

function getSelectedLayers() {

// =======================================================

    var idGrp = stringIDToTypeID( "groupLayersEvent" );

    var descGrp = new ActionDescriptor();

    var refGrp = new ActionReference();

    refGrp.putEnumerated(charIDToTypeID( "Lyr " ), charIDToTypeID( "Ordn" ),charIDToTypeID( "Trgt" ));

    descGrp.putReference(charIDToTypeID( "null" ), refGrp );

    executeAction( idGrp, descGrp, DialogModes.ALL );

    var resultLayers = new Array();

    for (var ix = 0; ix < app.activeDocument.activeLayer.layers.length; ix++) {

        resultLayers.push(app.activeDocument.activeLayer.layers[ix]);

    }

    var id8 = charIDToTypeID( "slct" );

    var desc5 = new ActionDescriptor();

    var id9 = charIDToTypeID( "null" );

    var ref2 = new ActionReference();

    var id10 = charIDToTypeID( "HstS" );

    var id11 = charIDToTypeID( "Ordn" );

    var id12 = charIDToTypeID( "Prvs" );

    ref2.putEnumerated( id10, id11, id12 );

    desc5.putReference( id9, ref2 );

    executeAction( id8, desc5, DialogModes.NO );

    return resultLayers;

} 

// returns bounds of layer

function visibleBounds(layer) {

// =======================================================

    doc.activeLayer = layer;

    return doc.activeLayer.bounds;

}

// difference between two numbers plus boolean for determining direction

function difference(num1, num2) {

    if (num1 > num2) {

        return [num1 - num2, false];

    } else {

        return [num2 - num1, true];

    }

}

function selectLayerById(id, add){  

    var ref = new ActionReference(); 

        ref.putIdentifier(charIDToTypeID('Lyr '), id); 

    var desc = new ActionDescriptor(); 

        desc.putReference(charIDToTypeID("null"), ref ); 

    if(add) desc.putEnumerated( stringIDToTypeID( "selectionModifier" ), stringIDToTypeID( "selectionModifierType" ), stringIDToTypeID( "addToSelection" ) );  

    desc.putBoolean( charIDToTypeID( "MkVs" ), false );  

    try{ 

        executeAction(charIDToTypeID("slct"), desc, DialogModes.NO ); 

    }catch(e){} 

};

///////////////////////

// THE MAIN BIT ///////

///////////////////////

var doc = app.activeDocument;

var slctdLyrs = getSelectedLayers();

function main(){

    var lyrA = slctdLyrs[0];

    var lyrB = slctdLyrs[1];

    var aID = slctdLyrs[0].id;

    var bID = slctdLyrs[1].id;

    var lyrABounds = visibleBounds(lyrA);

    var lyrBBounds = visibleBounds(lyrB);

    var posA = [ lyrABounds[0], lyrABounds[1] ]; //position of top left corner

    var posB = [ lyrBBounds[0], lyrBBounds[1] ]; //position of top left corner

    var deltaX = difference(posA[0], posB[0]); //difference in x axis

    var deltaY = difference(posA[1], posB[1]);//difference in y axis

    if (deltaX[1] == false) { // translates layers in x axis

        lyrA.translate((deltaX[0] * -1), 0);

        lyrB.translate(deltaX[0], 0);

    } else {

        lyrA.translate(deltaX[0], 0);

        lyrB.translate((deltaX[0] * -1), 0);

    }

    if (deltaY[1] == false) { // translates layers in y axis

        lyrA.translate(0, (deltaY[0] * -1));

        lyrB.translate(0, deltaY[0]);

    } else {

        lyrA.translate(0, deltaY[0]);

        lyrB.translate(0, (deltaY[0] * -1));

    }

    //reselect 1st layer

    selectLayerById(aID, false);

    //reselect 2nd layer

    selectLayerById(bID, true);

}

///////////////////////

// EXECUTE IT /////////

///////////////////////

if (slctdLyrs.length == 2) {

    try {

        doc.suspendHistory("Swap Layers", "main()" );

    }

    catch (e){

        alert(e);

    }

} else {

    alert("Ouch!\nSelect two layers to swap their positions!");

}

///////////////////////

// REVERT /////////////

///////////////////////

//restore preferences

app.preferences.rulerUnits = startRulerUnits;

app.preferences.typeUnits = startTypeUnits;

app.displayDialogs = startDisplayDialogs;

[SuperMerlin]

[Artlayer].id does not exist with CS6 and early versions of CC, you will need to check your versions.

For CS6 and CC you should be able to use...

function getLayerID(){
var ref = new ActionReference();
ref.putEnumerated( charIDToTypeID('Lyr '),charIDToTypeID('Ordn'),charIDToTypeID('Trgt') ); 
return executeActionGet(ref).getInteger(stringIDToTypeID( "layerID" ));
};