Copy All Layers From Template Document

Please give the following script a try. I'm only a scripting beginner, so the code is ugly, but it works. All of the source layers from the template layer file will then be added to the destination file. This script is based upon the principles mentioned in my previous posts.

All you need to do is replace the filepath & filename '~/Desktop/Layer_Template.psd' on line 28 to match your template layer file's location.

This script can be recorded into an action and can then be batch processed via the Image Processor or Image Processor Pro scripts. No manual user intervention is required with this script, it is all automated.

Additional code could be added to this script to perform the batch processing and saving to make the code self-contained rather than relying on the IP or IPP scripts.

#target Photoshop 
// Copy All Layers From Template Document
// https://forums.adobe.com/message/11069602
displayDialogs = DialogModes.NO  
// Create a target layer for smart object  
// app.activeDocument.artLayers.add();  
// app.activeDocument.activeLayer.name = 'smartObject_Target';  
app.activeDocument.artLayers.add().name = 'smartObject_Target';  
  
// Place the Layer_Template file as an embedded smart object layer  
placeEvent();  
function placeEvent() {  
  var c2t = function (s) {  
  return app.charIDToTypeID(s);  
  };  
  
  var s2t = function (s) {  
  return app.stringIDToTypeID(s);  
  };  
  
  var descriptor = new ActionDescriptor();  
  var descriptor2 = new ActionDescriptor();  
  
  descriptor.putInteger(s2t("ID"), 13);  
  descriptor.putPath(c2t("null"), new File('~/Desktop/Layer_Template.psd')); // Layer_Template document file path  
  descriptor.putEnumerated(s2t("freeTransformCenterState"), s2t("quadCenterState"), s2t("QCSAverage"));  
  descriptor2.putUnitDouble(s2t("horizontal"), s2t("pixelsUnit"), 0.000000);  
  descriptor2.putUnitDouble(s2t("vertical"), s2t("pixelsUnit"), 0.000000);  
  descriptor.putObject(s2t("offset"), s2t("offset"), descriptor2);  
  executeAction(s2t("placeEvent"), descriptor, DialogModes.NO);  
}  
  
// Change the smart object layer name  
app.activeDocument.activeLayer.name = 'smartObject_Target';  
// Name the active doc in preparation for targeting the smart object layers
var targetDoc = app.activeDocument;
  
// Edit the smart object layer contents  
app.runMenuItem(stringIDToTypeID('placedLayerEditContents'));  
  
// Expand all layer sets  
// https://forums.adobe.com/message/5764024#5764024  
function openAllLayerSets(parent) {  
    for (var setIndex = 0; setIndex < parent.layerSets.length; setIndex++) {  
        app.activeDocument.activeLayer = parent.layerSets[setIndex].layers[0];  
        openAllLayerSets(parent.layerSets[setIndex]);  
    }  
};  
openAllLayerSets(app.activeDocument);  
  
// Select all layers and layer groups/sets!  
// https://feedback.photoshop.com/photoshop_family/topics/i-cant-record-sellect-all-layers-in-script-listener-and-in-actions  
selectAllLayers();  
function selectAllLayers() {  
    var c2t = function(s) {  
        return app.charIDToTypeID(s);  
    };  
  
    var s2t = function(s) {  
        return app.stringIDToTypeID(s);  
    };  
  
    var descriptor = new ActionDescriptor();  
    var descriptor2 = new ActionDescriptor();  
    var reference = new ActionReference();  
    var reference2 = new ActionReference();  
  
    reference2.putEnumerated(s2t("layer"), s2t("ordinal"), s2t("targetEnum"));  
    descriptor.putReference(c2t("null"), reference2);  
    executeAction(s2t("selectAllLayers"), descriptor, DialogModes.NO);  
    reference.putProperty(s2t("layer"), s2t("background"));  
    descriptor2.putReference(c2t("null"), reference);  
    descriptor2.putEnumerated(s2t("selectionModifier"), s2t("selectionModifierType"), s2t("addToSelection"));  
    descriptor2.putBoolean(s2t("makeVisible"), false);  
    try {  
        executeAction(s2t("select"), descriptor2, DialogModes.NO);  
    } catch (e) {}  
}  
  
// Duplicate the edited smart object layers to the original file  
app.activeDocument.activeLayer.duplicate(targetDoc)  
  
// Close the edited smart object layer document without saving changes  
app.activeDocument.close(SaveOptions.DONOTSAVECHANGES);  
  
// Remove the smart object layer as it was only a means to an end  
app.activeDocument.layers.getByName('smartObject_Target').remove();

One option in the short term, you can manually or via an action select all required layers in the source file, then use the Layer > Duplicate Layers command to move them to your destination file.

This general approach can be scripted, with various methods of selecting all layers, as it can become trickier once layers, layer sets, background image layers etc. come into play in different layer stack orders:

https://forums.adobe.com/thread/2585105

https://feedback.photoshop.com/photoshop_family/topics/i-cant-record-sellect-all-layers-in-script-listener-and-in-actions

Or perhaps an action or script could place the template layer file as a smart object, then move the layers from the smart object to the destination file.

Or possibly a folder of files as well. (Sorry for the add)