Getting Selected Layer or group layers array using javascript (Photoshop CS4)

Question

K basically I need to write a photoshop script that iterates through the selected layers and retrieve some information about them.

if I can get an array of the selected layers I will be fine, I know how to do the rest, but getting that array is been a headache on its own.

I know the document holds something like "activeLayers" but I get lost how to deal with levels and sublevel layers.

All the layers are in a group, so if its easier, if I can get every layer in a group that would be great too :D

Thanks for any tips on this.

Answer 1

Bravo's code works except it fails with an error when no layers are selected, so I tweaked it to remove the error and simply return an empty array:

function getSelectedLayers(){
  var resultLayers=new Array();
  try{
    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.NO );
    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 );
  } catch (err) { }
  return resultLayers;
}   
$.writeln(getSelectedLayers());`

Simply wrapping the code in a try/catch block didnt work, so I also changed:

executeAction( idGrp, descGrp, DialogModes.ALL );

to

executeAction( idGrp, descGrp, DialogModes.NO );

and that made the runtime error go away.

Answer 2

This will get you the selected layers

 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;
    }   
    var layers = getSelectedLayers();

Source: https://github.com/kynd/photoshopScripts/blob/master/Rename%20Selected%20Layers/Rename%20Selected%20Layers.jsx

Answer 3

You'll need to check out the 'ArtLayers' and 'LayerSets' objects. The following snippet will get all the layers in the first group within a document:

var lyrs = app.activeDocument.layerSets[0].artLayers;

But since each of your groups can contain other groups, you may have to recursively loop through all of them to get all your layers depending on your use case.

I highly recommend checking out the xtools library. It has a nice function 'Stdlib.getLayersList' that will allow you to get the all the layers recursively from nested groups (plus a whole lot of other great stuff). Get the library here.