@karpiyon, this is not really related to original topic and IMO should be as a separate one, but here’s how you should do it… You should select first layer as usual and then each consecutive descriptor must have:
"selectionModifier": {"_enum": "selectionModifierType", "_value": "addToSelection"}
Full function to get descriptors:
const getSelectIdsActions = function (ids) {
return [
{
"_obj": "select",
"_target": [{"_ref": "layer", "_id": parseInt(ids[0])}],
"makeVisible": false
},
...ids.slice(1).map(id => (
{
"_obj": "select",
"_target": [{"_ref": "layer", "_id": parseInt(id)}],
"makeVisible": false,
"selectionModifier": {"_enum": "selectionModifierType", "_value": "addToSelection"}
}
))
];
};