MultiSelectDialog with custom query method is showing empty rows

ERPNext Customize ERPNext
#1

Hi,
I tried to use MultiSelectDialog with custom query method as following code:
//Second Category
frappe.ui.form.on(“Item”, {
add_second_category: function(frm){
let query_args = {
//Backend method that get’s called and returns the Categories
query: “masar_oldtimer.custom.item.item.second_category_query”,
filters: {‘item_code’: frm.doc.item_code}
}
var s = new frappe.ui.form.MultiSelectDialog({
doctype: “Item Second Category”,
target: me.frm,
setters: {
first_category: “”,
second_category: “”
},
add_filters_group: 1,
columns: [“name”, “first_category”],
get_query() {
return query_args;
},
primary_action_label: “Get Category”,
action(selected_categories) {
frappe.call({
method: “masar_oldtimer.custom.item.item.insert_selected_second_category”,
args: {
selected_categories: selected_categories
},
callback: function(r) {
$.each(r.message, function(i, d) {
var row = frappe.model.add_child(cur_frm.doc, “Item Second Category Value”, “second_category”);
row.second_category = d.second_category;
refresh_field(“second_category”);
});
}
});
s.dialog.hide();
}
})
}
});

but i got the result as empty rows

image
image1600×900 113 KB

Any advice, please?

#2 
//Second Category
frappe.ui.form.on("Item", {
  add_second_category: function(frm){
let query_args = {
    //Backend method that get's called and returns the Categories
    query: "masar_oldtimer.custom.item.item.second_category_query",
    filters: {'item_code': frm.doc.item_code}
}
var s = new frappe.ui.form.MultiSelectDialog({
  doctype: "Item Second Category",
  target: me.frm,
  setters: {
    first_category: "",
    second_category: ""
  },
  add_filters_group: 1,
  columns: ["name", "first_category"],
  get_query() {
    return query_args;
  },
  primary_action_label: "Get Category",
  action(selected_categories) {
    frappe.call({
      method: "masar_oldtimer.custom.item.item.insert_selected_second_category",
      args: {
        selected_categories: selected_categories
      },
      callback: function(r) {
        $.each(r.message, function(i, d) {
          var row = frappe.model.add_child(cur_frm.doc, "Item Second Category Value", "second_category");
          row.second_category = d.second_category;
          refresh_field("second_category");
        });
      }
    });
    s.dialog.hide();
  }
})
	}
});

My code in better way