Problems using data converter with RadAutoCompleteTextView


I have been trying to use data converter with RadAutoCompleteTextView but so far no luck

Here is the viewModel where Uppercase is the converter

const observableModule = require("data/observable");
var ObservableArrayModule = require("data/observable-array");

var  TokenModel = require("nativescript-pro-ui/autocomplete").TokenModel;
function SearchModalViewModel( context ) {
    var Uppercase = {
        toView: function(value) {
            return value.toUpperCase();
    var viewModel = observableModule.fromObject({
        dataItems: new ObservableArrayModule.ObservableArray(),
        testButton: "button test",
        Uppercase : Uppercase
    for (var i = 0; i < persons.length; i++) {
        viewModel.dataItems.push(new TokenModel(persons[i].customer_name, undefined));
    return viewModel;
module.exports = SearchModalViewModel;

and here is the XML

<GridLayout rows="60, auto" columns="*" >
        <Button row="0" col="0" text="{{test | Uppercase }}"  />
        <au:RadAutoCompleteTextView row="1" col="0" items="{{ dataItems }}"> 
            <au:SuggestionView suggestionViewHeight="300">
                <au:SuggestionView.suggestionItemTemplate >
                    <StackLayout orientation="vertical">
                        <Label text="{{ text | Uppercase }}"></Label>

Here converter works fine for the button; however, for the search results I get the following error

JS: Binding: Run-time error occured in file: undefined at line: undefined and column: undefined
JS: Cannot find function or filter: Uppercase

Date converter in a RadListView

I even tried to set the converter in the application resources in app.js like this

var Uppercase = {
    toView: function(value) {
        console.log('value: ' , value);
        return value.toUpperCase();
var appResources = application.getResources();
appResources.Uppercase = Uppercase;

It works everywhere except with RadAutoCompleteTextView