Hi @shiv19, thanks for a great workshop!
I'm trying using the ObservableArray and replacing it the "right" way by your example from rlv-tips.
However if you add [groupingFunction] to the RadListView it fails when you replace the array on Android with the following error:

ERROR Error: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String java.lang.Object.toString()' on a null object reference

It seems that after you replace the array using the replaceArray(), the grouping function gets undefined items as arguments. Do you have any suggestion how to solve this, or am I doing something totally wrong?

To reproduce the issue you can change the original array, and corresponding push (rlv-tips.component.ts):

private _origArray = [
{
title: "Row 1",
section: "section 1"
},
{
title: "Row 2",
section: "section 2"
},
{
title: "Row 3",
section: "section 3"
}
];

newArray.push({
title: "Row 4",
section: "section 4"
});

Add following grouping function:

getSectionName(item) {
return item.section;
}

Add the grouping function to the RadListView (rlv-tips.component.html)

<RadListView #lv row="1" [items]="source" [groupingFunction]="getSectionName">