TVML / tvOS Detect end of scroll

I have collection list and shelf. I can download only 10 items. When user scrolled to end, I should make new request. But i dont how detect end of scroll in xml or in js

I have discovered sample codes from Apple and found one intersting event. It calls "needsmore".

//A DocumentController subclass that handles pagination for multiple shelfs
class ShelfDocumentController extends DocumentController {

setupDocument(document) {
    super.setupDocument(document)

    let shelfs = document.getElementsByTagName("shelf")
    if (!shelfs || shelfs.lenth == 0) { return }

    //enumerate all shelfs in the template
    for (let idx = 0; idx < shelfs.length; ++idx) {
        let shelf = shelfs.item(idx)
        shelf.page = 1

        //using the data url from the shelf's first section (there should only be one section per shelf)
        let sections = shelf.getElementsByTagName("section")
        if (!sections || sections.length == 0) { continue }

        let section = sections.item(0)
        let pageUrl = section.getAttribute("dataURL")

        //add the listener to the shelf
        shelf.addEventListener("needsmore", (event) => {
            //replace this code with your logic for getting new pages
            shelf.page = shelf.page + 1
            if (shelf.page > 10) { return }
            let nextPageUrl = pageUrl.replace("\.json", "_" + shelf.page + ".json")
            this.fetchNextPageAtURL(nextPageUrl, section);
        })
    }
}
}