TVML listItemLockup click event - tvos

Question

I'm using the 'Compilation.xml' template from the TVMLCatalog
I'd like to add a button click event to a 'listItemLockup'
<listItemLockup>
<ordinal minLength="2" class="ordinalLayout">0</ordinal>
<title>Intro</title>
<subtitle>00</subtitle>
<decorationLabel>(3:42)</decorationLabel>
</listItemLockup>
I've tried adding:
App.onLaunch = function(options) {
var templateURL = 'http://localhost:8000/hello.tvml';
var doc = getDocument(templateURL);
//doc.addEventListener("select", function() { alert("CLICK!") }, false);
var listItemLockupElement = doc.getElementsByTagName("listItemLockup");
listItemLockupElement.addEventListener("select", function() { alert("CLICK!") }, false);
}
addEventListener
void addEventListener (in String type, in Object listener, in optional Object extraInfo)
Is "select" the correct type?
I've been using the following tutorials
http://jamesonquave.com/blog/developing-tvos-apps-for-apple-tv-with-swift/
http://jamesonquave.com/blog/developing-tvos-apps-for-apple-tv-part-2/
Update
I'm getting an error
ITML <Error>: doc.getElementsByTagName is not a function. (In 'doc.getElementsByTagName("listItemLockup")', 'doc.getElementsByTagName' is undefined) - http://localhost:8000/main.js - line:27:58
I tried adding this to the 'onLaunch'
var listItemLockupElements = doc.getElementsByTagName("listItemLockup");
for (var i = 0; i < listItemLockupElements.length; i++) {
//var ele = listItemLockupElements[i].firstChild.nodeValue;
listItemLockupElements[i].addEventListener("select", function() { alert("CLICK!") }, false);
}
I'll see about the error first
Cross Post: https://forums.developer.apple.com/thread/17859

Answer 1

More common example I have seen by Apple is to define a single overall listener like:
doc.addEventListener("select", Presenter.load.bind(Presenter));
In your xml, assign unique ids to elements, or give them ways to identify them.
For example, the beginning would be something like:
load: function(event) {
var self = this,
ele = event.target,
attr_id = ele.getAttribute("id"),
audioURL = ele.getAttribute("audioURL"),
videoURL = ele.getAttribute("videoURL")
And then you can do whatever you want with your item.
if(audioURL && (event.type === "select" || event.type === "play")) {
//
}
My advice would be to study the Presenter.js file more carefully for this pattern.
Edit:
Answering your "Update" related to doc.getElementsByTagName is not a function. "doc" does not actually exist, but the general pattern is to get it with
var doc = getActiveDocument();
I assumed you would know the above.
Does that fix it?

Answer 2

var listItemLockupElement = doc.getElementsByTagName("listItemLockup”);
In this case, the listItemLockupElement is a NodeList, not an element. You can either iterate through the list and add an event listener to each listItemLockup, or you could add the event listener to the containing element.

Answer 3

When addressing items in a NodeList, you use the item(i) method rather than the standard array access notation:
listItemLockupElements.item(i).addEventListener("select", function() { })
See: https://developer.mozilla.org/en-US/docs/Web/API/NodeList/item

Answer 4

Adding event listeners is straightforward if you're using atvjs framework.
ATV.Page.create({
name: 'mypage',
template: your_template_function,
data: your_data,
events: {
select: 'onSelect',
},
// method invoked in the scope of the current object and
// 'this' will be bound to the object at runtime
// so you can easily access methods and properties and even modify them at runtime
onSelect: function(e) {
let element = e.target;
let elementType = element.nodeName.toLowerCase();
if (elementType === 'listitemlockup') {
this.doSomething();
}
},
doSomething: function() {
// some awesome action
}
});
ATV.Navigation.navigate('mypage');
Disclaimer: I am the creator and maintainer of atvjs and as of writing this answer, it is the only JavaScript framework available for Apple TV development using TVML and TVJS. Hence I could provide references only from this framework. The answer should not be mistaken as a biased opinion.