How to detect menu button press in TVOS app using TVJS - tvos

Question

I need to know when a document(screen) is popped off the stack in an Apple tvOS app. I thought detecting the Menu button press would be the simplest way, but I'm using TVJS and have not been able to figure out how to write the event handler.
Please help me write an event handler that will fire on document removal, menu button press or offer an alternative solution.

Answer 1

Subscribe to the event unload - it's triggered whenever a page disappears after being popped from the stack:
doc.addEventListener("unload", Presenter.onUnload.bind(Presenter));
[...]
onUnload: function(event) {
console.log("onUnload");
},

Answer 2

There is such thing of a handler for onDocumentRemoval or similar. What you can do, instead, is create a global select handler:
doc.addEventListener("select", self.doThing.bind(self));
And then check if the fired event comes from one of the buttons used to remove an element of the stack (let's suppose those buttons have a class named delete:
doThing: function(event){
var element = event.target;
if (element.getAttribute("class").contains("delete")){
//enter code here
}
EDIT 1:
I found the possible events the TVMLKit handles (I know it is in Swift/Objective-C, but the events are the same):
TVElementTypePlay
A play event has been dispatched.
TVElementTypeSelect
A select event has been dispatched.
TVElementTypeHoldSelect
A hold event has been dispatched.
TVElementTypeHighlight
A highlight event has been dispatched.
TVElementTypeChange
A change event has been dispatched.
Those events are only attachable to a template as far as I could test. I guessed the change event would be perfect if I could attach it to the navigationDocument to listen for changes, but those two options won't work and both fire errors:
Attached to the global:
navigationDocument.addEventListener("change", function(event){console.log(event)});
Attached to the documents array:
navigationDocument.documents.addEventListener("change", function(event){console.log(event)});
There is no built-in method for those above to listen for any change. The event, though, will work on a template listening to internal changes. But it won't fire when the template is pushed to or popped from the stack.
I am guessing you will need to re-design your app in order to achieve what you are looking for.