I suppose it all depends whether you're trying to do this as a custom thing or whether you are trying to stick to being SCORM conformant. If you're doing this in a custom way, then this is the code you might add to Adapt:
Adapt.contentObjects.on('change:_isComplete', function (contentObject) {
console.log('page "' + contentObject.get('_id') + ' - ' + contentObject.get('title') + '" completed!');
// send data to LMS about this event
});
If you wanted to do it whilst sticking within the bounds of SCORM then you'd want to use something like cmi.objectives
- but unfortunately Adapt doesn't have any support for that yet as it crops up so rarely as a requirement. There is a PR for adding support for it here but I think it needs a fair bit of work as it feels overly complicated to use as it is.