User callbacks for the JavaScript PPS API

The JavaScript PPS API supports user-implemented callbacks that listen for PPS data and handle errors.

The datalistener() callback is used by the following methods:

• ppsService.read()
• ppsService.removeWatch()
• ppsService.watch()

The errorlistener() callback is used by the following methods:

• ppsService.close()
• ppsService.open()
• ppsService.read()
• ppsService.removeWatch()
• ppsService.watch()
• ppsService.write()
• ppsService.writeNativeData()