Wrapping Asynchronous NPM in Meteor - meteor

Question

I am using meteor-npm to use NPM in my Meteor app. I have successfully added serialport and xbee-api. I can read xbee frames using console.log, but I cannot pass the frame to a Meteor method. The code below gives me an error about NPM functions and using bindEnvironment. I'm sure that it has something to do with Meteor running synchronous vs xbee-api running asynchronous. I'm fairly familiar with Meteor, but not with using it with NPM. I believe the answer may be in https://github.com/arunoda/meteor-npm. I don't really need a callback, as I just want the frame data passed to a method and I will handle it from there. Can anyone shed some light on this for me? Thanks in advance.
// Load serialport and xbee-api
var serialport = Meteor.require('serialport');
var SerialPort = serialport.SerialPort;
var xbee_api = Meteor.require('xbee-api');
// Load constants to help with remembering hex codes for xbees
var C = xbee_api.constants;
// Create xbee
var xbee = new xbee_api.XBeeAPI({
api_mode: 2
});
// Create serial port
var serialPort = new SerialPort('/dev/tty.usbserial-A901L66E', {
baudrate: 9600,
// Provided with xbee-api. Could use com.parsers.raw and feed that to xbee-api
parser: xbee.rawParser()
});
// Setup action to take when serial port is connected
serialPort.on('open',function() {
console.log('Port open');
});
// Setup action to take when xbee packet is received
// frame_object is emitted by the xbee.rawParser every time a complete xbee packets is received
xbee.on('frame_object', function(frame) {
//Send frame to Meteor method
Meteor.call('xbeeIncoming', frame);
//console.log('>>',frame);
});
Meteor method definition:
Meteor.methods({
xbeeIncoming: function xbeeIncoming(frame) {
console.log('xbeeData');
//var xbeeSenderAddr = frame.addr
}
});

Answer 1

Why are you using a method to do this. If both of them are on the server side you could use a private method instead i.e
xbeeIncoming = function(frame) {
console.log('xbeeData');
}
instead of Meteor.call('xbeeIncoming', frame); you could use xbeeIncoming(frame);
You will need to wrap the callback from xbee in a bindEnvironment (provide it can be serialized into JSON/EJSON):
var onFrame = function(frame ) {
Meteor.call('xbeeIncoming', frame);
//console.log('>>',frame);
}
xbee.on('frame_object', Meteor.bindEnvironment(onFrame));
From within this, Meteor.call should work as expected