index.js

var Client = require('./upnp_client.js')

var client = new Client('http://192.168.1.6:49152/description.xml');
console.log(client);

// Get the device description
client.getDeviceDescription(function(err, description) {
  if(err) throw err;
  console.log("starting device description module")
  console.log(description);
  console.log("ending device description module")
});

client.callAction('AVTransport', 'GetMediaInfo', { InstanceID: 0 }, function(err, result) {
  if(err) throw err;
  console.log(result); // => { NrTracks: '1', MediaDuration: ... }
});

upnp_client.js

require("tabris-js-node");
// var util = require("util");
var et = require('elementtree'); // remove the utils

function DeviceClient(url) {
  this.url = url;
  this.deviceDescription = null;
  this.serviceDescriptions = {};
  this.server = null;
  this.listening = false;
  this.subscriptions = {};
}


DeviceClient.prototype.getDeviceDescription = function(callback) {
	var self = this;

	// Use cache if available
	if(this.deviceDescription) {
		process.nextTick(function() {
		  callback(null, self.deviceDescription);
		});
		return;
	}
	// console.log("this.url "+this.url)
	// console.log("self.url "+self.url)
	fetch(this.url)
	    .then(response => response.text())
	    .then((bodyText) => {
	    	var desc = parseDeviceDescription(bodyText, self.url);
	    	self.deviceDescription = desc // Store in cache for next call
	    	callback(null, desc);  // returns the result
	  }).catch((err) => {
	        console.log("OKAY.THERE IS AN ERROR");
	        console.log(err);
	});

};

function parseDeviceDescription(xml, url) {

	var doc = et.parse(xml);

	var desc = extractFields(doc.find('./device'), [
	    'deviceType', 
	    'friendlyName', 
	    'manufacturer', 
	    'manufacturerURL', 
	    'modelName', 
	    'modelNumber',
	    'modelDescription',
	    'UDN'
	]);

	var nodes = doc.findall('./device/serviceList/service');
	desc.services = {};
	nodes.forEach(function(service) {
	    var tmp = extractFields(service, [
	      'serviceType',
	      'serviceId',
	      'SCPDURL',
	      'controlURL',
	      'eventSubURL'
	    ]);

	    var id = tmp.serviceId;
	    delete tmp.serviceId;
	    desc.services[id] = tmp;
	});

	// Make URLs absolute
	var baseUrl = extractBaseUrl(url);

	// Reformat URLs from '/ctl/service' to 'http://host:port/ctl/service'
	// It was fucking there job to give it pretty
	Object.keys(desc.services).forEach(function(id) {
    	var service = desc.services[id];
    	service.SCPDURL = buildAbsoluteUrl(baseUrl, service.SCPDURL);
    	service.controlURL = buildAbsoluteUrl(baseUrl, service.controlURL);
    	service.eventSubURL = buildAbsoluteUrl(baseUrl, service.eventSubURL);
	});

	return desc;

};


function extractFields(node, fields) {
  var data = {};
  fields.forEach(function(field) {
    var value = node.findtext('./' + field);
    if(typeof value !== 'undefined') {
      data[field] = value;
    }
  });
  return data;
}

function buildAbsoluteUrl(base, url) {
  if(url === '') return '';
  if(url.substring(0, 4) === 'http') return url;
  if(url[0] === '/') {
    var root = base.split('/').slice(0, 3).join('/'); // http://host:port
    return root + url;
  } else {
    return base + '/' + url;
  }
}


function extractBaseUrl(url) {
  return url.split('/').slice(0, -1).join('/'); // removes the last slash
}




DeviceClient.prototype.getServiceDescription = function(serviceId, callback) {
  var self = this;

  serviceId = resolveService(serviceId);

  this.getDeviceDescription(function(err, desc) {
    if(err) return callback(err);

    var service = desc.services[serviceId];

    if(!service) { // check if they are out of there mind
      var err = new Error('Service ' + serviceId + ' not provided by device');
      err.code = 'ENOSERVICE';
      return callback(err);
    }

    // Use cache if available
    if(self.serviceDescriptions[serviceId]) {
      return callback(null, self.serviceDescriptions[serviceId]);
    }

	fetch(service.SCPDURL)
	    .then(response => response.text())
	    .then((bodyText) => {
	    	var desc = parseServiceDescription(bodyText);
	    	self.serviceDescriptions[serviceId] = desc; // Store in cache for next call
	    	callback(null, desc);  // returns the result
	  }).catch((err) => {
	        console.log("OKAY.THERE IS AN ERROR");
	        console.log(err);
	}); // end fetch

  }); // end getDeviceDescrioption

};

function resolveService(serviceId) {
  return (serviceId.indexOf(':') === -1) 
    ? 'urn:upnp-org:serviceId:' + serviceId 
    : serviceId;  
}


function parseServiceDescription(xml) {
  var doc = et.parse(xml);
  var desc = {};

  desc.actions = {};
  var nodes = doc.findall('./actionList/action');
  nodes.forEach(function(action) {
    var name = action.findtext('./name');
    var inputs = [];
    var outputs = [];

    var nodes = action.findall('./argumentList/argument');
    nodes.forEach(function(argument) {
      var arg = extractFields(argument, [
        'name',
        'direction',
        'relatedStateVariable'
      ]);

      var direction = arg.direction;
      delete arg.direction;

      if(direction === 'in') inputs.push(arg);
      else outputs.push(arg);
    });

    desc.actions[name] = {
      inputs: inputs,
      outputs: outputs
    };
  });

  desc.stateVariables = {};
  var nodes = doc.findall('./serviceStateTable/stateVariable');
  nodes.forEach(function(stateVariable) {
    var name = stateVariable.findtext('./name');

    var nodes = stateVariable.findall('./allowedValueList/allowedValue');
    var allowedValues = nodes.map(function(allowedValue) {
      return allowedValue.text;
    });

    desc.stateVariables[name] = {
      dataType: stateVariable.findtext('./dataType'),
      sendEvents: stateVariable.get('sendEvents'),
      allowedValues: allowedValues,
      defaultValue: stateVariable.findtext('./defaultValue')
    };
  });

  return desc;
}





DeviceClient.prototype.callAction = function(serviceId, actionName, params, callback) {
  var self = this;
  serviceId = resolveService(serviceId);

	this.getServiceDescription(serviceId, function(err, desc) {
	    if(err) return callback(err);

	    if(!desc.actions[actionName]) {
	      var err = new Error('Action ' + actionName + ' not implemented by service');
	      err.code = 'ENOACTION';
	      return callback(err);
	    }

		var service = self.deviceDescription.services[serviceId];

		var UA = "UPnP/1.0, UPNPClient/0.0.1";
	    var soapAction = service.serviceType + "#" + actionName;

	    var body = "<u:" + actionName + " xmlns:u=\"" + service.serviceType + "\">";
	    for(var x in params) {
	        body += "<" + x + ">" + params[x] + "</" + x + ">";
	    }
	    body += "</u:" + actionName + ">";

		var payload = `<?xml version="1.0"?>
		<s:Envelope xmlns:s="http://schemas.xmlsoap.org/soap/envelope/" s:encodingStyle="http://schemas.xmlsoap.org/soap/encoding/">
		 <s:Body>` + 
		 	body +	  
		 `</s:Body>
		</s:Envelope>`;

		var xmlHTTP = new tabris.XMLHttpRequest();

		xmlHTTP.open('POST', service.controlURL, true);

		xmlHTTP.setRequestHeader('SOAPAction', '"' + soapAction + '"');
		xmlHTTP.setRequestHeader('Content-Type', 'text/xml; charset="utf-8"');
		xmlHTTP.setRequestHeader('User-Agent', UA);
		xmlHTTP.onreadystatechange = function() {
		  if(xmlHTTP.readyState === xmlHTTP.DONE) {
		  		var doc = et.parse(xmlHTTP.responseText);
		  		// Extract response outputs
		        var serviceDesc = self.serviceDescriptions[serviceId];
		        var actionDesc = serviceDesc.actions[actionName];
		        var outputs = actionDesc.outputs.map(function(desc) {
		          return desc.name;
		        });

		        var result = {};
		        outputs.forEach(function(name) {
		          result[name] = doc.findtext('.//' + name);
				});

				callback(null, result)

		        // console.log("THIS IS MINE ----"+xmlHTTP.responseText)
		    } else {
		        console.log("not OK: " + xmlHTTP.status + ": "+JSON.stringify(xmlHTTP))

		  }
		}; // end xmlHTTP

		xmlHTTP.send(payload);

	}); // end this.getServiceDescription
};

module.exports = DeviceClient;