[NODE] Javascript Promises using Q library simple examples

callback_weather.js

// Using callbacks to retrieve Weather Data
var RestClient = require('restler')

var getURL = function(city){
  return 'http://api.openweathermap.org/data/2.5/weather?q=' + city;
};

var dateOne = new Date();

RestClient.get(getURL('London')).on('complete', function(data1){
  RestClient.get(getURL('Sao Paulo')).on('complete', function(data2){
    console.log([data1.name, data2.name]);

    var dateTwo = new Date();
    console.log(dateTwo.getTime() - dateOne.getTime());
  });
});

promise_set_timeout_sum.js

var Q = require('q');

var sum = function() {
  var d = Q.defer();

  setTimeout(function() {
    d.resolve(1);
  }, 3000);
  return d.promise;
};

var second = function(first) {
  var d = Q.defer();

  setTimeout(function() {
    d.resolve(first + 2);
  }, 3000);
  return d.promise;
};

var end = function(result) { console.log(result) };

sum().then(second).done(end)

promise_simple_sum.js

var Q = require('q');

var sum = Q.fcall(function () {
  return 1;
});

var second = function(first){
  return first + 2;
}

var end = function(result) { console.log(result) };

sum.then(second).done(end)

promise_weather.js

// Using promises to retrieve Weather Data
var Q = require('q');
var RestClient = require('restler')

var getWeatherFromCity = function(city) {
  var d = Q.defer();

  var url = 'http://api.openweathermap.org/data/2.5/weather?q=' + city;

  RestClient.get(url).on('complete', function(data){
    d.resolve(data.name);
  });

  return d.promise;
};

var someFunc = function(data){
  var d = Q.defer();

  getWeatherFromCity('Sao Paulo').then(function(spData){
    d.resolve([data, spData])
  });

  return d.promise;
};

var doneFunc = function(data){
  console.log(data);

  var dateTwo = new Date();
  console.log(dateTwo.getTime() - dateOne.getTime());
};

var dateOne = new Date();

getWeatherFromCity('London').then(someFunc).done(doneFunc);