follow_mercadobitcoin.algo

/*
 -----BEGIN ALGO DEFINITION-----
 {
 "id": "bitstamp",
 "description": "Notifies the user when there is a new best bid/ask at MercadoBitcoin",
 "params": [],
 "creator": "blinktrade.FollowMercadoBitcoin.create",
 "destructor": "blinktrade.FollowMercadoBitcoin.destroy",
 "permissions": ["notification", "balance", "execution_report", "new_order_limited", "cancel_order"]
 }
 -----END ALGO DEFINITION-----
 -----BEGIN ALGO-----
 /**/


/**
 * Namespace.
 */
var blinktrade = {};

/**
 * Workaround using yahoo yql api to make cross domain requests
 * @param {string} url
 * @param {function(*)} fn
 * @param {Object} selfObj
 */
function crossDomainRequest( url, fn, selfObj) {
  var callback_function_name = 'yqlCallback' + parseInt(Math.random() * 1000000, 10);
  self[callback_function_name] = function( yqlResult ) {
    goog.bind(fn,selfObj, yqlResult.query.results)();
  };

  var yql = 'select * from json where url="' + url + '"';
  var uri = 'https://query.yahooapis.com/v1/public/yql?q=' +
      encodeURIComponent(yql) + '&format=json&callback=' + callback_function_name ;
  importScripts(uri);
}

/**
 * @param {Object} application
 * @param {string} symbol
 * @constructor
 */
blinktrade.FollowMercadoBitcoin = function(application, symbol){
  this.application_ = application;
  this.symbol_ = symbol;
  global_instance = this;

};

/**
 * @type {number}
 */
blinktrade.FollowMercadoBitcoin.prototype.last_best_bid_;

/**
 * @type {number}
 */
blinktrade.FollowMercadoBitcoin.prototype.last_best_ask_;

/**
 * @param {Application} application
 * @param {string} symbol
 * @return {blinktrade.FollowMercadoBitcoin}
 */
blinktrade.FollowMercadoBitcoin.create = function(application,symbol) {
  return new blinktrade.FollowMercadoBitcoin(application,symbol);
};

/**
 * @param {Object} params
 */
blinktrade.FollowMercadoBitcoin.prototype.start = function(params) {
  console.log('blinktrade.FollowMercadoBitcoin.prototype.start');
  this.timer_ = setInterval(goog.bind(crossDomainRequest,
                                      this,
                                      'https://www.mercadobitcoin.net/api/v2/ticker/',
                                      this.onMBCallBack_,
                                      this ), 6000 ); // every 60 seconds
};


blinktrade.FollowMercadoBitcoin.prototype.stop = function() {
  clearInterval(this.timer_);
};

/**
 * @param {Object.<string,*>} params
 */
blinktrade.FollowMercadoBitcoin.prototype.onUpdateParams = function(params) {};



blinktrade.FollowMercadoBitcoin.prototype.onMBCallBack_ = function(ticker){
  var best_bid = parseFloat(ticker['ticker']['buy']);
  var best_ask = parseFloat(ticker['ticker']['sell']);

  if (this.last_best_bid_ !=  best_bid) {
    this.last_best_bid_ = best_bid;
    this.application_.showNotification('MercadoBitcoin', 'The new best bid is ' + best_bid, 'success' );
  }

  if ( this.last_best_ask_ !=  best_ask ) {
    this.last_best_ask_ = best_ask;
    this.application_.showNotification('MercadoBitcoin', 'The new best ask is ' + best_ask, 'info' );
  }
};

//-----END ALGO-----