NEM-sdk: Read outgoing Transactions for a given Account (Scores stored as Mosaic Transfer Transactions)

read_scores.js

console.log("Hello, NEMber");

// Configure a Blockchain endpoint and include SDK
var NEM_HOST = "http://bob.nem.ninja"; // bob is Testnet!
var NEM_PORT = 7890;
var nem  = require("nem-sdk").default;
var node = nem.model.objects.create("endpoint")(NEM_HOST, NEM_PORT);

// Read Outgoing Transactions for the given game/application Account (pacnem-business)
nem.com.requests.account.outgoingTransactions(node, "TCTIMURL5LPKNJYF3OB3ACQVAXO3GK5IU2BJMPSU")
     .then(function(response)
     {
          var scores = {};

          // each row in `response` array is a Transaction on the NEM Blockchain.
          for (var i in response) {
               var transaction  = response[i];
               var trxMeta      = transaction.meta;
               var trxContent   = transaction.transaction;
               var trxRecipient = trxContent.recipient;

               if (! trxContent.mosaics || !trxContent.mosaics.length)
                    continue; // not interested in this transaction

               for (var j in trxContent.mosaics) {
                    var mosaic = trxContent.mosaics[j];
                    if ("evias.pacnem" != mosaic.mosaicId.namespaceId || "cheese" != mosaic.mosaicId.name)
                         continue; // we want only evias.pacnem:cheese

                    var gameScore = mosaic.quantity;

                    var score = {
                         "timeStamp": trxContent.timeStamp,
                         "score": gameScore,
                         "player": trxRecipient
                    };

                    // create score entry in case no one had this score before
                    if (! scores.hasOwnProperty(gameScore))
                         scores[gameScore] = [];

                    // append the built high score object to the array of high scores
                    // with the same `gameScore`.
                    scores[gameScore].push(score);
               }
          }

          // scores are not sorted yet, we must sort in descending order by score.
          var distinctScores = Object.keys(scores);
          distinctScores.sort().reverse();

          // Distinct scores might have multiple entries (more than one Player can have one score)
          // Scores are ordered now, we only need to dedup the scores to build a final history (Best Player on Top)
          var orderedHighScores = [];
          for (var i in distinctScores) {
               var gameScore = distinctScores[i];
               var scoreEntries = scores[gameScore];

               // There might be multiple Players with the same High Score.
               for (var j in scoreEntries)
                    orderedHighScores.push(scoreEntries[j]);
          }

          // save this somewhere.. you don't want to query the blockchain every time for this.
          var allTimeHighScore = orderedHighScores.length ? orderedHighScores[0] : 0;

          // DONE.
          // Print our High Scores to the Console
          console.log("PacNEM Hall of Fame:");
          console.log("--------------------");
          console.log("");

          for (var i in orderedHighScores) {
               var highScore = orderedHighScores[i];
               var position  = "  (" * (i+1) + ")";
               console.log(position + " Player " + highScore.player + " with a Score of: " + highScore.score);
          }
     },
     function(error) { // General Error OR wrong Network for Address OR No Mosaics available });