Javascript function executes twice, Meteor js -

this simple script horizontal fortune roulette, created using slick slider. problem: function rollout() executed twice (and helpers too) because template rendered twice. i'm using iron:router routing, code:

router.configure({   loadingtemplate: "loading",   layouttemplate: "layout" }); router.map(function() {   this.route("hello", {     path: "/",     waiton: function() {       return meteor.subscribe("games");     }   }); }); 

hello.js:

session.setdefault('currentslide', 0);     template.hello.events({       'click .create': function(e) {         e.preventdefault();         var ins = {           gamestarttime: new date(),           finished: false         }         games.insert({           gamestarttime: new date(),           finished: "false"         });         session.set("gamestatus", "waiting");       }     })     template.hello.helpers({       currentslide: function() {         var value = session.get('currentslide');         if (value === 25) {           return 0;         }         return value;       },       games: function() {         var game = games.find();         return game;       },       gamehandler: function() {         var game = games.findone();         var gamestatus = session.get("gamestatus");         if (game && game.finished === "false" && gamestatus === "waiting") {           games.update({_id: game._id}, {             $set: {running: true}           });          } else if (gamestatus === "finished") {            meteor.call('updategame', game._id); //remove item collection after game over; error here: typeerror: cannot read property '_id' of undefined;            console.log('game finished');         }         if (game && game.running === true) {           //set session variable , launch roulette           session.set("gamestatus", "running");           rollout(game._id);         }       }     });     var rollout = function(gameid) {       session.set("gamestatus", "running");       //make div's visible. have display:none default.       document.getelementbyid("roulette").style.display = "block";       document.getelementbyid("result").style.display = "block";       document.getelementbyid("wrapper").style.display = "none";       var speed = 500; //default slider speed       session.setdefault('speed', speed);       var r = $('#roulette').slick({         centermode: true,         slidestoshow: 7,         slidestoscroll: 1,         autoplay: true,         autoplayspeed: 0,         speed: speed,         draggable: false,         pauseonhover: false,         cssease:'linear'       });       var maximum = 14;       var minimum = 0;       var randomnumber = math.floor(math.random() * (maximum - minimum + 1)) + minimum;       var winresult = randomnumber;       var speed = 80;       var currentslide = session.get('currentslide');       function roll(callback) {         session.set('currentslide', r.slickcurrentslide());         if (speed < 800) {           speed += 20;           r.slicksetoption("speed", speed, false);           settimeout(function() {             roll(callback);           }, 500);         } else if (speed >= 600 && speed < 1300) {           speed += 40;           r.slicksetoption("speed", speed, false);           settimeout(function() {             roll(callback);           }, 300);         } else if (speed >= 1300 && speed < 20000) {           settimeout(function() {             speed += 3;             r.slicksetoption('speed', speed, false);             if (session.get('currentslide') === winresult) {               r.slickpause();               settimeout(function() {                 //hide roulette div's                 document.getelementbyid("roulette").style.display = "none";                 document.getelementbyid("result").style.display = "none";                 document.getelementbyid("wrapper").style.display = "block";                 r.unslick();                  session.set('currentslide', 0);                 session.set("gamestatus", "finished");                 callback(true);                 return               }, 10000);             } else {               roll(callback);             }           }, 30)         }  else {           callback(true);         }       }       roll(function(callback) {         meteor.call('updategame', gameid); //remove item collection         session.set("gamestatus", "finished");       });     } 

in template i'm using spinner sacha:spin package , working fine.

the gamehandler function should not in template helpers, meant supply information template. instead, logic needs moved autorun function. autorun statement re-run anytime reactive datasource within changes.

ex:

template.hello.oncreated(function() {     this.autorun(function() {         var game = games.findone();         var gamestatus = session.get("gamestatus");         // ...etc     }); }