Meteor Sessions

Anonymous Viewers Count

Router.onBeforeAction(function(){
    var postSlug = this.params.slug;
    var currentPost = Posts.findOne({slug: postSlug});
    
    var anonymousSession = "anonymousViewers_"+currentPost._id;
    var anonymousCount = Session.get(anonymousSession);

    if(anonymousCount){
        Session.set(anonymousSession, parseInt(anonymousCount) + 1);
    }else{
        Session.set(anonymousSession, 1);
    }

    this.next();
}, {
    only: ["post"]
});

When I add the lines 8-12 my application just hangs. I just can't understand what I'm doing wrong.

Router.onBeforeAction(function(){
    var postSlug = this.params.slug;
    var currentPost = Posts.findOne({slug: postSlug});

    var anonymousSession = "anonymousViewers_"+currentPost._id;
    var anonymousCount = Session.keys[anonymousSession]; // ** change here
    var sessionObject = {};

    if(anonymousCount){
        sessionObject[anonymousSession] = parseInt(anonymousCount) + 1
    }else{
        sessionObject[anonymousSession] = parseInt(anonymousCount) + 1
    }
    Session.set(sessionObject);

    this.next();
}, {
    only: ["post"]
});