Vulcan/server/vote.js

// TODO: should the baseScore be stored, and updated at vote time?

// This interface should change and become more OO, this'll do for now
var Scoring = {
  // re-run the scoring algorithm on a single object
  updateObject: function(object) {
    
    // just count the number of votes for now
    var baseScore = object.votes;

    // now multiply by 'age' exponentiated
    // FIXME: timezones <-- set by server or is getTime() ok?
    var ageInHours = (new Date().getTime() - object.submitted) / (60 * 60 * 1000);
    
    // object.score = baseScore * Math.pow(ageInHours + 2, -0.1375);

    // debug: just add 1 to the score for each new vote
    object.score = object.score+1;
  },
  
  // rerun all the scoring
  updateScores: function() {
    Posts.find().forEach(function(post) {
      Scoring.updateObject(post);
      Posts.update(post._id, {$set: {score: post.score}});
    });
  }
}




Meteor.methods({
  voteForPost: function(post){
    var userId = this.userId();
    if(!userId) return false;
    
    // atomically update the post's votes
    var query = {_id: post._id, voters: {$ne: userId}};
    var update = {$push: {voters: userId}, $inc: {votes: 1}};
    Posts.update(query, update);
    
    // now update the post's score
    post = Posts.findOne(post._id);
    Scoring.updateObject(post);
    Posts.update(post._id, {$set: {score: post.score}});
    
    return true;
  }
});