Quesion about line 77 of posts.js

soulmachine · September 13, 2015, 11:53pm

DiscoverMeteor/Microscope/blob/master/lib/collections/posts.js#L77


    _id: postId
  };
},


upvote: function(postId) {
  check(this.userId, String);
  check(postId, String);
  
  var affected = Posts.update({
    _id: postId, 
    upvoters: {$ne: this.userId}
  }, {
    $addToSet: {upvoters: this.userId},
    $inc: {votes: 1}
  });
  
  if (! affected)
    throw new Meteor.Error('invalid', "You weren't able to upvote that post");
}
});

upvoters is an array, why can’t I use the $in operator to detect wether the array contains the userId, such as upvoters: {$in: this.userId}?

energistic · September 14, 2015, 3:33am

I think that update is saying: ‘if the user is not already an upvoter, then do the upvote’. You would use $in for a removeUpvote method.

soulmachine · September 14, 2015, 5:39pm

From here

github.com

DiscoverMeteor/Microscope/blob/master/server/fixtures.js#L22


});
var sacha = Meteor.users.findOne(sachaId);


var telescopeId = Posts.insert({
  title: 'Introducing Telescope',
  userId: sacha._id,
  author: sacha.profile.name,
  url: 'http://sachagreif.com/introducing-telescope/',
  submitted: new Date(now - 7 * 3600 * 1000),
  commentsCount: 2,
  upvoters: [], votes: 0
});


Comments.insert({
  postId: telescopeId,
  userId: tom._id,
  author: tom.profile.name,
  submitted: new Date(now - 5 * 3600 * 1000),
  body: 'Interesting project Sacha, can I get involved?'
});

We can see that upvoters is an array