Question:

Right now I have a working messaging system developed in Meteor where users can send private messages to each other.

The server looks like this:

// .. lot of code Meteor.publish("privateMessages", function () { return PMs.find({ to: this.userId }); }); PMs.allow({ insert: function(user, obj) { obj.from = user; obj.to = Meteor.users.findOne({ username: obj.to })._id; obj.read = false; obj.date = new Date(); return true; } }); // .. other code

When the user subscribes to privateMessages, he gets a mongo object that looks like this:

{ "to" : "LStjrAzn8rzWp9kbr", "subject" : "test", "message" : "This is a test", "read" : false, "date" : ISODate("2014-07-05T13:37:20.559Z"), "from" : "sXEre4w2y55SH8Rtv", "_id" : "XBmu6DWk4q9srdCC2" }

How can I change the object to return the username instead of the user id?

You need to do so in a way similar to how you changed username to _id. You can create a utility function:

var usernameById = function(_id) { var user = Meteor.users.findOne(_id); return user && user.username; };

<strong>Edit:</strong>

If you don't want to poll minimongo for each message, just include username instead of _id inside your message object. Since username is unique, they will be enough.

If in your app you allow users to change username, it might be a good idea to <em>also</em> keep the _id for the record.

In one of larger apps I've been working with we kept user's _id in the model (to create links to profile etc.), as well as cached his profile.name (for display purposes).

I suggest adding the collection helpers package from atmosphere. Then create a helper for PMs called toUser that returns the appropriate user. Then you can get the name using message.user.name.