Use of the at sign ("@")


#1

Hello!

I’m finally working on an Ember.js project instead of just reading about Ember.js. :smile: Hallelujah!

I’m trying to just move forward instead of dawdling at every new concept, which is my Achilles heel, but I thought I’d ask about the use of the at sign. I have seen it in @each (not that I fully get it) but now I’ve seen @set and @store. I’ve tried finding a reference to this in the Ember.js guides, but I’ve come up empty.

TIA,

Ali

P.S. https://en.wikipedia.org/wiki/At_sign


#2

@set and @store are coffeescript…which compiles to this.set and this.store. Not really an ember thing (but understandably confusing given the use of @each!)


#3

Interesting!! Thanks very much, Spencer.


#4

There is also an important place where the @ sign is used in Ember in javascript, which is when observing the property of each item in an array of objects.

For instance, if I had an ember object like this:

var User = Ember.Object.extend({
  name: null
});

var Names = Ember.Object.extend({
  users: [], // an array of User objects, each of which has a 'name' property

  allNames: function(){
    return this.get('users').mapBy('name').join(',');
  }.property('users.@each.name');
});

The value of allNames will update whenever any of its users’ name changes. docs here