What do you prefer?

backbone.js

// In Backbone, when passing a collection around, do you prefer to inject the
// collection into the view, or store it on a global namespace?

// Injection
var SomeCollectionView = Backbone.View.extend({
  initialize: function() {
    // this.collection
  }
});
new SomeCollectionView({ collection: App.myCollection });


// Or store and reference collection on namespace.
var SomeCollectionView = Backbone.View.extend({
  initialize: function() {
    // App.myCollection
  }
});
new SomeCollectionView;

Dependency injection is the best way to handle that. As pointed before, it makes unit testing easier and makes the app more portable.