mixinDigitalAssetsCollection.js

var NestedModelMixin = {
  initialize: function(undefined, options) {
    this.parent = options && options.parent;
    if ( !this.parent || ! this.nestedPath ) {
      throw "a parent model, corresponding to the parent of this Nested, " +
        "must be provided at initialization, as well as the nestedPath";
    }
  },
 
  // Path to query against is the root path of the parent model, plus the collection key, e.g.
  // [/products/999] + [/digital_assets] would be /products/999/digital_assets
  url: function() {
    return _.result(this.parent, "url") + "/" + this.nestedPath;
  }
 
};

var DigitalAssetsCollection = Backbone.Collection.extend({
  // implementation
});

Cocktail.mixin(DigitalAssetsCollection, NestedModelMixin);