收集给定类别的所有产品

Question

category有多个products。如何收集products几个categories？此代码不起作用：

controller.js

selectedCategories: Ember.computed.filter('model.categories', function(model.categories, index) {
  return (index < 10);
}).property('model.categories'),

productsOfSelectedCategories: Ember.computed('selectedCategories', 'model.products', function() {
  var selectedCategories = this.get('selectedCategories');
  var products;

  productsOfSelectedCategories.map((category) => {
    products.push(category.products);
  })

  return products;
}),

route.js

import Ember from 'ember';

export default Ember.Route.extend({
  model: function() {
    return {
      categories: this.store.find('category'),
      products: this.store.find('product'),
    };
  }
});