import { computed } from '@ember/object'; import { readOnly } from '@ember/object/computed'; import { copy } from 'ember-copy'; import Service from '@ember/service'; let list = {}; export default Service.extend({ _list: computed(() => copy(list, true)), list: readOnly('_list'), init() { this._super(...arguments); list = {}; }, getIndexFor(url) { return list[url] || 1; }, setIndexFor(url, value) { list[url] = +value; }, });