open-nomad/ui/app/routes/application.js

import { inject as service } from '@ember/service';
import { next } from '@ember/runloop';
import Route from '@ember/routing/route';
import { AbortError } from 'ember-data/adapters/errors';
import RSVP from 'rsvp';

export default Route.extend({
  config: service(),
  system: service(),

  queryParams: {
    region: {
      refreshModel: true,
    },
  },

  resetController(controller, isExiting) {
    if (isExiting) {
      controller.set('error', null);
    }
  },

  afterSetup(fn) {
    this._afterSetups || (this._afterSetups = []);
    this._afterSetups.push(fn);
  },

  beforeModel(transition) {
    return RSVP.all([this.get('system.regions'), this.get('system.defaultRegion')]).then(
      promises => {
        const queryParam = transition.queryParams.region;
        const activeRegion = this.get('system.activeRegion');
        const defaultRegion = this.get('system.defaultRegion.region');

        if (!queryParam && activeRegion !== defaultRegion) {
          // No query param: use what is in local storage, fallback to defaultRegion
          this.afterSetup(controller => {
            controller.set('region', activeRegion);
          });
        } else if (queryParam && queryParam !== activeRegion) {
          // Query param: use the query param, set that value in local storage
          this.set('system.activeRegion', queryParam);
          if (queryParam === defaultRegion) {
            // Query param === default: don't use the query param, set that value in local storage,
            // and clear the controller value.
            this.afterSetup(controller => {
              controller.set('region', null);
            });
          }
        }

        return promises;
      }
    );
  },

  // setupController doesn't refire when the model hook refires as part of
  // a query param change
  afterModel() {
    const controller = this.controllerFor('application');
    next(() => {
      (this._afterSetups || []).forEach(fn => {
        fn(controller);
      });
      this._afterSetups = [];
    });
    return this._super(...arguments);
  },

  actions: {
    didTransition() {
      if (!this.get('config.isTest')) {
        window.scrollTo(0, 0);
      }
    },

    willTransition() {
      this.controllerFor('application').set('error', null);
    },

    error(error) {
      if (!(error instanceof AbortError)) {
        this.controllerFor('application').set('error', error);
      }
    },
  },
});