discourse/app/assets/javascripts/admin/routes/admin-site-settings.js.es6

import SiteSetting from "admin/models/site-setting";

export default Discourse.Route.extend({
  queryParams: {
    filter: { replace: true }
  },

  model() {
    return SiteSetting.findAll();
  },

  afterModel(siteSettings) {
    const controller = this.controllerFor("adminSiteSettings");

    if (!controller.get("visibleSiteSettings")) {
      controller.set("visibleSiteSettings", siteSettings);
    }
  }
});