discourse-docs/assets/javascripts/discourse/controllers/docs.js

import Controller, { inject as controller } from "@ember/controller";
import { action } from "@ember/object";

export default class DocsController extends Controller {
  @controller("docs.index") indexController;

  @action
  updateSelectedCategories(category) {
    this.indexController.send("updateSelectedCategories", category);
    return false;
  }

  @action
  updateSelectedTags(tag) {
    this.indexController.send("updateSelectedTags", tag);
    return false;
  }

  @action
  performSearch(term) {
    this.indexController.send("performSearch", term);
    return false;
  }
}