Tracked Query Params

controllers.application\.js

import Controller from '@ember/controller';
import { action } from '@ember/object';
import { tracked } from '@glimmer/tracking';

export default class ApplicationController extends Controller {
  queryParams = ['appName'];

  @tracked
  appName = 'Ember Twiddle';

  get heading() {
    return `Welcome to ${this.appName}`;
  }

  @action
  updateAppName() {
    if (this.appName == 'Foo Bar') {
      this.appName = 'Ember Twiddle';
    } else {
      this.appName = 'Foo Bar';
    }
  }
}

helpers.eq\.js

import { helper } from '@ember/component/helper';

export default helper(function eq(params/*, hash*/) {
  return params[0] === params[1];
});

templates.application\.hbs

<h1>{{this.heading}}</h1>

<button {{on "click" this.updateAppName}}>
  Update app name
</button>

<LinkTo @route="application" @query={{hash appName=(if (eq this.appName "Other") "Not Other" "Other")}}>Update app name</LinkTo>

twiddle\.json

{
  "version": "0.17.1",
  "EmberENV": {
    "FEATURES": {},
    "_TEMPLATE_ONLY_GLIMMER_COMPONENTS": false,
    "_APPLICATION_TEMPLATE_WRAPPER": true,
    "_JQUERY_INTEGRATION": true
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/3.5.1/jquery.js",
    "ember": "3.18.1",
    "ember-template-compiler": "3.18.1",
    "ember-testing": "3.18.1"
  },
  "addons": {
    "@glimmer/component": "1.0.0"
  }
}