App is the object that is a life-supply function for all of your views. App can either implement features on it’s own or rely on a Full Stack PHP framework (or Application) that incapsulates Agile UI.
$app = new App();
Used when application flow needs to be terminated preemptievely. For example when call-back is triggered and need to respond with some JSON.
Will be true if application is currently rendering recursively through the Render Tree.
Using of CDN servers is always better than storing external libraries locally. Most of the time CDN servers are faster (cached) and more reliable.
Method to include additional CSS stylesheet in page:
Application implements HookTrait (http://agile-core.readthedocs.io/en/develop/hook.html) and the following hooks are available: