This package is extra contrib of nette/application flash messages. It use Twitter Bootstrap4 styles (alert). If you need use it please move flashes.latte into your application template directory (or your Control template directory)

composer require occ2/flashes

In presenter

<?php

namespace MyApp\Presenters;

use Nette\Application\UI\Presenter

class MyPresenter extends Presenter{
	use TFlashMessage;
	
	public function handleSomething(){
	 ... // some code
	 
	 $this->flashMessage("Error message","danger", "some comment of message", "fa fas-cross", 75, "xl", 10);
	 if($this->isAjax(){
	 	$this->redrawControl();
	 }
	 else{
	 	$this->redirect("this");
	 }
	}
}

1. $message - alert title
2. $type - alert type (success, primary, info, warning, danger)
3. $comment - comment of message
4. $icon - icon class (for example from Font Awesome)
5. $width - alert width (relative - may be 25,50,75,100)
6. $size - icon size prefix (may be xs, sm, lg, xl)
7. $delay - number of seconds to autohide flash message