Sample_Class.php

<?php

namespace Your_Namespace;

use Your_Namespace\Helpers as h;

final class Sample_Class {
	public function __start () {
		// This method is called automatically when all plugin dependencies are active.
		// But, you need put this class in your /loader.php first

		// example: Use this method to add your actions and filters hooks
		\add_action( 'admin_notices', [ $this, 'sample_notice' ], 10 );
	}

	public function sample_notice () {
		$plugin_name = h::config_get( 'NAME' );

		// see /templates/sample-notice.php file
		echo h::get_template( 'notice-info', [
			'text' => sprintf( 'Hello world from "%s" plugin', $plugin_name ),
		] );
	}

	public static function __activation () {
		// This STATIC method is called automatically on plugin activation.
		$plugin_name = h::config_get( 'NAME' );
		h::log( "INFO plugin \"$plugin_name\" activated" );
	}

	public static function __deactivation () {
		// This STATIC method is called automatically on plugin deactivation (not uninstall/deletation).
		$plugin_name = h::config_get( 'NAME' );
		h::log( "INFO plugin \"$plugin_name\" deactivated" );
	}
}