[WordPress] Mini plugin to display a random admin notice in the back-end. 📢 Use URL parameters to control count and type. Handy test tool for https://wordpress.org/plugins/wp-notification-center/

notifications-ffs.php

<?php
/**
 * Plugin Name:       Notifications FFS!
 * Description:       Sample admin notices. Use URL parameters <a href="/wp-admin/plugins.php?nffs_count=2&nffs_type=random">(sample)</a> to control count and type: <code>nffs_count=1(,2…)</code>, <code>nffs_type=random(|success|error|warning|info)</code>
 * Version:           0.2
 * Author:            Caspar Hübinger
 * Author URI:        https://profiles.wordpress.org/glueckpress
 * License: GNU       General Public License v3
 * License URI:       http://www.gnu.org/licenses/gpl-3.0.html
 * Requires PHP:      5.3.0
 * Requires WP:       4.3
 */


if( ! defined( 'ABSPATH' ) )
	exit;


/**
 * Displays a random notification in the backend.
 * @return void
 */
function notifications_ffs() {

	$i = 1;
	$count = notifications_ffs__get( 'nffs_count' );

	while ( $count >= $i ) {
		add_action( 'admin_notices', function () {
			$type = notifications_ffs__get( 'nffs_type' );
			$hell_ya = (array) notifications_ffs__gimme_notifications( $type );
			printf( '<div class="%2$s notice"><p>%1$s</p></div>', $hell_ya[ 'msg' ], $hell_ya[ 'class' ] );
		} );
		$i++;
	}

}
add_action( 'plugins_loaded', 'notifications_ffs' );


/**
 * Random notification message.
 * @return array Class name and text for message
 */
function notifications_ffs__gimme_notifications( $type = 'random' ) {
	$messages = array(
		'success' => array(
			'class' => 'notice-success',
			'msg'   => 'Something worked well. <a href="https://www.youtube.com/watch?v=vnDTSq3HmNo" target="_blank">Treat yourself</a>'
		),
		'error' => array(
			'class' => 'notice-error',
			'msg'   => 'Something is BROKEN! <a href="http://glueckpress.com/?show_me=💩" target="_blank">Show me</a>'
		),
		'warning' => array(
			'class' => 'notice-warning',
			'msg'   => 'Something <em>may</em> break. <a href="http://i.giphy.com/yEX1HlKiuIJxe.gif" target="_blank">Watch out</a>'
		),
		'info' => array(
			'class' => 'notice-info',
			'msg'   => 'You might want to know this. <a href="https://www.google.de/#q=random+facts" target="_blank">Learn more</a>'
		),
	);

	if ( 'random' === $type ) {
		shuffle( $messages );
		$pointer = mt_rand( 0, count( $messages ) - 1 );
		return $messages[ $pointer ];
	}

	return $messages[ $type ];
}

/**
 * Handle GET URL paramters.
 * @param  string $param Parameter key
 * @return mixed         Paramter value
 */
function notifications_ffs__get( $param ) {

	if ( 'nffs_count' === $param )
		return isset( $_GET[ $param ] ) ? absint( $_GET[ $param ] ) : 1;

	if ( 'nffs_type' === $param )
		return isset( $_GET[ $param ] ) ? esc_attr( $_GET[ $param ] ) : 'random';

	return false;
}