titlechange.php

<?php
/**
 * System Plugin for Joomla! - Title change
 *
 * @author     Viviana Menzel <vivianamenzel@dr-menzel-it.de>
 * @copyright  Copyright 2015 Viviana Menzel
 * @license    GNU Public License version 3 or later
 * @link       http://www.dr-menzel-it.de/
 */

defined('_JEXEC') or die;

use Joomla\CMS\Plugin\CMSPlugin;

/**
 * Class PlgSystemTitlechange
 *
 * @since  1.0.0
 */
class PlgSystemTitlechange extends JPlugin
{
	/**
	 * var  JApplicationCms
	 */
	protected $app;

	/**
	 * Event method onAfterRender
	 *
	 * @return  void
	 *
	 * @since   1.0.0
	 */
	public function onAfterRender()
	{
		// Don't run this plugin in the Admin
		if ($this->app->isClient('administrator'))
		{
			return;
		}

		$body = $this->app->getBody();

		if (strpos($body, '{titlechange') !== false)
		{
			$body = $this->replaceTags($body);
			$this->app->setBody($body);
		}
	}
	/**
	 * Method to replace tags in a text
	 *
	 * @param   string  $text  Text to replace tags in
	 *
	 * @return  string
	 *
	 * @since   1.0.0
	 */
	public function replaceTags($text)
	{
		// This regEx search for {titlechange:myClass my text} parts inside a <title></title> tag, should only appear once...
		while (preg_match_all('/<title>([^\{\}]*){titlechange:([^\s}]+)\ ([^\}]+)\}(.*?)<\/title>/', $text, $matches))
		{
			foreach ($matches[2] as $matchIndex => $match)
			{
				$tag    = $matches[0][$matchIndex];
				$group1 = $matches[1][$matchIndex];
				$group3 = $matches[3][$matchIndex];
				$group4 = $matches[4][$matchIndex];
				$text   = str_replace($tag, "<title>" . $group1 . $group3 . $group4 . "</title>", $text);
			}
		}

		// This regEx search for {titlechange:myClass [([^\s}]+)\] my text [([^\}]+)\]} parts
		if (preg_match_all('/{titlechange:([^\s}]+)\ ([^\}]+)\}/', $text, $matches))
		{
			foreach ($matches[2] as $matchIndex => $match)
			{
				$tag       = $matches[0][$matchIndex];
				$classname = $matches[1][$matchIndex];
				$text      = str_replace($tag, "<span class=" . $classname . ">" . $match . "</span>", $text);
			}
		}

		return $text;
	}
}