// no direct access
defined( '_JEXEC' ) or die( 'Restricted access' );


jimport( 'joomla.plugin.plugin' );


/**
 * Scripty plug-in provides a workaround for the problem of script tags being filtered. It was
 * designed for advanced users, if you do not know what you are doing security can be compromised!
 */
class plgContentScripty extends JPlugin
{
	const _tag = "scripty";
	
	/**
	 * Constructor
	 *
	 * For php4 compatibility we must not use the __constructor as a constructor for plugins
	 * because func_get_args ( void ) returns a copy of all passed arguments NOT references.
	 * This causes problems with cross-referencing necessary for the observer design pattern.
	 *
	 * @access	protected
	 * @param	object	$subject The object to observe
	 * @param 	array   $config  An array that holds the plugin configuration
	 * @since	1.0
	 */
	function plgContentScripty(&$subject, $config)
	{
		parent::__construct( $subject, $config );


		// Do some extra initialisation in this constructor if required
	}
	
	/**
	 * onPrepareContent event handler. It replaces all entries of {scripty}tag with the
	 * script HTML tag.
	 * @param $row
	 * @param $params
	 * @param $page
	 * @return boolean Returns true if successful
	 */
	function onPrepareContent(&$row, &$params, $page = 0) 
	{
	  	$tag = self::_tag;
	  	$alternativetag = $this->params->def('alternativetag', '');
	  	
	  	if ($alternativetag != '')
	  	{
	  		$tag = '(' . $tag . '|' . $alternativetag . ')'; 		
	  	}
	  	else
	  	{
	  		$tag = '(' . $tag . ')';
	  	}
	    
	  	$regex = "#{" . $tag . "(?:\s| )*(.*?)}([\s\S]*?){/\\1}#s";
	    // register the regular expression to invoke our replacer in case Joomla finds the matches
	    $row->text = preg_replace_callback($regex, array($this,'replacer'), $row->text);
	    
	    return true;
	}


  /**
   * Provides a replacement text for the given match. This provides a call back function for the
   * regular expression matcher. It wrap the text in <script></script> as needed
   * @param array $matches The match that was found
   * @return string The replacement string 
   */
  private function replacer(&$matches) 
  {
    $args = $matches[2];
    $text = $matches[3];
    $src = '';
    
    if($this->params->def('include', '') === '1' && $args !== '')
    {
    	$key_value = explode("=", $args);
    	
    	if(trim($key_value[0]) === 'src')
    	{
    		$src = trim($key_value[1]);
    	}
    }
    
    if($src === '')
    {
    	$prolog = '<script type="text/javascript">';
    }
    else
    {
    	$prolog = '<script type="text/javascript" src="' . $src . '">';
    }
    
    $epilog = '</script>';


    $text = $prolog . $text . $epilog;


    return $text;
  }
}

<?xml version="1.0" encoding="utf-8"?>
<install version="1.5.2" type="plugin" group="content" method="upgrade">
	<name>Content - Scripty</name>
	<author>Michael Yagudaev</author>
	<creationDate>July 2010</creationDate>
	<copyright>Copyright (C) 2010 yagudaev.com. All rights reserved.</copyright>
	<license>GNU General Public License</license>
	<authorEmail>michaelyagudaev [at] gmail.com</authorEmail>
	<authorUrl>http://www.yagudaev.com/</authorUrl>
	<version>0.1</version>
	<description>Scripty is a small plug-in that provides a workaround to the problem 
		of filtered script tags (&lt;script&gt;). To use it simply place the scripty opening
		and closing tags where you would normally place the script tags in your html.
	</description>
	<files>
		<filename plugin="scripty">scripty.php</filename>
	</files>
	<params>
  		<param name="include" type="radio" default="0" label="Allow includes" description="Allows the user to include a script">
  			<option value="0">No</option>
			<option value="1">Yes</option>
		</param>
		<param name="alternativetag" type="text" default="" label="Alternative tag to trigger the plugin usage." description="If you would like to use something other than {scripty}. For example: script" />
	</params>
</install>

 
{*scripty*} 
	alert("hello javascript on joomla!"); 
{*/script*} 

 
{*scripty src="/js/my_awesome_script.js"*} 
	no javascript 
{*/scripty*}