This guide walks you through several examples of how to use the PHP rule type in the Pro version of ReReplacer.

The PHP rule gives you the opportunity to control the display based on anything you can think of. You just need to know what PHP code you should use.

With PHP you can call on all data/information available in the variables, URL, database, etc. And then do your checks on this data. You can determine whether the rule passes or not, by ending the PHP code with a return true or false based on your checks. For example:

if( $some_variable == 'some value' ) {
   return true;
} else {
   return false;
}

Or written in a more compact way:

return $some_variable == 'some value';

Ready-to-use PHP Variables & Objects

Below are a collection of ready-to-use PHP rule scripts examples. You can also use these as examples and starting-point to create your own custom scripts.

ReReplacer checks your PHP code to see if you are referencing any commonly used Joomla objects/variables, and then creates them for you.

This means you don't have to create these variables yourself every time.

Currently ReReplacer creates these variables ready for use:

• $app The Joomla application framework
• $document or $doc The html document
• $database or $db The database
• $user The user object containing the details of the guest or current logged in user
• $Itemid The menu id of the page
• $article The article object (only available when using the code inside articles) 

Rule matching article authors

// comma separated list of author ids
$authors = '62,63,65';

// DO NOT EDIT BELOW
return isset( $article ) && isset( $article->created ) && in_array( $article->created, explode( ',', $authors ) );

Rule matching certain (parts of) email addresses

// comma separated list of (parts of) email addresses
$emails = '@yahoo.com,@hotmail.com';

// DO NOT EDIT BELOW
$pass = 0;

foreach( explode( ',', $emails ) as $email ) {
    if ( strpos( $user->email, $email ) !== false ) {
        $pass = 1;
        break;
    }
}
return $pass;

Rule matching IP addresses

// comma separated list of ip addresses
$ips = '111.111.111.111,222.222.222.222';

// DO NOT EDIT BELOW
return in_array( $_SERVER['REMOTE_ADDR'], explode( ',', $ips ) );

Rule matching IP ranges

// comma separated list of ip ranges
$ipranges = '123.255,234.255.123';

// DO NOT EDIT BELOW
$ip = $_SERVER['REMOTE_ADDR'];
$pass = 0;
foreach( explode( ',', $ipranges ) as $iprange ) {
    if ( substr( $ip.'.', 0, strlen( $iprange.'.' ) ) == $iprange.'.' ) {
        $pass = 1;
        break;
    }
}
return $pass;

Rule matching keyword (string) in page text

This will search for your search word in the output of the content area.

// string to be present in content area
$search = 'my search string';

// DO NOT EDIT BELOW
$buffer = JFactory::getDocument()->getBuffer('component');
return !is_array($buffer) && strpos($buffer, $search) !== false;

Rule matching certain menu levels

// comma separated list menu item levels
$showonlevel = '2,3';

// DO NOT EDIT BELOW
$getMenuParent = create_function( '$id', 
    '$db = JFactory::getDBO();
    $query  = "SELECT parent FROM #__menu WHERE id = ".(int) $id." LIMIT 1";
    $db->setQuery( $query );
    return $db->loadResult();
');
$level = 0;
$menuid = JRequest::getInt( 'Itemid' );
while ( $menuid ) {
    $level++;
    $menuid = $getMenuParent( $menuid );
}
return in_array( $level, explode( ',', $showonlevel ) );

You can set the first variable to what you want. level 1 would be the top level. level 2 would be a sub level, level 3 a sub-sublevel, etc.
So in above code, the rule would pass on level 2 and 3 (sub and sub-sub menu items).

Rule matching number of visits after new session

// the maximum number of pageloads after a new session
$max = 10;

// DO NOT EDIT BELOW
$session = JFactory::getSession();
return $session->get( 'session.counter', 0 ) <= $max;

This will make your item pass the check for every new session and the 10 pageloads following it.

You could use this - for instance - for showing a teaser ad or something to new visitors.

Rule matching template parameter values

// name of the template parameter to check
$param = 'someparam';
// comma separated list of possible values
$values = 'this,that';

// DO NOT EDIT BELOW
$pass = 1;
$document = JFactory::getDocument();
if ( !(
      isset( $document->params )
    &&  isset( $document->params->_registry )
    &&  isset( $document->params->_registry['_default'] )
    &&  isset( $document->params->_registry['_default']['data'] )
) ) {
  $pass = 0;
}
if ( $pass ) {
    $pass = 0;
    $params = $document->params->_registry['_default']['data'];
    if ( isset( $params->$param ) ) {
        if ( isset( $params->$param ) ) {
            $pass = in_array( $params->$param, explode( ',', $values ) );
        }
    }
}
return $pass;

So - for instance - if you want the rule to pass on all pages where the template parameter 'colorVariation' is set to 'blue' or 'green', then the first lines of the code should look like:

// name of the template parameter to check
$param = 'colorVariation';
// comma separated list of possible values
$values = 'blue,green';