Secretary / Extend / Plugins / Plugins That Modify Variables

Some anchors let plugins modify the value of a variable that is to be used later in the code. Let's take a look at a simple example, where we allow plugins to format a title that will be displayed on the page:

<?php 
	// First define the anchor 
	define_anchor( "formatTitle" ); 
 
	// $title could be a value grabbed from the database, for example 
	$title= "Line's Music Blog"; 
	$title= call_anchor( "formatTitle", $title ); 
?>

Now, if one were to create a plugin that modified this title in some way, it would look like this:

<?php 
	hook( "formatTitle", "myFormatting" ); 
 
	function myFormatting( $title ) 
	{ 
		return '<h1>' . $title . '</h1>'; 
	} 
?>

Whatever value is returned by the plugin function will replace the original value of the variable.

<?php 
	echo $title; 
	// prints <h1>Line's Music Blog</h1> 
?>

Note too, that the value sent by call_anchor() can be of any type. If you need to send multiple values, supplying an array offers an easy workaround:

<?php 
	hook( "anchorName", "modifyAnchor" ); 
 
	// Call anchor with multiple values 
	call_anchor( "anchorName", array( 'val1', 'val2', 'val3' ) ); 
 
	// Example plugin function 
	function modifyAnchor( $vals ) 
	{ 
		$val1= $vals[0]; 
		$val2= $vals[1]; 
		$val3= $vals[2]; 
	} 
?>