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copied!<p>Okay, </p> <p>I am not 100% exactly what you want to do, but I have an idea.</p> <p>Maybe you mean something like this:</p> <pre><code>class View { public $hooks = array('getsomeVar'); public $hooks_functions = array(); public $attributes = array(); public function __set($k,$v) { $this->attributes[$k] = $v; } public function __get($k) { if (isset($this->attributes[$k])){ $hooks = $this->get_functions_by_hook('get' . $k); if (!empty($hooks)){ foreach ($hooks as $klass=>$methods) { if (class_exists($klass)){ $class = new $klass(); foreach ($methods as $method) { if (method_exists($class,$method)){ $this->attributes[$k] = $class->$method($this->attributes[$k]); } } } } } return $this->attributes[$k]; } else { throw new Exception($k . " is not a view variable"); } } public function register_filter($name,$class,$method) { if (in_array($name,$this->hooks)){ $this->hooks_functions[$name][$class][] = $method; } else { throw new Exception($name . ' is not a valid hook'); } } public function get_functions_by_hook($name) { if (array_key_exists($name,$this->hooks_functions)){ return $this->hooks_functions[$name]; } return array(); } } class MyPlugin { public function fix_string($str) { return str_replace("ruby",'php',$str); } } $v = new View(); $v->someVar = 'ruby is great'; $v->register_filter('getsomeVar','MyPlugin','fix_string'); echo $v->someVar; </code></pre> <p>or you can use this method, which is more event like. Again sample code, but you should be able to cannabalize it.</p> <pre><code>class EventDispatcher { public static $listeners = array(); public static function registerListener(&$instance) { if (!in_array($isntance,self::$listeners)){ array_push(self::$listeners,$instance); } } public static function dispatchEvent($name,&$value) { foreach (self::$listeners as $listener) { if (method_exists($listener,'interests')){ $funcs = $listener->interests(); if (array_key_exists($name,$funcs)){ foreach ($funcs as $f) { $value = $listener->$f($value); } } } } } } class Plugin { public static function registerPlugin($class_name) { if (class_exists($class_name)){ EventDispatcher::registerListener(new $class_name()); } } } class Model { public function __construct() { EventDispatcher::registerListener($this); } public function special($value) { echo "I got called too!\n\n"; return $value; } public function interests() { return array( "getsomeVar" => "special", ); } } class View { public $attributes = array(); public function __set($k,$v) { $this->attributes[$k] = $v; } public function __get($k) { if (isset($this->attributes[$k])){ EventDispatcher::dispatchEvent('get' . $k,$this->attributes[$k]); return $this->attributes[$k]; } else { throw new Exception($k . " is not a view variable"); } } } class MyPlugin { public function fix_string($str) { return str_replace("ruby",'php',$str); } public function interests() { return array( "getsomeVar" => "fix_string", ); } } Plugin::registerPlugin('MyPlugin'); $model = new Model(); $v = new View(); $v->someVar = 'ruby is great'; echo $v->someVar; </code></pre> <p>This is just some sample code, I don't do it this way at all, but it seems like it may be what you are talking about.</p> <p>Cheers, Jason</p> <p>Addendum: </p> <p>Most of this stuff is about the WP codebase.</p> <p>WP accesses variables set in the global scope that are modified like so:</p> <pre><code>function add_filter($tag, $function_to_add, $priority = 10, $accepted_args = 1) { global $wp_filter, $merged_filters; $idx = _wp_filter_build_unique_id($tag, $function_to_add, $priority); $wp_filter[$tag][$priority][$idx] = array('function' => $function_to_add, 'accepted_args' => $accepted_args); unset( $merged_filters[ $tag ] ); return true; } </code></pre> <p>It has some other functions like, has_filter etc...</p> <pre><code>function apply_filters($tag, $value) { global $wp_filter, $merged_filters, $wp_current_filter; $args = array(); $wp_current_filter[] = $tag; // Do 'all' actions first if ( isset($wp_filter['all']) ) { $args = func_get_args(); _wp_call_all_hook($args); } if ( !isset($wp_filter[$tag]) ) { array_pop($wp_current_filter); return $value; } // Sort if ( !isset( $merged_filters[ $tag ] ) ) { ksort($wp_filter[$tag]); $merged_filters[ $tag ] = true; } reset( $wp_filter[ $tag ] ); if ( empty($args) ) $args = func_get_args(); do { foreach( (array) current($wp_filter[$tag]) as $the_ ) if ( !is_null($the_['function']) ){ $args[1] = $value; $value = call_user_func_array($the_['function'], array_slice($args, 1, (int) $the_['accepted_args'])); } } while ( next($wp_filter[$tag]) !== false ); array_pop( $wp_current_filter ); return $value; } </code></pre> <p>This is not an event driven system, it's a method lookup table which is just a giant hash that looks up the user defined functions to call.</p> <p>apply_filters, and all plugin like functions are called procedurally as the code is rendered, here is an example</p> <pre><code> if ( $prefixed ) { $value = apply_filters("pre_$field", $value); $value = apply_filters("${field_no_prefix}_save_pre", $value); } else { $value = apply_filters("pre_post_$field", $value); $value = apply_filters("${field}_pre", $value); } </code></pre> <p>Or for actions, in an actual template view like so:</p> <pre><code><p class="submit"><input type="submit" class="button" name="submit" value="<?php esc_attr_e('Add Category'); ?>" /></p> <?php do_action('edit_link_category_form', $category); ?> </form> </code></pre>

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