Ticket #3875: plugin.php

<?php

//
// Filter functions, the core of the WP plugin architecture.
//

function add_filter($tag, $function_to_add, $priority = 10, $accepted_args = 1) {
        global $wp_filter;

        // So the format is wp_filter['tag']['array of priorities']['array of functions serialized']['array of ['array (functions, accepted_args)]']
        $wp_filter[$tag][$priority][serialize($function_to_add)] = array('function' => $function_to_add, 'accepted_args' => $accepted_args);
        return true;
}

function apply_filters($tag, $string) {
        global $wp_filter;

        merge_filters($tag);

        if ( !isset($wp_filter[$tag]) )
                return $string;

        $args = func_get_args();

        do{
                foreach( (array) current($wp_filter[$tag]) as $the_ )
                        if ( !is_null($the_['function']) ){
                                $args[1] = $string;
                                $string = call_user_func_array($the_['function'], array_slice($args, 1, (int) $the_['accepted_args']));
                        }

        } while ( next($wp_filter[$tag]) );

        return $string;
}

function merge_filters($tag) {
        global $wp_filter;

        if ( isset($wp_filter['all']) )
                $wp_filter[$tag] = array_merge($wp_filter['all'], (array) $wp_filter[$tag]);

        if ( isset($wp_filter[$tag]) ){
                reset($wp_filter[$tag]);
                uksort($wp_filter[$tag], "strnatcasecmp");
        }
}

function remove_filter($tag, $function_to_remove, $priority = 10, $accepted_args = 1) {
        global $wp_filter;

        unset($GLOBALS['wp_filter'][$tag][$priority][serialize($function_to_remove)]);

        return true;
}

//
// Action functions
//

function add_action($tag, $function_to_add, $priority = 10, $accepted_args = 1) {
        add_filter($tag, $function_to_add, $priority, $accepted_args);
}

function do_action($tag, $arg = '') {
        global $wp_filter, $wp_actions;

        $args = array();
        if ( is_array($arg) && 1 == count($arg) && is_object($arg[0]) ) // array(&$this)
                $args[] =& $arg[0];
        else
                $args[] = $arg;
        for ( $a = 2; $a < func_num_args(); $a++ )
                $args[] = func_get_arg($a);

        merge_filters($tag);

        if ( !isset($wp_filter[$tag]) )
                return;

        do{
                foreach( (array) current($wp_filter[$tag]) as $the_ )
                        if ( !is_null($the_['function']) )
                                call_user_func_array($the_['function'], array_slice($args, 0, (int) $the_['accepted_args']));

        } while ( next($wp_filter[$tag]) );

        if ( is_array($wp_actions) )
                $wp_actions[] = $tag;
        else
                $wp_actions = array($tag);
}

// Returns the number of times an action has been done
function did_action($tag) {
        global $wp_actions;

        return count(array_keys($wp_actions, $tag));
}

function do_action_ref_array($tag, $args) {
        global $wp_filter, $wp_actions;

        if ( !is_array($wp_actions) )
                $wp_actions = array($tag);
        else
                $wp_actions[] = $tag;

        merge_filters($tag);

        if ( !isset($wp_filter[$tag]) )
                return;

        do{
                foreach( (array) current($wp_filter[$tag]) as $the_ )
                        if ( !is_null($the_['function']) )
                                call_user_func_array($the_['function'], array_slice($args, 0, (int) $the_['accepted_args']));

        } while ( next($wp_filter[$tag]) );

}

function remove_action($tag, $function_to_remove, $priority = 10, $accepted_args = 1) {
        remove_filter($tag, $function_to_remove, $priority, $accepted_args);
}

//
// Functions for handling plugins.
//

function plugin_basename($file) {
        $file = preg_replace('|\\\\+|', '\\\\', $file);
        $file = preg_replace('/^.*wp-content[\\\\\/]plugins[\\\\\/]/', '', $file);
        return $file;
}

function register_activation_hook($file, $function) {
        $file = plugin_basename($file);
        add_action('activate_' . $file, $function);
}

function register_deactivation_hook($file, $function) {
        $file = plugin_basename($file);
        add_action('deactivate_' . $file, $function);
}

?>