Ticket #16443: inside-widgets-sidebars.php

<?php

class When_Inside_Widgets_And_Sidebars 
{
        public $active_sidebar;
        public $active_widget;

        protected $_sidebars;
        protected $_sidebars_orig;
        protected $_widget_callbacks;

        public function __construct()
        {
                add_action( 'dynamic_sidebar', array(&$this, 'event_dynamic_sidebar' ) );
                add_filter( 'sidebars_widgets', array(&$this, 'filter_sidebars_widgets' ) );
        }

        public function event_dynamic_sidebar( $widget )
        {
                $this->active_widget = $widget['id'];
                foreach( (array) $this->_sidebars as $sidebar_id => $sidebar ) {
                        if ( in_array( $widget['id'], $sidebar ) ) {
                                $this->active_sidebar = $sidebar_id;
                                if ( count( $this->_sidebars[ $sidebar_id ] ) == count( $this->_sidebars_orig[ $sidebar_id ] ) ) {
                                        var_dump( sprintf( 'Starting sidebar %s!', $sidebar_id ) );
                                }
                                unset( $this->_sidebars[ $sidebar_id ][ array_search( $widget['id'], $this->_sidebars[ $sidebar_id ] ) ] );
                                break;
                        }
                }
                var_dump( sprintf( 'Starting widget %s!', $widget['id'] ) );
        }

        public function filter_sidebars_widgets( $sidebars )
        {
                global $wp_registered_widgets;

                $this->_sidebars_orig = $this->_sidebars = $sidebars;
                foreach( (array) $wp_registered_widgets as $widget ) {
                        if ( isset( $widget['id'] ) && isset( $widget['callback'] ) ) {
                                $this->_widget_callbacks[ $widget['id'] ] = $widget['callback'];        
                                $wp_registered_widgets[ $widget['id'] ]['callback'] = array(&$this, 'callable_wrapper');
                        }
                }
                return $sidebars;
        }

        public function callable_wrapper()
        {
                if ( is_callable( $this->_widget_callbacks[ $this->active_widget ] ) ) {
                        $params = func_get_args();
                        call_user_func_array( $this->_widget_callbacks[ $this->active_widget ], $params ); 
                        var_dump( sprintf( 'Ending widget %s!', $this->active_widget ) );

                        if ( empty( $this->_sidebars[ $this->active_sidebar ] ) && ! empty( $this->_sidebars_orig[ $this->active_sidebar ] ) ) {
                                var_dump( sprintf( 'Ending sidebar %s!', $this->active_sidebar ) );
                                $this->active_sidebar = null;
                        }
                        $this->active_widget = null;
                }
        }
}

$GLOBALS['inside_widgets_sidebars'] = new When_Inside_Widgets_And_Sidebars;