Ticket #9701: 9701-plugin.2.php

<?php
/**
 * #9701 Test Plugin
 *  
 * Plugin Name: #9701 Test Plugin
 * Plugin URI: http://core.trac.wordpress.org/ticket/9701
 * Description: Test Plugin to provide a Widget and a Callback to output that Widget with a new "the_widget" template tag. It's function is demonstrated within the footer.
 * Author: hakre
 * Version: 0.2
 * Author URI: http://codex.wordpress.org/User:Hakre
*/

/**
 * Test Plugin Class 
 */
class plugin9701test {

        /**
         * constructor
         * 
         * @return
         */
        function plugin9701test() {             
                
                // register widget
                add_action('widgets_init', create_function('', 'return register_widget(\'widget9701\');'));

                // footer output
                add_action('wp_footer', array($this, 'wp_footer'));
        } 
        
        function wp_footer() {          
        ?>
                <ul>
                <?php the_widget('widget9701', array('title' => 'Demo Widget w/o Sidebar')); // Self-Demo?>
                <?php the_widget('WP_Widget_Recent_Posts'); // Widget Classname Example ?>
                <?php the_widget('Recent Comments'); // Widget Name Example ?>
                </ul>
        <?php 
        }
}

$plugin9701test = new plugin9701test();

/**
 * Test Widget Class
 * 
 */
class widget9701 Extends WP_Widget {
        
        /**
         * constructor
         * 
         * @return instance of self
         */
        function widget9701() {
                parent::WP_Widget(false, '#9701 Widget');       
        }
        
        /** Echo the widget content.
         *
         * Subclasses should over-ride this function to generate their widget code.
         *
         * @param array $args Display arguments including before_title, after_title, before_widget, and after_widget.
         * @param array $instance The settings for the particular instance of the widget
         */
        function widget($args, $instance) {
                
                extract( $args );               
                extract( $instance );
                
                if (!strlen($title)) $title = '#9701 Test (Default Title)';
                
                        echo $before_widget;
                        echo $before_title . $title . $after_title;             
                ?>
                
                <div style="font-size:1.5em; overflow:scroll;">
                This widget displays it's innerst values:<br /> 
                <?php var_dump($args, $instance); ?>
                </div>

                <?php
                        echo $after_widget;
        }

        /** Update a particular instance.
         *
         * This function should check that $new_instance is set correctly.
         * The newly calculated value of $instance should be returned.
         * If "false" is returned, the instance won't be saved/updated.
         *
         * @param array $new_instance New settings for this instance as input by the user via form()
         * @param array $old_instance Old settings for this instance
         * @return array Settings to save or bool false to cancel saving
         */
        function update($new_instance, $old_instance) {                         
                return $new_instance;
        }
        
        /** Echo the settings update form
         *
         * @param array $instance Current settings
         */     
        function form($instance) {                              
                $title = attr($instance['title']);
                ?>
                <p><label for="<?php echo $this->get_field_id('title'); ?>"><?php _e('Title:'); ?> <input class="widefat" id="<?php echo $this->get_field_id('title'); ?>" name="<?php echo $this->get_field_name('title'); ?>" type="text" value="<?php echo $title; ?>" /></label></p>
                <?php 
        }
        
}

/** widget template tag
 * 
 * get a configured widgets output without the need of a sidebar and backend administration. 
 * 
 * NOTE: this is development code
 * 
 * @global WP_Widget_Factory $wp_widget_factory 
 * @global array $wp_registered_sidebars
 * 
 * @param string $widget   widget identifier
 * @param array  $settings optional widget settings
 * @param array  $args     optional sidebar options  
 * @return void
 */
function the_widget($widget, $settings = array(), $args = array()) {
        
        /* sanitize input */
        $widget = (string) $widget;
        if (!strlen($widget))
                return;
        if (!is_array($settings))
                return;
        if (!is_array($args))
                return;

        /* globals */   
        global $wp_widget_factory, $wp_registered_sidebars;     
        
        /* pull default (def) sidebar options (args) */ 
        $sidebar_id = register_sidebar( array('name' => uniqid('temp-')) );     
        $def  = $wp_registered_sidebars[$sidebar_id];
        $args = array_merge($def, $args);
                                                        
        /* get widget ($instance) */
        $instance = null;
        if (isset($wp_widget_factory->widgets[$widget])) {
                $instance = $wp_widget_factory->widgets[$widget];
        } else {
                foreach($wp_widget_factory->widgets as $value)
                        if (isset($value->name))
                                if ($value->name == $widget) {
                                        $instance = $value;
                                        break;
                                }
        }
        
        /*  display widget */
        if (is_a($instance, 'WP_Widget')) {
                $settings = apply_filters('widget_display_callback', $settings, $instance);   
                if ( false !== $settings )
                        $instance->widget($args, $settings);
        }       
        
        unregister_sidebar($sidebar_id);
}