WP Widget para mostrar subcategorias y post dada una cat padre

LineaCat

<?php
/**
 * Widget Post: Marca Labs - LineaCat
 * MLWidgetLineaCat Class
 */
class MLWidgetLineaCat extends WP_Widget {

    function MLWidgetLineaCat() {
        parent::WP_Widget(false, $name = 'ML Widget Cat', array('description' =>__( 'Muestra post y subcategorias de una categoria padre','')));
    }

    function widget($args, $instance) {
        extract( $args );
        $title = apply_filters('widget_title', $instance['title']);
        $ecat = apply_filters('widget_title', $instance['ecat']);        

        ?>
        
              <?php echo $before_widget; ?>
                  <?php if ( $title ) echo $before_title . $title . $after_title; ?>

                        <?php /* -------------------------------- Front End ------------------------------------ */ ?>

                        <div class="ml-widget-cat">                            

                            <?php
                              $actual_categoria_id = $ecat;
                              $categorias = get_categories(array(
                                  'parent' => $actual_categoria_id,
                                  'hide_empty' => 0
                              ));
                              ?>

                              <ul>
                                  <?php foreach($categorias as $categoria): ?> <?php /* Iterar sobre cada categoria hija */?>                            
                                    <li class=''>
                                        <h2 class="titulo"><a href="<?php echo get_category_link($categoria->cat_ID); ?>"> <?php echo ($categoria->name); ?> </a> </h2>                                
                                        <?php
                                            $posts = get_posts(array(
                                            'numberposts' => -1,
                                            'cat' => $categoria->cat_ID                                        
                                            ));
                                            ?>
                                            <ul class=""> <?php /* Posts de las subcategorias  */?>
                                                <?php foreach($posts as $elemento):?>
                                                    <li class="">
                                                        <a href="<?php echo $elemento->guid ?>">   <?php  echo $elemento->post_title; ?> </a>

                                                        <?php if(has_post_thumbnail()): ?> <?php /* feature image:  */ ?>
                                                             <a href="<?php the_permalink() ?>" rel="enlaces">  <?php the_post_thumbnail("thumbnail", array('class' => '')); ?></a>
                                                        <?php endif ?>
                                                    </li>
                                                <?php endforeach ?>
                                            </ul>
                                    </li>                             

                                  <?php endforeach; ?>
                              </ul>
                          
                        </div>
                        <?php /* -------------------------------- fin de  Front End ------------------------------------ */ ?>

              <?php echo $after_widget; ?>
        <?php
    }


    function update($new_instance, $old_instance) {
        $instance = $old_instance;
        $instance['title'] = strip_tags($new_instance['title']);     
        $instance['ecat'] = strip_tags($new_instance['ecat']);
        return $instance;
    }


    function form($instance) {
        $title = isset($instance['title']) ? esc_attr($instance['title']) : "";
        $cantidad = empty($instance['cantidad']) ? '1' : esc_attr($instance['cantidad']);
        $oby = isset($instance['oby']) ? esc_attr($instance['oby']) : "";
        $ecat = isset($instance['ecat']) ?  esc_attr($instance['ecat']) : ""; 
        ?>
            <p>
                <label for="<?php echo $this->get_field_id('title'); ?>"><?php _e('Title:','ml-widget-cat'); ?> </label>
                <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; ?>" />
            </p>

            <p>
                <label for="<?php echo $this->get_field_id('ecat'); ?>"><?php _e('Category:','ml-widget-cat'); ?> </label>
                <?php wp_dropdown_categories(array(
                        'class' =>      'widefat',
                        'id' =>         $this->get_field_id('ecat'),
                        'name' =>       $this->get_field_name('ecat'),
                        'hide_empty' => 0,
                        'hierarchical' => 1,
                        'selected' =>   $ecat
                )); ?>
            </p>

        <?php
    }

} // class MLWidgetLineaCat

add_action('widgets_init', create_function('', 'return register_widget("MLWidgetLineaCat");'));
$plugin_dir = basename(dirname(__FILE__));
load_plugin_textdomain( 'ml-widget-cat', null, $plugin_dir . '/languages/' );
?>