Subnav widget

gistfile1.aw

<?php

/**
 * Subnav widget
 *
 * Base CSS:
 *
 * .widget_roots_subpages ul {
 *   margin-top: 10px;
 *   padding: 0;
 *   background-color: #fff;
 *   -webkit-border-radius: 6px;
 *   border-radius: 6px;
 *   -webkit-box-shadow: 0 1px 4px rgba(0,0,0,.065);
 *   -moz-box-shadow: 0 1px 4px rgba(0,0,0,.065);
 *   box-shadow: 0 1px 4px rgba(0,0,0,.065);
 * }
 * .widget_roots_subpages ul > li > a { margin: 0 0 -1px; font-size: 14px; padding: 9px 14px; border: 1px solid #e5e5e5; }
 * .widget_roots_subpages ul > li:first-child > a { -webkit-border-radius: 6px 6px 0 0; border-radius: 6px 6px 0 0; }
 * .widget_roots_subpages ul > li:last-child > a { -webkit-border-radius: 0 0 6px 6px; border-radius: 0 0 6px 6px; }
 * .widget_roots_subpages ul .icon-chevron-right { float: right; margin-right: -6px; opacity: .25; }
 * .widget_roots_subpages ul > li > a:hover { background-color: #f5f5f5; }
 * .widget_roots_subpages ul a:hover .icon-chevron-right { opacity: .5; }
 * .widget_roots_subpages ul .active .icon-chevron-right { opacity: .75; }
 * .widget_roots_subpages ul ul { display: none; }
 */

class Roots_Subpages_Widget extends WP_Widget {
  function Roots_Subpages_Widget() {
    $widget_ops = array('classname' => 'widget_roots_subpages', 'description' => __('Use this widget to add a navigation list for subpages', 'roots'));
    $this->WP_Widget('widget_roots_subpages', __('Subpages', 'roots'), $widget_ops);
    $this->alt_option_name = 'widget_roots_subpages';

    add_action('save_post', array(&$this, 'flush_widget_cache'));
    add_action('deleted_post', array(&$this, 'flush_widget_cache'));
    add_action('switch_theme', array(&$this, 'flush_widget_cache'));
  }

  function widget($args, $instance) {
    $cache = wp_cache_get('widget_roots_subpages', 'widget');

    if (!is_array($cache)) {
      $cache = array();
    }

    if (!isset($args['widget_id'])) {
      $args['widget_id'] = null;
    }

    if (isset($cache[$args['widget_id']])) {
      echo $cache[$args['widget_id']];
      return;
    }

    ob_start();
    extract($args, EXTR_SKIP);

    $title = apply_filters('widget_title', empty($instance['title']) ? __('Subpages', 'roots') : $instance['title'], $instance, $this->id_base);

    echo $before_widget;

    if ($title) {
      echo $before_title;
      echo $title;
      echo $after_title;
    }

    global $post;

    if (!$post->post_parent) {
      $child_of = $post->ID;
    } elseif ($post->ancestors) {
      $ancestors = end($post->ancestors);
      $child_of = $ancestors;
    }

    $subpages_args = array(
      'title_li' => '',
      'child_of' => $child_of,
      'echo'     => 0
    );

    $subpages = wp_list_pages($subpages_args);
    $subpages = str_replace('</a>', ' <i class="icon-chevron-right"></i></a>', $subpages);

    if ($subpages) { ?>
      <ul class="nav nav-list">
        <?php echo $subpages; ?>
      </ul>
    <?php }

    echo $after_widget;

    $cache[$args['widget_id']] = ob_get_flush();
    wp_cache_set('widget_roots_subpages', $cache, 'widget');
  }

  function update($new_instance, $old_instance) {
    $instance = $old_instance;
    $instance['title'] = strip_tags($new_instance['title']);
    $this->flush_widget_cache();

    $alloptions = wp_cache_get('alloptions', 'options');
    if (isset($alloptions['widget_roots_subpages'])) {
      delete_option('widget_roots_subpages');
    }

    return $instance;
  }

  function flush_widget_cache() {
    wp_cache_delete('widget_roots_subpages', 'widget');
  }

  function form($instance) {
    $title = isset($instance['title']) ? esc_attr($instance['title']) : '';
  ?>
    <p>
      <label for="<?php echo esc_attr($this->get_field_id('title')); ?>"><?php _e('Title (optional):', 'roots'); ?></label>
      <input class="widefat" id="<?php echo esc_attr($this->get_field_id('title')); ?>" name="<?php echo esc_attr($this->get_field_name('title')); ?>" type="text" value="<?php echo esc_attr($title); ?>" />
    </p>
  <?php
  }
}