自定义wordpress侧边栏小工具

/* 访问计数 */  
function record_visitors()  
{  
    if (is_singular())  
    {  
      global $post;  
      $post_ID = $post->ID;  
      if($post_ID)  
      {  
          $post_views = (int)get_post_meta($post_ID, 'views', true);  
          if(!update_post_meta($post_ID, 'views', ($post_views+1)))  
          {  
            add_post_meta($post_ID, 'views', 1, true);  
          }  
      }  
    }  
}  
add_action('wp_head', 'record_visitors');  

/// 函数名称：post_views  
/// 函数作用：取得文章的阅读次数  
function post_views($before = '(点击 ', $after = ' 次)', $echo = 1)  
{  
  global $post;  
  $post_ID = $post->ID;  
  $views = (int)get_post_meta($post_ID, 'views', true);  
  if ($echo) echo $before, number_format($views), $after;  
  else return $views;  
}  

/* 
* 自定义侧边栏小工具 
* 列出浏览次数最多的文章列表 
*/  
register_widget('Posts_view_Widget');  
class Posts_view_Widget extends WP_Widget {  
 function __construct(){//构造函数  
  $widget_ops = array('classname'=>'widget_view_posts','description'=>'显示浏览次数最多的文章列表,前提是已添加post_views统计代码');  
  $control_ops = array('width'=>250,'height'=>300);  
  $this->WP_Widget(false, '热门文章（浏览次数）', $widget_ops, $control_ops);  
 }  
 function form($instance){  
 $instance = wp_parse_args((array)$instance,array('title'=>'围观TOP10','showPosts'=>10,'show_date'=>0));//默认值  
  $title = htmlspecialchars($instance['title']);  
  $showPosts = htmlspecialchars($instance['showPosts']);  
  $show_date = htmlspecialchars($instance['show_date']);  
echo '<p style="text-align:left;"><label for="'.$this->get_field_name('title').'">标题:<input style="width:200px;" id="'.$this->get_field_id('title').'" name="'.$this->get_field_name('title').'" type="text" value="'.$title.'" /></label></p>';  
echo '<p style="text-align:left;"><label for="'.$this->get_field_name('showPosts').'">文章数量:<input style="width:200px;" id="'.$this->get_field_id('showPosts').'" name="'.$this->get_field_name('showPosts').'" type="text" value="'.$showPosts.'" /></label></p>';  
if ($instance['show_date'] == 0) {  
echo '<p style="text-align:left;"><label for="'.$this->get_field_name('show_date').'">显示时间:<select style="width:200px;"  name="'.$this->get_field_name('show_date').'" id="'.$this->get_field_id('show_date').'"><option value ="0" selected="selected">关闭</option><option value ="1">开启</option></select></label></p>';  
}else{  
echo '<p style="text-align:left;"><label for="'.$this->get_field_name('show_date').'">显示时间:<select style="width:200px;"  name="'.$this->get_field_name('show_date').'" id="'.$this->get_field_id('show_date').'"><option value ="0">关闭</option><option value ="1" selected="selected">开启</option></select></label></p>';  
}  
}  
function update($new_instance,$old_instance){  
 $instance = $old_instance;  
 $instance['title'] = strip_tags(stripslashes($new_instance['title']));  
 $instance['showPosts'] = strip_tags(stripslashes($new_instance['showPosts']));  
 $instance['show_date'] = strip_tags(stripslashes($new_instance['show_date']));  
 return $instance;  
}  
function widget($args, $instance){  
 extract($args);  
 $title = apply_filters('widget_title', emptyempty($instance['title']) ? '围观TOP10' : $instance['title']);//小工具前台标题  
 $showPosts = emptyempty($instance['showPosts']) ? 10 : $instance['showPosts'];  
 $show_date = emptyempty($instance['show_date']) ? 0 : $instance['show_date'];    
 echo $before_widget;  
 if( $title ) echo $before_title . $title . $after_title;   
 $mode = '';  
 $limit = $showPosts;  
 $term_id = 0;  
 $beforedate= '(';  
 $afterdate = ')';  
 $beforecount= '(';  
 $aftercount = ')';    
 global $wpdb, $post;  
  $output = '';  
  $mode = ($mode == '') ? 'post' : $mode;  
  $type_sql = ($mode != 'both') ? "AND post_type='$mode'" : '';  
  $term_sql = (is_array($term_id)) ? "AND $wpdb->term_taxonomy.term_id IN (" . join(',', $term_id) . ')' : ($term_id != 0 ? "AND $wpdb->term_taxonomy.term_id = $term_id" : '');  
  $term_sql.= $term_id ? " AND $wpdb->term_taxonomy.taxonomy != 'link_category'" : '';  
  $inr_join = $term_id ? "INNER JOIN $wpdb->term_relationships ON ($wpdb->posts.ID = $wpdb->term_relationships.object_id) INNER JOIN $wpdb->term_taxonomy ON ($wpdb->term_relationships.term_taxonomy_id = $wpdb->term_taxonomy.term_taxonomy_id)" : '';  
   // database query  
  $most_viewed = $wpdb->get_results("SELECT ID, post_date, post_title, (meta_value+0) AS views FROM $wpdb->posts LEFT JOIN $wpdb->postmeta ON ($wpdb->posts.ID = $wpdb->postmeta.post_id) $inr_join WHERE post_status = 'publish' AND post_password = '' $term_sql $type_sql AND meta_key = 'views' GROUP BY ID ORDER BY views DESC LIMIT $limit");  
  if ($most_viewed) {  
   foreach ($most_viewed as $viewed) {  
    $post_ID    = $viewed->ID;  
    $post_views = number_format($viewed->views);  
    $post_title = esc_attr($viewed->post_title);  
    $get_permalink = esc_attr(get_permalink($post_ID));  
    $output .= "<li><a href=\"$get_permalink\">$post_title</a>";  
    if ($show_date) {  
      $posted = date(get_option('date_format'), strtotime($viewed->post_date));  
      $output .= "$beforedate $posted $afterdate";  
    }  
    $output .= "$beforecount $post_views $aftercount</li>";  
   }  
  } else {  
   $output = "<li>N/A</li>";  
  }  
  echo $output;  
 echo $after_widget;  
}  
}