WordPress侧边栏，小工具开发与使用

一个新开发的主题没有侧边栏，需要在自己注册侧边栏，在functions.php中添加代码

//注册侧边栏if ( function_exists('register_sidebar') ) {     register_sidebar(array(       'name'=>'首页边栏',     'id'=>'sidebar1',      'before_widget' => '<li id="%1$s" class="sidebar_li %2$s">',       'after_widget' => '</li>',       'before_title' => '<h3>',       'after_title' => '</h3>',     ));     register_sidebar(array(       'name'=>'侧边栏',     'id'=>'sidebar3',      'before_widget' => '<li id="%1$s" class="sidebar_li %2$s">',       'after_widget' => '</li>',       'before_title' => '<h3>',       'after_title' => '</h3>',     ));       register_sidebar(array(       'name'=>'脚部边栏',     'id'=>'sidebar2',      'before_widget' => '<li id="%1$s" class="sidebar_li %2$s">',       'after_widget' => '</li>',       'before_title' => '<h3>',       'after_title' => '</h3>',     ));    }

这里注册三个侧边栏，随后在小工具中可以看到三个侧边栏

接下来就是要在目录页或者文章页调用侧边栏了代码如下：

<ul id="sidebar"><?php if ( ! dynamic_sidebar("<span style="font-family: Arial, Helvetica, sans-serif;">sidebar3</span><span style="font-family: Arial, Helvetica, sans-serif;">") ) : ?></span><li>没有就显示默认的</li><li><span style="font-family: Arial, Helvetica, sans-serif;">没有就显示默认的</span><span style="font-family: Arial, Helvetica, sans-serif;"></li></span><?php endif; ?></ul>

左边小工具的开发，下边是WordPress默认的近期文章

</pre><p></p><pre name="code" class="php"></pre><pre name="code" class="php"><?php/** * Recent_Posts widget class * * @since 2.8.0 */class WP_Widget_Recent_Posts extends WP_Widget {/** * classname指你自己的class * description 是你自己的描述 * parent::__construct('你的id唯一','你的小工具的名字', $widget_ops); * */public function __construct() {$widget_ops = array('classname' => 'widget_recent_entries', 'description' => __( "Your site’s most recent Posts.") );parent::__construct('recent-posts', __('Recent Posts'), $widget_ops);//下面的不需要一般不用写$this->alt_option_name = 'widget_recent_entries';add_action( 'save_post', array($this, 'flush_widget_cache') );add_action( 'deleted_post', array($this, 'flush_widget_cache') );add_action( 'switch_theme', array($this, 'flush_widget_cache') );}/** * 前台展示的方法 * */public function widget($args, $instance) {$cache = array();if ( ! $this->is_preview() ) {$cache = wp_cache_get( 'widget_recent_posts', 'widget' );}if ( ! is_array( $cache ) ) {$cache = array();}if ( ! isset( $args['widget_id'] ) ) {$args['widget_id'] = $this->id;}if ( isset( $cache[ $args['widget_id'] ] ) ) {echo $cache[ $args['widget_id'] ];return;}ob_start();$title = ( ! empty( $instance['title'] ) ) ? $instance['title'] : __( 'Recent Posts' );/** This filter is documented in wp-includes/default-widgets.php */$title = apply_filters( 'widget_title', $title, $instance, $this->id_base );$number = ( ! empty( $instance['number'] ) ) ? absint( $instance['number'] ) : 5;if ( ! $number )$number = 5;$show_date = isset( $instance['show_date'] ) ? $instance['show_date'] : false;/** * Filter the arguments for the Recent Posts widget. * * @since 3.4.0 * * @see WP_Query::get_posts() * * @param array $args An array of arguments used to retrieve the recent posts. */$r = new WP_Query( apply_filters( 'widget_posts_args', array('posts_per_page'      => $number,'no_found_rows'       => true,'post_status'         => 'publish','ignore_sticky_posts' => true) ) );if ($r->have_posts()) :?><?php echo $args['before_widget']; ?><?php if ( $title ) {echo $args['before_title'] . $title . $args['after_title'];} ?><ul><?php while ( $r->have_posts() ) : $r->the_post(); ?><li><a href="<?php the_permalink(); ?>"><?php get_the_title() ? the_title() : the_ID(); ?></a><?php if ( $show_date ) : ?><span class="post-date"><?php echo get_the_date(); ?></span><?php endif; ?></li><?php endwhile; ?></ul><?php echo $args['after_widget']; ?><?php// Reset the global $the_post as this query will have stomped on itwp_reset_postdata();endif;if ( ! $this->is_preview() ) {$cache[ $args['widget_id'] ] = ob_get_flush();wp_cache_set( 'widget_recent_posts', $cache, 'widget' );} else {ob_end_flush();}}/** * 更新一般直接是将数据处理一下直接返回 * */public function update( $new_instance, $old_instance ) {$instance = $old_instance;$instance['title'] = strip_tags($new_instance['title']);$instance['number'] = (int) $new_instance['number'];$instance['show_date'] = isset( $new_instance['show_date'] ) ? (bool) $new_instance['show_date'] : false;$this->flush_widget_cache();$alloptions = wp_cache_get( 'alloptions', 'options' );if ( isset($alloptions['widget_recent_entries']) )delete_option('widget_recent_entries');return $instance;}public function flush_widget_cache() {wp_cache_delete('widget_recent_posts', 'widget');}/** * 后台展示方法 * */public function form( $instance ) {$title     = isset( $instance['title'] ) ? esc_attr( $instance['title'] ) : '';$number    = isset( $instance['number'] ) ? absint( $instance['number'] ) : 5;$show_date = isset( $instance['show_date'] ) ? (bool) $instance['show_date'] : false;?><p><label for="<?php echo $this->get_field_id( 'title' ); ?>"><?php _e( 'Title:' ); ?></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( 'number' ); ?>"><?php _e( 'Number of posts to show:' ); ?></label><input id="<?php echo $this->get_field_id( 'number' ); ?>" name="<?php echo $this->get_field_name( 'number' ); ?>" type="text" value="<?php echo $number; ?>" size="3" /></p><p><input class="checkbox" type="checkbox" <?php checked( $show_date ); ?> id="<?php echo $this->get_field_id( 'show_date' ); ?>" name="<?php echo $this->get_field_name( 'show_date' ); ?>" /><label for="<?php echo $this->get_field_id( 'show_date' ); ?>"><?php _e( 'Display post date?' ); ?></label></p><?php}}register_widget('IntroduceViews');?>

自己可以根据实例修改，例如在你的主题下新建一个小工具LastPost.php，将上面的代码拷贝，修改保存，最后在functions.php中添加

include_once (TEMPLATEPATH.'/LastPost.php');

这样刷新后台小工具，就可以看到你自己写的小工具了。