WordPress ランダムに投稿のリストを返します テンプレート埋め込み、ウィジェットに対応

ws-random-post.php

<?php
/*
Plugin Name: [ws] random post
Plugin URI: http://webspace.jp/
Description: ランダムにエントリーを返す
Author: hukinotou
Version: 0.1
*/

include_once 'ws-widget-random-post.php';

function ws_the_random_post($args = '') {
	echo ws_get_the_random_post($args);
}

function ws_get_the_random_post($args = '') {
	$ws_random_post = new ws_random_post();
	return $ws_random_post->execute($args);
}


class ws_random_post {

	var $offset;
	var $range;

	function __construct() {
		$this->ws_random_post_init();
	}

	function ws_random_post_init() {

	}

	function execute($args) {
		global $post;

		$args = apply_filters( 'ws_random_post_args', $args );

		/*
		 * offset: 現在日時より指定日数以上過去の記事を対象とする
		 * range: offset指定日より、指定日数間の記事を対象とする(0: 無期限）
		 */
		$defaults = array(
			'number' => 5,
			'order' => 'DESC',
			'orderby' => 'rand',
			'offset' => 0,
			'range' => 365,
			'before' => '',
			'after' => '',
			'zero' => '',
			'show_date' => false,
		);

		$r = wp_parse_args( $args, $defaults );
		extract( $r, EXTR_SKIP );

		$this->offset = $offset;
		$this->range = $range;

		$optins = array(
			array(
				'relation' => 'OR',
			),
			'post_type' => 'post',
			'post_status' => 'publish',
			'posts_per_page' => $number,
			'order' => $order,
			'orderby' => $orderby,
			'ignore_sticky_posts' => 1,
		);
		if (is_single()) {
			$optins['post__not_in'][] = $post->ID;
		}

		add_filter( 'posts_where', array($this, 'filter_where') );
		$my_query = new WP_Query($optins);
		remove_filter( 'posts_where', array($this, 'filter_where') );

		$data = '';
		if( $my_query->have_posts() ) {
			while ($my_query->have_posts()) {
				$my_query->the_post();
				$data .= '<li>';
				$data .= sprintf('<a href="%1$s">%2$s</a>', get_permalink(), get_the_title());
				if ($show_date) {
					$data .= '<span class="post-date">' . get_the_date() . '</span>';
				}
				$data .= '</li>';
			}
		} else {
			$data = $zero;
		}
		wp_reset_postdata();

		return $this->build_html($before, $after, $data);
	}

	function build_html($before, $after, $content){
		if (empty($content))
			return '';

		return $before . '<ul>' . $content . '</ul>' . $after;
	}

	function filter_where( $where = '' ) {
		$totime = date_i18n("U") - ($this->offset * 24 * 60 * 60);
		$where .= sprintf(" AND post_date <= '%s'", date('Y-m-d H:i:s', $totime));

		if ($this->range > 0) {
			$fromtime = $totime - ($this->range  * 24 * 60 * 60);
			$where .= sprintf(" AND post_date >= '%s'", date('Y-m-d H:i:s', $fromtime));

		}
		return $where;
	}
}

ws-widget-random-post.php

<?php
class ws_widget_random_post{
	function __construct() {
		add_action( 'widgets_init', array($this, 'ws_widgets_init') );
	}

	function ws_widgets_init() {
		register_widget("Widget_Random_Post");
	}
}
new ws_widget_random_post();
class Widget_Random_Post extends WP_Widget {

	function __construct() {
		$widget_ops = array('classname' => 'widget_random_post', 'description' => 'ランダムに投稿を表示する' );
		parent::__construct('random_post', 'ランダムな投稿', $widget_ops);
	}

	function widget( $args, $instance ) {
		extract($args);
		$title = ( ! empty( $instance['title'] ) ) ? $instance['title'] : __( 'Random Posts' );
		$title = apply_filters( 'widget_title', $title, $instance, $this->id_base );
		$number = ( ! empty( $instance['number'] ) ) ? absint( $instance['number'] ) : 10;
		if ( ! $number )
 			$number = 10;
		$show_date = isset( $instance['show_date'] ) ? $instance['show_date'] : false;
		$offset = ( ! empty( $instance['offset'] ) ) ? absint( $instance['offset'] ) : 0;
		if ( ! $offset )
			$offset = 0;
		$range = ( ! empty( $instance['range'] ) ) ? absint( $instance['range'] ) : 365;
		if ( ! $range )
			$range = 365;

		$args2 = array(
			'number' => $number,
			'offset' => $offset,
			'range' => $range,
			'show_date' => $show_date,
		);

		echo $before_widget;
		if ( $title )
			echo $before_title . $title . $after_title;

		ws_the_random_post($args2);

		echo $after_widget;
	}

	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;
		$instance['offset'] = (int) $new_instance['offset'];
		$instance['range'] = (int) $new_instance['range'];

		return $instance;
	}

	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;
		$offset    = isset( $instance['offset'] ) ? absint( $instance['offset'] ) : 0;
		$range     = isset( $instance['range'] ) ? absint( $instance['range'] ) : 365;
		?>
		<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>

		<p><label for="<?php echo $this->get_field_id( 'offset' ); ?>">投稿を取得しない期間（日数）:</label>
		<input id="<?php echo $this->get_field_id( 'offset' ); ?>" name="<?php echo $this->get_field_name( 'offset' ); ?>" type="text" value="<?php echo $offset; ?>" size="3" /><br />
		<small>現在日時より指定日数以上過去の記事を取得対象とします。</small></p>

		<p><label for="<?php echo $this->get_field_id( 'range' ); ?>">投稿を取得する期間（日数）:</label>
		<input id="<?php echo $this->get_field_id( 'range' ); ?>" name="<?php echo $this->get_field_name( 'range' ); ?>" type="text" value="<?php echo $range; ?>" size="3" /><br />
		<small>投稿を取得しない期間以降、指定日数間の記事を対象とします。<br />(0を設定すると無期限となります）</small></p>
		<?php
	}
}