コンパクトな月別アーカイブ表示ウィジェットを追加するプラグイン

ws-widget-compact-archives.php

<?php
/*
Plugin Name: [ws] compact archive
Plugin URI: http://webspace.jp/
Description: コンパクトな月別アーカイブ表示ウィジェットを追加します
Author: hukinotou
Version: 0.1
*/
class ws_widget_compact_archives {
	function __construct() {
		add_action( 'widgets_init', array($this, 'ws_widgets_init') );
	}

	function ws_widgets_init() {
		register_widget("Widget_Compact_Archives");
	}
}
new ws_widget_compact_archives();

class Widget_Compact_Archives extends WP_Widget {

	function __construct() {
		$widget_ops = array('classname' => 'widget_compact_archive', 'description' => '投稿のコンパクトな月別アーカイブ' );
		parent::__construct('compact_archives', 'コンパクトアーカイブ', $widget_ops);
	}

	function widget( $args, $instance ) {
		extract($args);
		$c = ! empty( $instance['count'] ) ? '1' : '0';
		$title = apply_filters('widget_title', empty($instance['title']) ? __('Archives') : $instance['title'], $instance, $this->id_base);

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

		$this->get_archives(apply_filters('widget_archives_args', array('show_post_count' => $c)));

		echo $after_widget;
	}

	function update( $new_instance, $old_instance ) {
		$instance = $old_instance;
		$new_instance = wp_parse_args( (array) $new_instance, array( 'title' => '', 'count' => 0) );
		$instance['title'] = strip_tags($new_instance['title']);
		$instance['count'] = $new_instance['count'] ? 1 : 0;

		return $instance;
	}

	function form( $instance ) {
		$instance = wp_parse_args( (array) $instance, array( 'title' => '', 'count' => 0) );
		$title = strip_tags($instance['title']);
		$count = $instance['count'] ? 'checked="checked"' : '';
		?>
		<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 $this->get_field_name('title'); ?>" type="text" value="<?php echo esc_attr($title); ?>" /></p>
		<p>
			<input class="checkbox" type="checkbox" <?php echo $count; ?> id="<?php echo $this->get_field_id('count'); ?>" name="<?php echo $this->get_field_name('count'); ?>" />
			<label for="<?php echo $this->get_field_id('count'); ?>"><?php _e('Show post counts'); ?></label>
		</p>
<?php
	}

	function get_archives($args = '') {

		$defaults = array(
			'limit' => '',
			'before' => '',
			'after' => '',
			'show_post_count' => false,
			'echo' => 1,
			'order' => 'DESC',
		);

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

		$arcresults = $this->get_monthly_archives_data($r);

		$output = $this->build_html($r, $arcresults);

		if ( $echo )
			echo $output;
		else
			return $output;
	}

	function get_monthly_archives_data($args) {
		global $wpdb;
		extract( $args, EXTR_SKIP );

		if ( '' != $limit ) {
			$limit = absint($limit);
			$limit = ' LIMIT '.$limit;
		}

		$order = strtoupper( $order );
		if ( $order !== 'ASC' )
			$order = 'DESC';

		//filters
		$where = apply_filters( 'getarchives_where', "WHERE post_type = 'post' AND post_status = 'publish'", $args );
		$join = apply_filters( 'getarchives_join', '', $args );

		// get data from DB
		$query = "SELECT YEAR(post_date) AS `year`, MONTH(post_date) AS `month`, count(ID) as posts FROM $wpdb->posts $join $where GROUP BY YEAR(post_date), MONTH(post_date) ORDER BY post_date $order $limit";
		$key = md5($query);
		$cache = wp_cache_get( 'get_archives2' , 'general');
		if ( !isset( $cache[ $key ] ) ) {
			$arcresults = $wpdb->get_results($query);
			$cache[ $key ] = $arcresults;
			wp_cache_set( 'get_archives2', $cache, 'general' );
		} else {
			$arcresults = $cache[ $key ];
		}

		return $arcresults;
	}

	function build_html($args, $arcresults) {
		extract( $args, EXTR_SKIP );

		if ( !$arcresults )
			return '';

		$cur_year = -1;
		$afterafter = $after;

		$output = '<ul>'; // (1)
		foreach ( (array) $arcresults as $arcresult ) {
			if ( $cur_year != $arcresult->year ) {
				if ( $cur_year > 0 ) {
					$output .= "</ul>"; // (/3)
					$output .= "</li>\n"; // (/2)
				}
				$output .= "<li><span>"  . $arcresult->year . "年</span>"; // (2)
				$output .= "<ul>\n"; // (3)

				$cur_year = $arcresult->year;
			}

			if ( $show_post_count )
				$after = "&nbsp;({$arcresult->posts}){$afterafter}";

			$output .= "\t<li>" . $this->get_archives_link($arcresult->year, $arcresult->month, $before, $after) . "</li>\n";
		}
		$output .= "</ul>"; // (/3)
		$output .= "</li>\n"; // (/2)
		$output .= "</ul>\n"; // (/1)

		return $output;
	}

	function get_archives_link($year, $month, $before = '', $after = '') {
		global $wp_locale;

		$url = get_month_link($year, $month);
		$url = esc_url($url);

		$text = $wp_locale->get_month($month);
		$text = wptexturize($text);

		$title_text = sprintf(__('%1$s %2$d'), $wp_locale->get_month($month), $year);
		$title_text = esc_attr($title_text);

		$link_html = "$before<a href='$url' title='$title_text'>$text</a>$after";
		$link_html = apply_filters( 'get_archives_link', $link_html );

		return $link_html;
	}
}