A widget for displaying latest podcasts, created for the plugin seriously-simple-podcasting.

widget-latest-podcasts.php

<?php

/**
 * Display recent podcasts widget
 * 
 * Displays a list of recent podcast episodes. 
 * Based on WP_Recent_Posts widget
 * 
 * @author Karin Taliga
 */
class IVST_Widget_Recent_Podcasts extends WP_Widget {

	function __construct() {
		$widget_ops = array(
			'classname' => 'ivst_widget_recent_podcasts', 
			'description' => __( "Your site&#8217;s most recent Podcasts.", 'text-domain') 
		);
		parent::__construct( 'recent-podcasts', __( 'Recent Podcasts', 'text-domain' ), $widget_ops );
		$this->alt_option_name = 'ivst_widget_recent_podcasts';

		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_recent_podcasts', '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();
		extract( $args );

		$title = ( ! empty( $instance['title'] ) ) ? $instance['title'] : __( 'Recent Podcasts', 'text-domain' );
		$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;

		$r = new WP_Query( apply_filters( 'ivst_widget_podcasts_args', array( 'posts_per_page' => $number, 'no_found_rows' => true, 'post_status' => 'publish', 'ignore_sticky_posts' => true, 'post_type' => 'podcast' ) ) );
		if ( $r->have_posts() ) :
?>
		<?php echo $before_widget; ?>
		<?php if ( $title ) echo $before_title . $title . $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 $after_widget; ?>
<?php
		// Reset the global $the_post as this query will have stomped on it
		wp_reset_postdata();

		endif;

		$cache[ $args['widget_id'] ] = ob_get_flush();
		wp_cache_set( 'widget_recent_podcasts', $cache, '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;
		$this->flush_widget_cache();

		$alloptions = wp_cache_get( 'alloptions', 'options' );
		if ( isset( $alloptions['ivst_widget_recent_podcasts'] ) )
			delete_option( 'ivst_widget_recent_podcasts' );

		return $instance;
	}

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

	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:', 'text-domain' ); ?></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 podcasts to show:', 'text-domain' ); ?></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?', 'text-domain' ); ?></label></p>
<?php
	}
}