A couple weeks ago I released the Portfolio Theme, which uses custom post types to display images and portfolio information. Since the featured image is a key component of the post type, I wanted a way to display that from the post dashboard- along with the title, taxonomy, author, comments, and post date.

I couldn’t find any code snippets available that did exactly what I wanted, but I did get close with WP Engineer’s post about adding thumbnails to post and pages and Shiba’s post about adding custom post type columns.

You’re welcome to download the Portfolio Theme and see how all the code was included. The code below is just the specific part about adding columns to edit screen.

Note, I already have a custom post type “portfolio” built. If you wanted to use these columns with a “art” post type for instance, you would need to swap out the name.

//  Add Columns to Portfolio Edit Screen
add_filter("manage_edit-portfolio_columns", "portfolio_edit_columns");
add_action("manage_posts_custom_column",  "portfolio_columns_display", 10, 2);
add_theme_support( 'post-thumbnails', array( 'portfolio' ) );
function portfolio_edit_columns($portfolio_columns){
	$portfolio_columns = array(
		"cb" => "<input type=\"checkbox\" />",
		"title" => _x('Title', 'column name'),
		"thumbnail" => __('Thumbnail'),
		"portfolio-tags" => __('Tags'),
		"author" => __('Author'),
		"comments" => __('Comments'),
		"date" => __('Date'),
	);
	$portfolio_columns['comments'] = '<div class="vers"><img alt="Comments" src="' . esc_url( admin_url( 'images/comment-grey-bubble.png' ) ) . '" /></div>';
	return $portfolio_columns;
}
function portfolio_columns_display($portfolio_columns, $post_id){
	switch ($portfolio_columns)
	{
		// Code from: http://wpengineer.com/display-post-thumbnail-post-page-overview
		case "thumbnail":
			$width = (int) 35;
			$height = (int) 35;
				$thumbnail_id = get_post_meta( $post_id, '_thumbnail_id', true );
				// image from gallery
				$attachments = get_children( array('post_parent' => $post_id, 'post_type' => 'attachment', 'post_mime_type' => 'image') );
				if ($thumbnail_id)
					$thumb = wp_get_attachment_image( $thumbnail_id, array($width, $height), true );
				elseif ($attachments) {
					foreach ( $attachments as $attachment_id => $attachment ) {
						$thumb = wp_get_attachment_image( $attachment_id, array($width, $height), true );
					}
				}
					if ( isset($thumb) && $thumb ) {
						echo $thumb;
					} else {
						echo __('None');
					}
			break;
		case "portfolio-tags":
			if ($tag_list = get_the_term_list( $post->ID, 'portfolio-tags', '', ', ', '' ) ) {
				echo $tag_list;
			} else {
					echo __('None');
				}
			break;
	}
}