Add Featured Image Thumbnail to Posts Page

Customize the information that is displayed on the ‘posts’ page

Adding a column labeled “Thumbnail” (and delete the “Comments” column).

add_filter( 'manage_edit-post_columns', 'set_columns' );
function set_columns($columns) {
	$columns['thumbnail'] = 'Thumbnail';
	unset( $columns['comments'] );
	return $columns;

Now we need to tell WordPress what to do with this new “Thumbnail” space. Here, we’re checking for the existence of a featured image and displaying it, or noting that there is no thumbnail.

add_action( 'manage_posts_custom_column', 'fill_columns' );
function fill_columns($column) {
	global $post;
	switch($column) {
		case 'thumbnail' :
			if (has_post_thumbnail($post->ID))
				echo get_the_post_thumbnail($post->ID, array(50, 50));
				echo '<em>no thumbnail</em>';

Customize the Favorites Menu

Ever use that favorites menu up by the “Howdy” greeting? I never really did until I started customizing the options.

One of my favorites is adding a link to the master options page (wp-admin/options.php)

add_filter('favorite_actions', 'custom_favorites');
function custom_favorites($actions) {
		$actions['options.php'] = array('All Settings', 'unfiltered_html'); // this line adds an item
		return $actions;

Or, remove the menu entirely

add_filter('favorite_actions', 'remove_favorites');
function remove_favorites($actions) {
		$actions = array(); 
		return $actions;

Change Admin Footer Text

If you need to customize the WordPress administration area, you’ll find this useful.

add_filter('admin_footer_text', 'left_admin_footer_text_output'); //left side
function left_admin_footer_text_output($text) {
    $text = 'How much wood would a woodchuck chuck?';
    return $text;

add_filter('update_footer', 'right_admin_footer_text_output', 11); //right side
function right_admin_footer_text_output($text) {
    $text = "That's purely hypothetical.";
    return $text;