Wordpress functions.php addition: Columns to display custom fields

more-columns-wp-admin.php

/**
* This will add an additional columns called 'Students, Background, Outcome'to the custom post type of 'casestudies'.
* These new columns display the specified custom fields of a post.
*/

add_action("manage_posts_custom_column", "casestudies_custom_columns");
add_filter("manage_edit-casestudies_columns", "setup_casestudies_admin_columns");

function setup_casestudies_admin_columns($columns)
{
    $columns = array(
        "cb" => "<input type=\"checkbox\" />",
        "title" => "Title",
        "students" => "Students", 
        "background" => "Background",        
        "outcome" => "Outcome",
        'date' => 'Published'
    );
    return $columns;
}

function casestudies_custom_columns($column)
{
    global $post;

        switch( $column ):
            case "ID":
                echo $post->ID;
                break;
            case "title":
                echo $post->post_title;
                break;
            case "students":
                echo get_post_meta( $post->ID, "students", TRUE );
                break; 
            case "background":
                echo get_post_meta( $post->ID, "background", TRUE );
                break;                
            case "outcome":
                echo get_post_meta( $post->ID, "outcome", TRUE );
                break;
        endswitch;
}

/**
* This will add an additional column called 'Image'to the custom post type of 'photogallery'.
* This column will display the featured image of a post.
*/

add_action("manage_posts_custom_column", "photogallery_custom_columns");
add_filter("manage_edit-photo-gallery_columns", "setup_photogallery_admin_columns");

function setup_photogallery_admin_columns($columns)
{
    $columns = array(
        "cb" => "<input type=\"checkbox\" />",
        "title" => "Title",
        "image" => "Image", 
        'date' => 'Published'
    );
    return $columns;
}

function photogallery_custom_columns($column)
{
    global $post;

        switch( $column ):
            case "ID":
                echo $post->ID;
                break;
            case "title":
                echo $post->post_title;
                break;
            case "image":
                echo the_post_thumbnail(array(75,75));
                break; 
        endswitch;
}