Add Custom Admin Column

Add Custom Admin Column

This snippet adds a custom column to the WordPress admin posts list. The example shows how to display featured image thumbnails, but you can customize it to display any post meta or custom field.

// Add the custom column header
function add_featured_image_column($columns) {
    // Insert after title column
    $new_columns = array();
    foreach ($columns as $key => $value) {
        $new_columns[$key] = $value;
        if ($key === 'title') {
            $new_columns['featured_image'] = __('Featured Image', 'textdomain');
        }
    }
    return $new_columns;
}
add_filter('manage_posts_columns', 'add_featured_image_column');
add_filter('manage_pages_columns', 'add_featured_image_column');

// Populate the custom column
function show_featured_image_column($column_name, $post_id) {
    if ($column_name === 'featured_image') {
        $thumbnail = get_the_post_thumbnail($post_id, array(80, 80));
        echo $thumbnail ? $thumbnail : '—';
    }
}
add_action('manage_posts_custom_column', 'show_featured_image_column', 10, 2);
add_action('manage_pages_custom_column', 'show_featured_image_column', 10, 2);

// Make the column sortable (for post meta fields)
function make_column_sortable($columns) {
    $columns['featured_image'] = 'featured_image';
    return $columns;
}
add_filter('manage_edit-post_sortable_columns', 'make_column_sortable');

// Handle the sorting query
function sort_by_column($query) {
    if (!is_admin() || !$query->is_main_query()) {
        return;
    }

    if ($query->get('orderby') === 'featured_image') {
        $query->set('meta_key', '_thumbnail_id');
        $query->set('orderby', 'meta_value_num');
    }
}
add_action('pre_get_posts', 'sort_by_column');

// Add CSS to set column width
function custom_admin_column_css() {
    echo '<style>
        .column-featured_image {
            width: 100px;
            text-align: center;
        }
        .column-featured_image img {
            max-width: 80px;
            height: auto;
            border-radius: 4px;
        }
    </style>';
}
add_action('admin_head', 'custom_admin_column_css');

Common Use Cases

Display Post Meta:

function show_custom_field_column($column_name, $post_id) {
    if ($column_name === 'price') {
        echo get_post_meta($post_id, 'product_price', true) ?: '—';
    }
}

Show Taxonomy Terms:

function show_taxonomy_column($column_name, $post_id) {
    if ($column_name === 'product_category') {
        $terms = get_the_term_list($post_id, 'product_cat', '', ', ', '');
        echo $terms ?: '—';
    }
}

Display Word Count:

function show_word_count_column($column_name, $post_id) {
    if ($column_name === 'word_count') {
        $content = get_post_field('post_content', $post_id);
        $word_count = str_word_count(strip_tags($content));
        echo number_format($word_count);
    }
}