Meta Boxes in WordPress

WordPress Plugin Development Series (35/95). Prefer one article? Read the complete WordPress plugin development tutorial.

Short description

Register meta boxes, render fields, and save on `save_post` with nonce + capability checks.

Meta box sketch

add_action('add_meta_boxes', function () {
    add_meta_box('acme_book', 'Book Details', 'acme_book_box', 'book');
});

add_action('save_post_book', function ($post_id) {
    if (! isset($_POST['acme_book_nonce']) || ! wp_verify_nonce(sanitize_text_field(wp_unslash($_POST['acme_book_nonce'])), 'acme_book_save')) {
        return;
    }
    // save fields...
});