WordPress Pro

Key Implementation Patterns

Nonce Verification (form submissions)

// Output nonce field in form
wp_nonce_field( 'my_action', 'my_nonce' );

// Verify on submission — bail early if invalid
if ( ! isset( $_POST['my_nonce'] ) || ! wp_verify_nonce( sanitize_text_field( wp_unslash( $_POST['my_nonce'] ) ), 'my_action' ) ) {
    wp_die( esc_html__( 'Security check failed.', 'my-textdomain' ) );
}

Sanitization & Escaping

// Sanitize input (store)
$title   = sanitize_text_field( wp_unslash( $_POST['title'] ?? '' ) );
$content = wp_kses_post( wp_unslash( $_POST['content'] ?? '' ) );
$url     = esc_url_raw( wp_unslash( $_POST['url'] ?? '' ) );

// Escape output (display)
echo esc_html( $title );
echo wp_kses_post( $content );
echo '<a href="' . esc_url( $url ) . '">' . esc_html__( 'Link', 'my-textdomain' ) . '</a>';

Enqueuing Scripts & Styles

add_action( 'wp_enqueue_scripts', 'my_theme_assets' );
function my_theme_assets(): void {
    wp_enqueue_style(
        'my-theme-style',
        get_stylesheet_uri(),
        [],
        wp_get_theme()->get( 'Version' )
    );
    wp_enqueue_script(
        'my-theme-script',
        get_template_directory_uri() . '/assets/js/main.js',
        [ 'jquery' ],
        '1.0.0',
        true // load in footer
    );
    // Pass server data to JS safely
    wp_localize_script( 'my-theme-script', 'MyTheme', [
        'ajaxUrl' => admin_url( 'admin-ajax.php' ),
        'nonce'   => wp_create_nonce( 'my_ajax_nonce' ),
    ] );
}

Prepared Database Queries

global $wpdb;
$results = $wpdb->get_results(
    $wpdb->prepare(
        "SELECT * FROM {$wpdb->prefix}my_table WHERE user_id = %d AND status = %s",
        absint( $user_id ),
        sanitize_text_field( $status )
    )
);

Capability Checks

// Always check capabilities before sensitive operations
if ( ! current_user_can( 'manage_options' ) ) {
    wp_die( esc_html__( 'You do not have permission to do this.', 'my-textdomain' ) );
}

Constraints

MUST DO

• Follow WordPress Coding Standards (WPCS); validate with phpcs --standard=WordPress
• Use nonces for all form submissions and AJAX requests
• Sanitize all user inputs with appropriate functions (sanitize_text_field, wp_kses_post, etc.)
• Escape all outputs (esc_html, esc_url, esc_attr, wp_kses_post)
• Use prepared statements for all database queries ($wpdb->prepare)
• Implement proper capability checks before privileged operations
• Enqueue scripts/styles via wp_enqueue_scripts / admin_enqueue_scripts hooks
• Use WordPress hooks instead of modifying core
• Write translatable strings with text domains (__(), esc_html__(), etc.)
• Test across target WordPress versions

MUST NOT DO

• Modify WordPress core files
• Use PHP short tags or deprecated functions
• Trust user input without sanitization
• Output data without escaping
• Hardcode database table names (use $wpdb->prefix)
• Skip capability checks in admin functions
• Ignore SQL injection vectors
• Bundle unnecessary libraries when WordPress APIs suffice
• Allow unsafe file upload handling
• Skip internationalization (i18n)

Output Templates

When implementing WordPress features, provide:

1. Main plugin/theme file with proper headers
2. Relevant template files or block code
3. Functions with proper WordPress hooks
4. Security implementations (nonces, sanitization, escaping)
5. Brief explanation of WordPress-specific patterns used

Knowledge Reference

WordPress 6.4+, PHP 8.1+, Gutenberg, WooCommerce, ACF, REST API, WP-CLI, block development, theme customizer, widget API, shortcode API, transients, object caching, query optimization, security hardening, WPCS