WordPress plugin development

Create a custom database table in a WordPress plugin with dbDelta wp_postmeta stores any key-value data, but for high-volume or relational plugin data (logs, statistics, bookings) it becomes a bottleneck: every value is a LONGTEXT in one huge table, and filtering by several values means several joins. A custom table gives you your own columns…

Verify nonces and sanitize input in WordPress AJAX handlers AJAX requests in WordPress go to admin-ajax.php, which any visitor can call. So every handler must check where the request comes from and what it contains. A CSRF attack makes the browser of a logged-in user send a forged request to your site; a nonce, a…

Use wp_add_dashboard_widget() to register custom panels on the WordPress admin dashboard that display site stats, quick links, or any custom content.

Build a secure WordPress plugin options page using register_setting, add_settings_section and add_settings_field with sanitise callbacks.

Register a custom meta box on WordPress posts and pages with wp_nonce_field CSRF protection and sanitised save_post handling.

Add custom sort options and price range filtering to WooCommerce shop pages using woocommerce_catalog_orderby filter and pre_get_posts.

wp_parse_args(): merge arguments with defaults Functions with many options take one $args array instead of a long list of parameters: WP_Query, wp_nav_menu(), wp_list_comments() all work that way. The caller passes only what differs from the defaults, and inside the function wp_parse_args() fills in the rest. Your own functions, shortcodes and widgets can use the same…

Build a reliable WordPress plugin migration system with dbDelta, version options and ordered migration functions that run automatically on update.

Display success, warning and error admin notices in WordPress with persistent AJAX dismissal stored in user meta.