Architecture

Architecture

The plugin follows a class-based structure with separate files for each major feature area.

File & Folder Structure

caswell-booking/
  caswell-booking.php         Main plugin file, bootstrap, helpers, encryption
  page-caswell-home.php       Custom home page template

  includes/
    class-admin.php           Admin settings page, sanitization, validation
    class-auth.php            User registration, login, forgot/reset password, email verification
    class-booking-db.php      Database layer (bookings, series, blocks)
    class-booking-handler.php AJAX handlers for booking flow, cancellation, Square payments, refunds
    class-cron.php            WP-Cron reminder scheduling (per-booking + hourly sweep)
    class-google-calendar.php Google Calendar API (OAuth2, fetch events, create/delete events, availability)
    class-notifications.php   Email + SMS (Twilio) for confirmations, reminders, cancellations
    class-recurring.php       Recurring series generation and creation

  public/
    booking-shortcode.php     [caswell_booking] shortcode — multi-step booking form
    account-shortcode.php     [caswell_account] shortcode — login/register/manage bookings
    js/booking.js             Front-end JavaScript for booking widget + account widget
    css/booking.css           All public-facing styles

  admin/
    admin-page.php            Settings page template with tabs

  templates/
    email-confirmation.php    HTML email template for booking confirmation
    email-reminder.php        HTML email template for appointment reminder
    sms-confirmation.php      SMS confirmation template
    sms-reminder.php          SMS reminder template

Key Classes

Class	File	Responsibility
Caswell_Admin	includes/class-admin.php	Admin settings UI, sanitization, validation
Caswell_Auth	includes/class-auth.php	Authentication — registration, login, password reset, email verification
Caswell_Booking_DB	includes/class-booking-db.php	Database-Schema — CRUD for bookings, series, and blocks
Caswell_Booking_Handler	includes/class-booking-handler.php	AJAX-Endpoints — booking flow, cancellation, Payments
Caswell_Cron	includes/class-cron.php	Scheduling — WP-Cron reminders
Caswell_Google_Calendar	includes/class-google-calendar.php	Google-Calendar — OAuth2, availability
Caswell_Notifications	includes/class-notifications.php	Notifications — email and SMS
Caswell_Recurring	includes/class-recurring.php	Scheduling — recurring series logic

Entry Point

caswell-booking.php is the main plugin file. It bootstraps the plugin by loading all class files, registering shortcodes, enqueuing scripts/styles, and providing global helper functions including the encryption utilities (see Admin-Settings).