📝 GDS Form WebApp - MVD Requirements

This project is a multi-page annual return form system built using Spring Boot, Thymeleaf, and HTMX. It supports dynamic form flows, year-specific validations, and server-driven UI updates with minimal JavaScript(I hate it)

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✅ Minimum Viable Design (MVD)

🎯 Core Functional Requirements

• Multi-page form (10+ pages)
• Conditional navigation (next page based on user input)
• Supports various field types using GDS style
• Auto-save form state (session-based or temporary storage)
• Progress tracking (progress menu or breadcrumbs)
• Resume saved forms from session (?)

🌟 Extended Features (Future Enhancements)

These features are planned for development after the MVD milestone is complete.

🗓 Version Handling

• Supports form logic changes based on version/year (e.g., 2024 vs 2025)
• Versioned page wording and validations using .property files(English and Welsh)
• Store version metadata with each form

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🧾 Input & Validation

• Per-field validation (client and server)
• Year-specific validation using Strategy/Factory pattern
• Inline error display using HTMX partials
• File upload validation (type/size restrictions)

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🖥️ Frontend (Thymeleaf + HTMX)

Templates

• Thymeleaf templates per page (e.g., page1.html, page2.html)
• Shared layout template (layout.html) or extends
• Reusable Thymeleaf fragments for inputs, footers, headers or blocks.

HTMX Interactivity

• Field-level validation without page reload
• Load next/previous pages without full reload
• Show/hide fields dynamically based on user input
• Update dropdowns/sections live via backend logic( Country list)

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🧱 Backend (Spring Boot)

Controllers

• Abstract base controller with shared page logic
• Year-specific page controllers
• File upload handler with multipart support

Services

• Validator Strategy per year/page
• Validator Factory to return appropriate logic
• FormFlowEngine to handle navigation logic

Models

• Unified AnnualReturnForm model or per-page POJOs
• Use of @ModelAttribute, @Validated, and BindingResult

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🔐 Security & UX

• CSRF protection enabled (Spring default)
• Session expiration handling
• Back-button and reload-friendly navigation
• Basic error handling (404, 500 pages)
• Responsive design (mobile-first)

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🧪 Testing

• Unit tests for page validators
• Integration tests for form flow logic
• Manual browser-based testing of flows and validations or Selenium testing 🧪

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🔮 Future Enhancements (Post-MVD)

• 🔁 Multi-user authentication with Spring Security and JWT
• 💾 Database persistence layer
• 📄 PDF export of completed return
• ⚙️ Admin UI for managing wording, validation rules, and FE components
• • 🧠 AI support with common FAQ

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🏗 Tech Stack

• Java 21+
• Spring Boot 3
• Thymeleaf
• HTMX
• Gradle

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