Difference between betting_system and betting_system_web in Elixir

In an Elixir Phoenix application that uses LiveView and follows the Umbrella Project structure, you often have two separate apps:

1. lib/betting_system/ (Core Logic - Contexts)
2. lib/betting_system_web/ (Web Interface - Web Layer)

🔍 lib/betting_system/ (Core Logic)

This directory is where you define your domain logic and business rules. It typically contains:

• Contexts: Modules that interact with your database and handle business operations.
• Schemas: Database schemas that define your data structure (like Ecto.Schema modules).
• Services: Any core services not related to web delivery.
• Business Logic: Everything not tied to the web layer directly.

Example structure:

lib/betting_system/
├── betting_system.ex      # Entry point defining your application supervision tree
├── accounts               # Example context (User management, authentication, etc.)
│   ├── accounts.ex
│   └── user.ex
├── betting                # Another context (Managing bets, games, etc.)
│   ├── betting.ex
│   └── game.ex
└── repo.ex                # Ecto Repo definition for database interactions

🔍 lib/betting_system_web/ (Web Interface)

This directory is where your web-related code lives. It handles HTTP requests, LiveView rendering, controllers, views, and templates. It includes:

• LiveView Modules: Components that handle live, real-time user interfaces.
• Controllers: Handle incoming requests and map them to the appropriate contexts.
• Views & Templates: Render HTML pages.
• Routing: Defines how requests are mapped to controllers or LiveView modules.

Example structure:

lib/betting_system_web/
├── betting_system_web.ex       # Web interface entry point
├── controllers                 # Standard Phoenix controllers
│   ├── page_controller.ex
│   └── user_controller.ex
├── live                        # LiveView modules
│   ├── user_live.ex
│   └── betting_live.ex
├── templates                   # HTML templates
│   ├── layout.html.heex
│   └── user
├── router.ex                   # Routes for HTTP and LiveView requests
└── endpoint.ex                 # Configures and starts the web interface

✅ Key Differences

📌 Why This Separation?

• Separation of Concerns: Keeps business logic separate from presentation logic.
• Testability: Easier to test core logic without involving web interface.
• Reusability: The core logic (lib/betting_system/) can be used independently of the web interface.