Laravel Modular Architecture

laravel-modular-architecture.md

Laravel Modular Architecture

This document outlines the architectural decisions and patterns used in our Laravel-based applications. It serves as a guide for understanding how we structure our code and make architectural decisions.

Core Principles

1. Modular Design: Organize code around business domains
2. SOLID Principles: Follow software design principles for maintainable code
3. Domain-Driven Design: Structure code around business domains
4. Progressive Enhancement: Start simple, evolve as needed

Application Structure

Modular Architecture

We use a modular approach to organize our Laravel applications. Each module represents a distinct business domain and follows a consistent structure:

src/
  ModuleName/
    Console/
      Commands/
    Controllers/
    Models/
    Services/
    Routes/
      web.php
      api.php
    README.md

Module Components

• Models: Domain entities and relationships
• Controllers: HTTP request/response handling
• Services: Business logic and domain operations
• Commands: Console tasks and scheduled jobs
• Routes: Module-specific endpoints
• README.md: Module documentation

Example: Currency Exchange Module

src/
  CurrencyExchange/
    Console/
      Commands/
        DownloadCurrencyRates.php
    Models/
      CurrencyRate.php
    Services/
      CurrencyService.php
    Routes/
      api.php
    README.md

Design Patterns

Model-View-Controller (MVC)

We follow Laravel's MVC pattern:

• Models: Business logic and data access
• Views: Presentation layer (Blade templates)
• Controllers: Request handling and response generation

Service Layer

We use services to:

• Encapsulate complex business logic
• Provide reusable functionality
• Keep controllers thin
• Enable better testing

Repository Pattern

Repositories are used to:

• Abstract data access
• Provide a consistent interface
• Make testing easier
• Centralize query logic

Best Practices

Code Organization

1. Module Independence: Keep modules as independent as possible
2. Clear Interfaces: Define clear boundaries between modules
3. Shared Code: Use a common module for shared functionality
4. Documentation: Maintain README files for each module
5. Testing: Write tests at the module level

When to Create Modules

Create a new module when:

• The functionality represents a distinct business domain
• The code could be reused in other projects
• The feature set is large enough to warrant separation
• Different teams will work on different parts

Module Communication

Modules communicate through:

• Service classes
• Events and listeners
• Shared interfaces
• Message queues
• API endpoints

Development Approach

Starting Simple

We begin with a monolithic application and:

• Organize code into modules
• Keep related code together
• Maintain clear boundaries
• Make modules self-contained

Progressive Enhancement

As the application grows:

• Extract modules when needed
• Maintain clear interfaces
• Keep documentation up to date
• Consider microservices for specific domains

Testing Strategy

• Unit tests for business logic
• Feature tests for HTTP endpoints
• Integration tests for module interactions
• End-to-end tests for critical paths

Documentation

• Each module has its own README
• Architecture decisions are documented
• API documentation is maintained
• Code is self-documenting where possible

Further Reading

• Laravel Documentation
• Domain-Driven Design
• SOLID Principles
• Hexagonal Architecture