How-To Guides

Task-oriented guides for accomplishing specific goals with JD.Domain. Each guide focuses on a single task with clear steps and working code examples.

Domain Modeling

Learn how to define your domain model:

• Define Entities - Create entity definitions with properties
• Define Value Objects - Model value objects and complex types
• Define Enums - Create enumeration types

Business Rules

Learn how to create and use business rules:

• Create Invariants - Define always-true rules
• Create Validators - Build context-dependent validation rules
• Create Policies - Implement authorization and business policies
• Create Derivations - Define computed properties
• Compose Rules - Combine and reuse multiple rules

Configuration

Learn how to configure EF Core integration:

• Configure Keys - Set up primary and composite keys
• Configure Indexes - Create unique and filtered indexes
• Configure Relationships - Define foreign keys and navigation

Integration

Learn how to integrate with frameworks:

• Apply to ModelBuilder - Integrate with EF Core DbContext
• Validate in ASP.NET - Add automatic API validation

Generators

Learn how to use source generators:

• Generate FluentValidation - Auto-generate FluentValidation validators
• Generate Domain Types - Create construction-safe domain types

Version Management

Learn how to track domain evolution:

• Create Snapshots - Save domain state at points in time
• Compare Snapshots - Detect changes between versions
• Detect Breaking Changes - Identify breaking changes automatically
• Generate Migration Plans - Create step-by-step migration guides

Tooling

Learn how to use JD.Domain tools:

• Use CLI Tools - Command-line tools for snapshots and diffs
• Use T4 Templates - Integrate with T4 for code generation

Guide Format

Each how-to guide follows this structure:

1. Goal - What you'll accomplish
2. Prerequisites - What you need before starting
3. Steps - Numbered steps with code examples
4. Result - What you should see
5. Next Steps - Related guides

Finding the Right Guide

By Task

• I want to define my domain → Domain Modeling guides
• I want to add validation → Business Rules guides
• I want to use EF Core → Configuration + Integration guides
• I want to generate code → Generator guides
• I want to track changes → Version Management guides
• I want to use command-line tools → Tooling guides

By Experience Level

Beginner:

• Define Entities
• Create Invariants
• Apply to ModelBuilder
• Use CLI Tools

Intermediate:

• Define Value Objects
• Create Validators
• Configure Indexes
• Generate FluentValidation
• Create Snapshots

Advanced:

• Define Enums
• Create Policies
• Configure Relationships
• Generate Domain Types
• Generate Migration Plans

See Also

• Tutorials - Step-by-step walkthroughs
• Concepts - Deep dives into architecture
• API Reference - Complete API documentation