rails-model-patterns

Rails Model Patterns

Analyze and recommend ActiveRecord model patterns for well-structured Rails applications.

Resolve the axis first

Where a model's domain logic and side effects belong forks on Axis A — logic placement:

1. If the axes are resolved this session, use them.
2. Otherwise resolve via rails-stack-profiles (Axis A — native or extracted).
3. Then read the matching decomposition guide:
   • native → decomposition.native.md
   • extracted → decomposition.extracted.md

Default to native if the axis cannot be resolved. Everything else in this file is invariant.

Supporting Documentation

• associations.md - Association decision guidance and advanced patterns
• validations.md - Validation strategy and custom validators
• migrations.md - Safe migration practices for production
• value-objects.md - Value object and Struct/Data patterns
• decomposition.native.md / decomposition.extracted.md - where domain logic and side effects go, per Axis A

Core Principles

1. Organize by convention: Constants, associations, validations, scopes, callbacks, class methods, instance methods
2. Database-backed integrity: Always pair ActiveRecord validations with database constraints (unique index, NOT NULL, check constraints)
3. Associations always have :dependent: Prevent orphaned records
4. Use :inverse_of: Ensure bidirectional association consistency
5. Callbacks: Posture depends on Axis A — read the decomposition guide above. Universally: a callback is for one predictable effect, never multi-step orchestration.

Model Structure Template

Follow standard Rails model organization. Key ordering: constants, associations, validations, scopes, callbacks, class methods, instance methods, private methods. Generate standard ActiveRecord associations, validations, and scopes following Rails conventions.