How do I add validations to an ActiveAttr model?

ActiveAttr doesn't include validations by default; you must include ActiveModel's Validations module separately. For example, add 'include ActiveModel::Validations' to your class and define validations as in Rails.

ActiveAttr vs ActiveModel: which should I use?

Use ActiveAttr for lightweight, modular attribute management in plain Ruby objects without full ORM overhead. Choose ActiveModel when you need comprehensive Rails integration, validations, and callbacks out of the box, especially in Rails apps.

Can I use ActiveAttr with Rails form helpers?

Yes, if you include BasicModel or Model to meet ActiveModel API requirements, ActiveAttr models can work with Rails form helpers like form_for. Ensure attributes are defined and mass assignment is handled securely.

Does ActiveAttr handle nested attributes or associations?

No, ActiveAttr focuses on individual attribute management; it doesn't support nested attributes or database associations. You'd need to implement this manually or use a full ORM like ActiveRecord.

How to set up mass assignment security without Rails?

Include MassAssignment and add a custom sanitizer or use gems like strong_parameters. The README shows examples with ActiveModel modules, but you can adapt it for standalone Ruby apps with custom logic.

ActiveAttr or Virtus for plain Ruby objects?

ActiveAttr is better for ActiveModel compatibility and modularity, while Virtus (now discontinued) focused more on data modeling with coercion. For current projects, ActiveAttr is maintained and integrates well with Rails ecosystems.

Open-Awesome

ActiveAttr

MITRuby

A Ruby gem providing ActiveModel-like functionality for plain Ruby objects, including attributes, typecasting, mass assignment, and serialization.

GitHub

1.2k stars91 forks0 contributors

What is ActiveAttr?

ActiveAttr is a Ruby gem that extends plain Ruby objects with ActiveModel-like features such as attribute definitions, typecasting, mass assignment, and serialization. It solves the problem of needing ORM-like functionality without the complexity of ActiveRecord or full ActiveModel, making it ideal for lightweight model layers in non-Rails applications or as a supplement to existing models.

Target Audience

Ruby developers building plain Ruby objects that require structured attributes, type safety, and ActiveModel compatibility, especially in non-Rails projects or when avoiding full ORM overhead.

Value Proposition

Developers choose ActiveAttr for its modularity and simplicity—it provides just the ActiveModel features needed without bloat, integrates seamlessly with Rails when desired, and offers a clean DSL for attribute management.

Overview

What ActiveModel left out

Use Cases

Best For

Adding attribute management to plain Ruby objects
Building lightweight models without ActiveRecord
Implementing type-safe attributes with automatic conversion
Enabling mass assignment with security in non-Rails apps
Creating ActiveModel-compatible models for use with Rails tools
Testing models with integrated RSpec matchers

Not Ideal For

Applications requiring full database persistence with ActiveRecord associations and queries
Rails projects already using ActiveModel extensively where ActiveAttr adds redundant overhead
Teams needing out-of-the-box validations and callbacks without additional ActiveModel includes
Scenarios where zero-dependency, minimal plain Ruby objects are preferred over gem-based solutions

Pros & Cons

Pros

Modular Design

Allows selective inclusion of only needed modules like Attributes or MassAssignment, keeping models lightweight and focused, as shown in the README's composable examples.

Type Safety

TypecastedAttributes enable automatic conversion (e.g., string to integer) with a clean DSL, reducing boilerplate code for attribute handling.

Security Integration

MassAssignment supports Rails security features like strong parameters and protected attributes, ensuring safe bulk updates in both Rails and non-Rails apps.

Rails Compatibility

Automatically configures with Rails logger and integrates with Rails tools, making it seamless for hybrid or non-Rails projects needing ActiveModel-like behavior.

Cons

Limited ActiveModel Compliance

BasicModel only meets minimum API requirements; advanced features like validations require additional ActiveModel includes, adding complexity.

Setup Verbosity

Security features need manual inclusion of multiple modules (e.g., ForbiddenAttributesProtection), which can be error-prone and increase setup time.

Ecosystem Constraints

Lacks built-in support for nested attributes or associations, forcing developers to implement these manually or rely on other gems.

Frequently Asked Questions

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