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Features

Features are the core building blocks of Featury. Each feature represents an individual feature flag that can be enabled, disabled, or checked for status.

Defining Features

Use the feature method to define a feature flag:

class BillingFeature < ApplicationFeature
  prefix :billing

  feature :api
  feature :webhooks
  feature :invoicing
end

This creates three feature flags:

  • :billing_api
  • :billing_webhooks
  • :billing_invoicing

Feature Naming with Prefixes

The prefix method defines a namespace for all features in the class:

class PaymentSystemFeature < ApplicationFeature
  prefix :payment_system

  feature :api      # => :payment_system_api
  feature :webhooks # => :payment_system_webhooks
end

Naming Conventions

  • Prefixes should use underscores: user_onboarding, payment_system
  • Feature names should be concise: api, webhooks, passage
  • Combined names use single underscores: :user_onboarding_passage

Feature Descriptions

Add descriptions to document what each feature does:

class BillingFeature < ApplicationFeature
  prefix :billing

  feature :api, description: "External billing API integration"
  feature :webhooks, description: "Webhook endpoints for billing events"
  feature :invoicing, description: "Automated invoice generation"
end

Descriptions are preserved and accessible via the .info method:

BillingFeature.info.features.all
# => [
#      { name: :billing_api, description: "External billing API integration" },
#      { name: :billing_webhooks, description: "Webhook endpoints for billing events" },
#      { name: :billing_invoicing, description: "Automated invoice generation" }
#    ]

Multiple Features in One Class

You can define multiple related features in a single class:

class User::AccountFeature < ApplicationFeature
  prefix :user_account

  resource :user, type: User, option: true

  feature :profile_editing, description: "Allow users to edit their profiles"
  feature :avatar_upload, description: "Allow users to upload avatars"
  feature :email_change, description: "Allow users to change their email"
  feature :password_reset, description: "Enable password reset functionality"
end

When you call actions on this class, they will operate on all four features:

User::AccountFeature.enabled?(user: user)
# Checks if ALL four features are enabled for this user

User::AccountFeature.enable(user: user)
# Enables ALL four features for this user

Feature Aggregation Logic

By default, Featury uses all-must-match logic:

class ApplicationFeature < Featury::Base
  action :enabled?, web: :enabled? do |features:, **options|
    features.all? { |feature| Flipper.enabled?(feature, *options.values) }
    # Returns true only if ALL features are enabled
  end

  action :disabled?, web: :regular do |features:, **options|
    features.any? { |feature| !Flipper.enabled?(feature, *options.values) }
  end

  action :enable, web: :enable do |features:, **options|
    features.all? { |feature| Flipper.enable(feature, *options.values) }
  end

  action :disable, web: :disable do |features:, **options|
    features.all? { |feature| Flipper.disable(feature, *options.values) }
  end

  action :add, web: :regular do |features:, **options|
    features.all? { |feature| Flipper.add(feature, *options.values) }
  end
end

You can customize this behavior in your action definitions. See Actions for details.

Working with Individual Features

To work with individual features, create separate classes:

class BillingAPIFeature < ApplicationFeature
  prefix :billing

  feature :api, description: "Billing API"
end

class BillingWebhooksFeature < ApplicationFeature
  prefix :billing

  feature :webhooks, description: "Billing webhooks"
end

# Now you can control them independently
BillingAPIFeature.enable(user: user)
BillingWebhooksFeature.disable(user: user)

Or use your feature flag system directly for granular control:

Flipper.enable(:billing_api, user)
Flipper.disable(:billing_webhooks, user)

Feature Tree

Access all features including nested groups via .info.tree:

class MainFeature < ApplicationFeature
  prefix :main

  feature :alpha
  feature :beta

  group SubFeature, description: "Sub-features"
end

class SubFeature < ApplicationFeature
  prefix :sub

  feature :gamma
end

MainFeature.info.tree.features
# Direct features: [:main_alpha, :main_beta]

MainFeature.info.tree.groups
# Features from nested groups: [:sub_gamma]

See Info and Introspection for complete details on the info API.

Next Steps

  • Learn about Groups for organizing features hierarchically
  • Add Resources for type-safe parameters
  • Define Conditions for conditional feature activation
  • See Examples for real-world feature definitions