Settings
Basic usage
dry-system provides a :settings provider source that you can use to load settings and share them throughout your application. To use this provider source, create your own :settings provider using the provider source from :dry_system, then declare your settings inside settings block (using dry-configurable’s setting API):
# system/providers/settings.rb:
require "dry/system"
require "dry/system/provider_sources"
Application.register_provider(:settings, from: :dry_system) do
before :prepare do
# Change this to load your own `Types` module if you want type-checked settings
require "your/types/module"
end
settings do
setting :database_url, constructor: Types::String.constrained(filled: true)
setting :logger_level, default: :info, constructor: Types::Symbol
.constructor { |value| value.to_s.downcase.to_sym }
.enum(:trace, :unknown, :error, :fatal, :warn, :info, :debug)
end
end
Your provider will then map ENV variables to a struct object giving access to your settings as their own methods, which you can use throughout your application:
Application[:settings].database_url # => "postgres://..."
Application[:settings].logger_level # => :info
You can use this settings object in other providers:
Application.register_provider(:redis) do
start do
uri = URI.parse(target[:settings].redis_url)
redis = Redis.new(host: uri.host, port: uri.port, password: uri.password)
register('persistance.redis', redis)
end
end
Or as an injected dependency in your classes:
module Operations
class CreateUser
include Import[:settings]
def call(params)
settings # => your settings struct
end
end
end
end