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Provide a better interface for accessing configuration options stored in ENV. Keys are accepted as symbols and turned into upcased strings. Nesting is provided by double underscores.

This interface mirrors what is used for ActiveSupport::EncryptedConfiguration and thus allows both to serve as interchangeable backends for Rails.app.credentials.

Examples:

require(:db_host)                                   # => ENV.fetch("DB_HOST")
require(:database, :host)                           # => ENV.fetch("DATABASE__HOST")
option(:database, :host)                            # => ENV["DATABASE__HOST"]
option(:debug, default: "true")                     # => ENV.fetch("DB_HOST") { "true" }
option(:database, :host, default: -> { "missing" }) # => ENV.fetch("DATABASE__HOST") { default.call }
Methods
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Class Public methods

new()

# File activesupport/lib/active_support/env_configuration.rb, line 20
def initialize
  reload
end

Instance Public methods

option(*key, default: nil)

Find an upcased and double-underscored-joined string-version of the key in ENV. Returns nil if the key isn’t found or the value of default when passed. If default is a callable, it’s called first.

Examples:

option(:db_host)                                    # => ENV["DB_HOST"]
option(:database, :host)                            # => ENV["DATABASE__HOST"]
option(:database, :host, default: "missing")        # => ENV.fetch("DATABASE__HOST", "missing")
option(:database, :host, default: -> { "missing" }) # => ENV.fetch("DATABASE__HOST") { default.call }
# File activesupport/lib/active_support/env_configuration.rb, line 45
def option(*key, default: nil)
  if default.respond_to?(:call)
    @envs.fetch(envify(*key)) { default.call }
  else
    @envs.fetch envify(*key), default
  end
end

reload()

Reload the cached ENV values in case any of them changed or new ones were added during runtime.

# File activesupport/lib/active_support/env_configuration.rb, line 54
def reload
  @envs = ENV.to_h
end

require(*key)

Find an upcased and double-underscored-joined string-version of the key in ENV. Raises KeyError if not found.

Examples:

require(:db_host)         # => ENV.fetch("DB_HOST")
require(:database, :host) # => ENV.fetch("DATABASE__HOST")
# File activesupport/lib/active_support/env_configuration.rb, line 31
def require(*key)
  @envs.fetch envify(*key)
end