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# frozen_string_literal: true
require "forwardable"
require "configurate/setting_path"
require "configurate/lookup_chain"
require "configurate/provider"
require "configurate/proxy"
# A flexible and extendable configuration system.
# The calling logic is isolated from the lookup logic
# through configuration providers, whose only requirement
# is to define the +#lookup+ method and show a certain behavior on that.
# The providers are asked in the order they were added until one provides
# a response. This allows to even add multiple providers of the same type,
# you never easier defined your default configuration parameters.
# There is no shared state, you can have an unlimited amount of
# independent configuration sources at the same time.
#
# See {Settings} for a quick start.
module Configurate
# This is your main entry point. Instead of lengthy explanations
# let an example demonstrate its usage:
#
# require 'configuration_methods'
#
# AppSettings = Configurate::Settings.create do
# add_provider Configurate::Provider::Env
# add_provider Configurate::Provider::YAML, '/etc/app_settings.yml',
# namespace: Rails.env, required: false
# add_provider Configurate::Provider::YAML, 'config/default_settings.yml'
#
# extend YourConfigurationMethods
# end
#
# AppSettings.setup_something if AppSettings.something.enable?
#
# Please also read the note at {Proxy}!
class Settings
attr_reader :lookup_chain
undef_method :method # Remove possible conflicts with common setting names
extend Forwardable
def initialize
@lookup_chain = LookupChain.new
warn "Warning you called Configurate::Settings.new with a block, you really meant to call #create" if block_given?
end
# @!method lookup(setting)
# (see {LookupChain#lookup})
# @!method add_provider(provider, *args)
# (see {LookupChain#add_provider})
# @!method [](setting)
# (see {LookupChain#[]})
def_delegators :@lookup_chain, :lookup, :add_provider, :[]
# rubocop:disable Style/MethodMissingSuper we handle all calls
# rubocop:disable Style/MissingRespondToMissing we override respond_to? instead
# See description and {#lookup}, {#[]} and {#add_provider}
def method_missing(method, *args, &block)
Proxy.new(@lookup_chain).public_send(method, *args, &block)
end
# rubocop:enable all
# Create a new configuration object
# @yield the given block will be evaluated in the context of the new object
def self.create(&block)
config = new
config.instance_eval(&block) if block_given?
config
end
end
# This is supposed to be raised by providers if the requested setting
# does not exist, (remember, nil is a valid value and thus rarely a sufficient check)
# and this should be communicated to the end user.
class MissingSetting < RuntimeError; end
# This is supposed to be raised by providers if the requested setting
# cannot be found and the next provider in the chain should be tried.
class SettingNotFoundError < RuntimeError; end
end
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