# frozen_string_literal: true
require "active_support/option_merger"
class Object
# An elegant way to factor duplication out of options passed to a series of
# method calls. Each method called in the block, with the block variable as
# the receiver, will have its options merged with the default +options+ hash
# provided. Each method called on the block variable must take an options
# hash as its final argument.
#
# Without with_options, this code contains duplication:
#
# class Account < ActiveRecord::Base
# has_many :customers, dependent: :destroy
# has_many :products, dependent: :destroy
# has_many :invoices, dependent: :destroy
# has_many :expenses, dependent: :destroy
# end
#
# Using with_options, we can remove the duplication:
#
# class Account < ActiveRecord::Base
# with_options dependent: :destroy do |assoc|
# assoc.has_many :customers
# assoc.has_many :products
# assoc.has_many :invoices
# assoc.has_many :expenses
# end
# end
#
# It can also be used with an explicit receiver:
#
# I18n.with_options locale: user.locale, scope: 'newsletter' do |i18n|
# subject i18n.t :subject
# body i18n.t :body, user_name: user.name
# end
#
# When you don't pass an explicit receiver, it executes the whole block
# in merging options context:
#
# class Account < ActiveRecord::Base
# with_options dependent: :destroy do
# has_many :customers
# has_many :products
# has_many :invoices
# has_many :expenses
# end
# end
#
# with_options can also be nested since the call is forwarded to its receiver.
#
# NOTE: Each nesting level will merge inherited defaults in addition to their own.
#
# class Post < ActiveRecord::Base
# with_options if: :persisted?, length: { minimum: 50 } do
# validates :content, if: -> { content.present? }
# end
# end
#
# The code is equivalent to:
#
# validates :content, length: { minimum: 50 }, if: -> { content.present? }
#
# Hence the inherited default for `if` key is ignored.
#
# NOTE: You cannot call class methods implicitly inside of with_options.
# You can access these methods using the class name instead:
#
# class Phone < ActiveRecord::Base
# enum phone_number_type: [home: 0, office: 1, mobile: 2]
#
# with_options presence: true do
# validates :phone_number_type, inclusion: { in: Phone.phone_number_types.keys }
# end
# end
#
def with_options(options, &block)
option_merger = ActiveSupport::OptionMerger.new(self, options)
block.arity.zero? ? option_merger.instance_eval(&block) : block.call(option_merger)
end
end