gistfile1.ru

# Allows you to build a Hash in a fashion very similar to Builder. Example:
# 
#   HashBuilder.build! do |h|
#     h.name "Brent"
#     h.skillz true
#     h.location do
#       h.planet "Earth"
#     end
#   end
#
# produces:
#
#   {:name => "Brent", :skillz => true, :location => {:planet => "Earth"}}
#
class HashBuilder
  instance_methods.each { |m| undef_method m unless m =~ /(^__|^nil\?$|^send$|^object_id$)/ }
  
  def initialize
    @hash = {}
    @target = @hash
  end
  
  def self.build!
    builder = HashBuilder.new
    yield builder
    builder.to_h
  end
    
  def to_h
    @hash
  end
  
  def inspect
    to_h.inspect
  end
  
  def attr!(key, value=nil)
    if block_given?
      parent = @target
      @target = {}
      yield
      parent[key] = @target
      @target = parent
    else
      @target[key] = value
    end
    @hash
  end
  
  def method_missing(key, value=nil, &block)
    attr!(key, value, &block)
  end
end

class Hash
  unless method_defined?(:build!)
    def build!(&block)
      ::HashBuilder.build!(&block)
    end
  end
end