Module: DslAccessor

Included in:
Class, Module
Defined in:
lib/dsl_accessor/stores.rb,
lib/dsl_accessor/version.rb,
lib/dsl_accessor/accessor.rb,
lib/dsl_accessor/auto_declare.rb

Defined Under Namespace

Modules: AutoDeclare, Stores

Constant Summary collapse

VERSION = 
"0.4.1"

Instance Method Summary collapse

Instance Method Details

#dsl_accessor(*args, &block) ⇒ Object 



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# File 'lib/dsl_accessor/accessor.rb', line 43

def dsl_accessor(*args, &block)
  opts = Optionize.new(args, :name, :default)
  name = opts.name

  if block
    case name
    when :class, NilClass
      AutoDeclare::DefineClassMethod.new(self, &block)
    when :instance
      AutoDeclare::DefineInstanceMethod.new(self, &block)
    else
      raise ArgumentError, "dsl_accessor block expects :class or :instance for arg, but got #{name.inspect}"
    end
    return
  end

  if !name
    raise ArgumentError, "dsl_accessor expects at least one arg"
  end

  writer =
    case opts.writer
    when NilClass then Proc.new{|value| value}
    when Symbol   then Proc.new{|value| __send__(opts.writer, value)}
    when Proc     then opts.writer
    else raise TypeError, "DSL Error: writer should be a symbol or proc. but got `#{opts.writer.class}'"
    end
  dsl_accessor_set("#{name}_writer", writer)

  default =
    case opts.default
    when NilClass then nil
    when []       then Proc.new{[]}
    when {}       then Proc.new{{}}
    when Symbol   then Proc.new{__send__(opts.default)}
    when Proc     then opts.default
    else Proc.new{opts.default}
    end
  dsl_accessor_set("#{name}_default", default)

  meta_class = (class << self; self; end)

  if opts.instance and !is_a?(Class)
    raise ArgumentError, ":instance option is implemented in only Class"
  end

  case opts.instance
  when nil
    # nop
  when true
    delegate name, :to=>"self.class"
  when Symbol
    module_eval(<<-EOS, "(__DSL_ACCESSOR__)", 1)
      def #{ name }
        @#{opts.instance} or
          raise TypeError, "DSL Error: missing @#{opts.instance} for %s##{name}" % self.class.name
        @#{opts.instance}.respond_to?(:[]) or
          raise TypeError, "DSL Error: expected @#{opts.instance}[] is implemented (%s##{name})" % self.class.name
        @#{opts.instance}[:#{ name }] || self.class.#{ name }
      end
    EOS
  else
    raise TypeError, "DSL Error: :instance should be true or Symbol, but got `%s' class" % opts.instance.class
  end

  instance_eval <<-EOS
    def #{name}(*args, &block)
      dsl_accessor_reader("#{name}", *args, &block)
    end
    def #{name}=(*args, &block)
      dsl_accessor_writer("#{name}", *args, &block)
    end
  EOS
end

#dsl_accessor_reader(key, *args, &block) ⇒ Object 



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# File 'lib/dsl_accessor/accessor.rb', line 4

def dsl_accessor_reader(key, *args, &block)
  key = key.to_s
  if !args.empty? or block_given?
    # setter method
    dsl_accessor_writer(key, *args, &block)
  else
    # getter method
    if !dsl_accessor_key?(key)
      # load default value
      default = dsl_accessor_get("#{key}_default")
      value   = default ? default.call : nil
      dsl_accessor_writer(key, value)
    end
    dsl_accessor_get(key)
  end
end

#dsl_accessor_writer(key, *args, &block) ⇒ Object 



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# File 'lib/dsl_accessor/accessor.rb', line 21

def dsl_accessor_writer(key, *args, &block)
  case args.size
  when 0
    unless block_given?
      raise ArgumentError, "'#{key}=' expected one argument or block, but nothing passed"
    end
    writer = dsl_accessor_get("#{key}_writer")
    value  = writer ? writer.call(block) : block
    dsl_accessor_set("#{key}", value)
  when 1
    if block_given?
      raise ArgumentError, "'#{key}=' got both arg and block, specify only one of them"
    end

    writer = dsl_accessor_get("#{key}_writer")
    value  = writer ? writer.call(*args) : args.first
    dsl_accessor_set("#{key}", value)
  else
    raise ArgumentError, "'#{key}=' expected one argument, but got #{args.size} args"
  end
end