Module: MagicOptions

Defined in:

lib/magic_options.rb,
lib/magic_options/version.rb

Overview

MagicOptions is a ruby module that provides mechanisms for splatting an options hash into an object’s instance variables, typically during object initialization. Each key is taken as the name of an instance variable, to which the associated value is assigned.

For example:

<tt>

class Cow
  def initialize(name, options = {})
    @name = name.capitalize
    @color = color
    @gender = gender
  end
end

Cow.new('Daisy', :color => 'brown', :gender => 'female')
# => #<Cow:0x000000015d02b8 @color="brown", @gender="female", @name="Daisy">

</tt>

Here’s how the same object initializer might be defined with MagicOptions:

<tt>

class Cow
  include MagicOptions

  def initialize(name, options = {})
    @name = name.capitalize
    magic_options(options, :only => [:color, :gender])
  end
end

</tt>

If your initialize method does nothing other than implement the magic options pattern, you can let MagicOptions::ClassMethods#magic_initialize define it for you instead.

Defined Under Namespace

Modules: ClassMethods

Constant Summary

VERSION =

The version of the MagicOptions gem.

"1.0.1"

Class Method Summary

• .included(base) ⇒ Object

  :nodoc:.

Instance Method Summary

• #magic_options(options, config = {}) ⇒ Object

  Assign every value from the options hash into an instance variable named after the associated key.

Class Method Details

.included(base) ⇒ Object

:nodoc:

# File 'lib/magic_options.rb', line 63

def self.included(base) # :nodoc:
  base.extend(ClassMethods)
end

Instance Method Details

#magic_options(options, config = {}) ⇒ Object

Assign every value from the options hash into an instance variable named after the associated key. The optional config hash may impose constraints on this behaviour as follows:

:only

Specify the only options that are allowed. The special value :respond_to? specifies that options are allowed if they name a method on the instance.

:require

Specify options that must be passed. Options specified in :require do not also need to be specified in :only.

Raises:

ArgumentError

when :only is specified and an option is passed that is not in :only or :require

ArgumentError

when :require specifies one or more options that are not passed

# File 'lib/magic_options.rb', line 56

def magic_options(options, config = {})
  magic_options_validate(options, config)
  options.each do |option, value|
    instance_variable_set "@#{option}", value
  end
end