Class: MethodFound::AttributeInterceptor

Inherits:
Interceptor
  • Object
show all
Defined in:
lib/method_found/attribute_interceptor.rb

Overview

Class defining prefix, suffix and affix methods to a class for a given attribute name or set of attribute names.

Examples:

class Person < Struct.new(:attributes)
  include MethodFound::AttributeInterceptor.new
  include MethodFound::AttributeInterceptor.new(suffix: '=')
  include MethodFound::AttributeInterceptor.new(suffix: '_contrived?')
  include MethodFound::AttributeInterceptor.new(prefix: 'clear_')
  include MethodFound::AttributeInterceptor.new(prefix: 'reset_', suffix: '_to_default!')

  def initialize(attributes = {})
    super(attributes)
  end

  private

  def attribute_contrived?(attr)
    true
  end

  def clear_attribute(attr)
    send("#{attr}=", nil)
  end

  def reset_attribute_to_default!(attr)
    send("#{attr}=", 'Default Name')
  end

  def attribute(attr)
    attributes[attr]
  end

  def attribute=(attr, value)
    attributes[attr] = value
  end
end

Instance Attribute Summary

Attributes inherited from Interceptor

#matcher

Instance Method Summary collapse

Methods inherited from Interceptor

#define_method_missing

Constructor Details

#initialize(prefix: '', suffix: '') ⇒ AttributeInterceptor 



45
46
47
48
49
50
51
52
53
 
# File 'lib/method_found/attribute_interceptor.rb', line 45

def initialize(prefix: '', suffix: '')
  @regex = /\A(?:#{Regexp.escape(prefix)})(.*)(?:#{Regexp.escape(suffix)})\z/
  @method_missing_target = method_missing_target = "#{prefix}attribute#{suffix}"
  @method_name = "#{prefix}%s#{suffix}"

  super to_proc do |_, attr_name, *args, &block|
    send(method_missing_target, attr_name, *args, &block)
  end
end

Instance Method Details

#alias_attribute(new_name, old_name) ⇒ Object 



64
65
66
67
68
69
 
# File 'lib/method_found/attribute_interceptor.rb', line 64

def alias_attribute(new_name, old_name)
  handler = method_name(old_name)
  define_method method_name(new_name) do |*arguments, &block|
    send(handler, *arguments, &block)
  end
end

#define_attribute_methods(*attr_names) ⇒ Object 



55
56
57
58
59
60
61
62
 
# File 'lib/method_found/attribute_interceptor.rb', line 55

def define_attribute_methods(*attr_names)
  handler = @method_missing_target
  attr_names.each do |attr_name|
    define_method method_name(attr_name) do |*arguments, &block|
      send(handler, attr_name, *arguments, &block)
    end
  end
end

#inspect ⇒ Object 



81
82
83
 
# File 'lib/method_found/attribute_interceptor.rb', line 81

def inspect
  "<#{self.class.name}: #{@regex.inspect}>"
end

#to_proc ⇒ Object 



71
72
73
74
75
76
77
78
79
 
# File 'lib/method_found/attribute_interceptor.rb', line 71

def to_proc
  regex = @regex
  proc do |method_name|
    (matches = regex.match(method_name)) &&
      (method_name != :attributes) &&
      respond_to?(:attributes) &&
      (attributes.keys & matches.captures).first
  end
end