Module: HasMetaData::ClassMethods

Defined in:
lib/has_meta_data.rb

Instance Method Summary collapse

Instance Method Details

#has_meta_data(options = {}, &block) ⇒ Object 



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# File 'lib/has_meta_data.rb', line 7

def has_meta_data(options = {}, &block)
  return if self.included_modules.include?(HasMetaData::InstanceMethods)
  include HasMetaData::InstanceMethods
  
  cattr_accessor :meta_data_class_name, :meta_data_foreign_key, :meta_data_table_name, :meta_data_columns
  
  self.meta_data_class_name = options[:class_name]  || 'Meta'
  self.meta_data_foreign_key = options[:foreign_key] || self.to_s.foreign_key
  self.meta_data_table_name = options[:table_name]  || "#{table_name_prefix}#{self.name.demodulize.underscore}_meta#{table_name_suffix}"
  
  
  # Create Relationship to Meta Data
  class_eval do
    has_one :meta, 
      :class_name => "#{self.to_s}::#{meta_data_class_name}",
      :foreign_key => meta_data_foreign_key,
      :dependent => :destroy
    
    scope :with_meta, lambda { includes(:meta).where("#{meta_data_table_name}.id IS NOT NULL") }
    scope :without_meta, lambda { includes(:meta).where("#{meta_data_table_name}.id IS NULL") }
  end
  
  # Dynamically Create Model::Meta Class
  const_set(meta_data_class_name, Class.new(ActiveRecord::Base))
  
  meta_data_class.cattr_accessor :original_class
  meta_data_class.original_class = self
  meta_data_class.table_name = meta_data_table_name
  
  # Draft Parent Association
  meta_data_class.belongs_to self.to_s.demodulize.underscore.to_sym, :class_name => "::#{self.to_s}", :foreign_key => meta_data_foreign_key
  
  # Block extension
  meta_data_class.class_eval(&block) if block_given?
  
  # Finally setup attribute delegation to the meta fields
  self.meta_data_columns = meta_data_class.content_columns.map(&:name)
  
  meta_data_columns.each do |field|
    define_method(field.to_sym) do
      meta.send(field.to_sym) if has_meta_data?
    end
    
    define_method("#{field}=".to_sym) do |value|
      self.build_meta unless has_meta_data?
      meta.send("#{field}=".to_sym, value)
    end
  end
end

#meta_data_class ⇒ Object 



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# File 'lib/has_meta_data.rb', line 57

def meta_data_class
  const_get(meta_data_class_name)
end