Module: NormalizeIt::ClassMethods

Defined in:
lib/normalize_it.rb

Overview

normalize_it makes it easy to seamlessly manage database tables that have been normalized.

Example:

create_table :customer_statuses, :force => true do |t| t.string :customer_status end

create_table :email_addresses, :force => true do |t| t.string :email_address end

create_table :customers, :force => true do |t| t.string :name t.integer :customer_status_id t.integer :email_address_id end

class CustomerStatus < ActiveRecord::Base normalizes :customers, :with_field => :customer_status validates :customer_status, :presence => true validates_uniqueness_of :customer_status end

class EmailAddress < ActiveRecord::Base normalizes :customers, :allow_inserts => true validates :email_address, :presence => true validates_uniqueness_of :email_address end

class Customer < ActiveRecord::Base has_normalized :customer_status has_normalized :email_address, :allow_inserts => true end

after calling normalizes:

* if :allow_inserts is false (default), a :with_field argument must be passed in
** new objects of CustomerStatus may not be created by the app
** CustomerStatus objects may be referenced by [] notation, eg CustomerStatus[:new] or CustomerStatus['new']
** CustomerStatus is given a has_many association to Customer, has_many options may be passed in to normalizes
* if :allow_inserts is true
** only the has_many association is set up
** [] notation may be used only if the :with_field option is passed

after calling has_normalized:

* if :allow_inserts is false (default)
** customer.customer_status = 'new' will only search for CustomerStatus['new'] and assign it if it is found
* if :allow_inserts is true
** customer.email_address = '[email protected]' will search for the email address, and create it if not found
* all columns on the normalized tables are delegated to the parent object. e.g. customer.email_address
* static rails-like finders may be used. e.g. Customer.find_by_email_address '[email protected]'
* new objects may be initialized either with attributes or through later assignment. e.g. Customer.new(:email_address => '[email protected]')

Instance Attribute Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#_normalized_models ⇒ Object (readonly)

Returns the value of attribute _normalized_models.



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

def _normalized_models
  @_normalized_models
end

Instance Method Details

#has_normalized(model, options = {}) ⇒ Object 



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# File 'lib/normalize_it.rb', line 65

def has_normalized(model, options = {})
  include NormalizeIt::BaseClassMethods
  @_normalized_models ||= []
  allow_inserts = options.try(:delete, :allow_inserts) || false
  opts = { :class_name  => model.to_s.camelize,
           :autosave    => true,
           :foreign_key => model.to_s.foreign_key }.merge!(options)
  belongs_to "__#{opts[:class_name].underscore}".to_sym, opts
  validates "__#{opts[:class_name].underscore}".to_sym, :presence => true
  validates_associated "__#{opts[:class_name].underscore}".to_sym
  @_normalized_models << opts.merge( { :allow_inserts => allow_inserts } )
  opts[:class_name].constantize.content_columns.each do |column|
    next if ['created_at', 'updated_at'].include?(column.name)
    delegate "#{column.name}", "#{column.name}?", :to => "__#{opts[:class_name].underscore}".to_sym
    if allow_inserts
      delegate "#{column.name}=", :to => "__#{opts[:class_name].underscore}".to_sym
    else
      self.class_eval do
        define_method "#{column.name}=" do |value|
          self.send("__#{opts[:class_name].underscore}=",
                    value.is_a?(opts[:class_name].constantize) ? value :
                                opts[:class_name].constantize[value]
                   )
        end
      end
    end
    eval "      def self.find_by_\#{column.name} value\n        self.send(\"find_by_\#{opts[:foreign_key]}\",\n                  \#{opts[:class_name]}.send(\"find_by_\#{column.name}\", value)\n                 )\n      end\n      def self.find_all_by_\#{column.name} value\n        self.send(\"find_all_by_\#{opts[:foreign_key]}\",\n                  \#{opts[:class_name]}.send(\"find_by_\#{column.name}\", value)\n                 )\n      end\n    NEWFINDERS\n  end\n\n  before_validation :handle_normalized_objects if allow_inserts\nend\n"

#normalizes(model, options = {}) ⇒ Object 



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# File 'lib/normalize_it.rb', line 108

def normalizes(model, options = {})
  include NormalizeIt::NormalizedClassMethods
  allow_inserts = options.try(:delete, :allow_inserts) || false
  if !allow_inserts
    normalized_field = options.try(:delete, :with_field)
    raise NormalizeItException, "Normalized field must be specified on static tables!" unless normalized_field
    before_create :disallow_create unless allow_inserts
    if normalized_field
      eval "        def self.[] value\n          @@\#{self.name.underscore.pluralize} ||= HashWithIndifferentAccess.new\n          @@\#{self.name.underscore.pluralize}[value] ||= find_by_\#{normalized_field.to_s}(value.to_s)\n          @@\#{self.name.underscore.pluralize}[value]\n        end\n      HASHNOTATIONACCESS\n    end\n  end\n  has_many model, options\nend\n"