Merge pull request #6743 from steveklabnik/remove_composed_of

Removing composed_of

10 files changed, 9 insertions, 343 deletions

diff --git a/activerecord/lib/active_record.rb b/activerecord/lib/active_record.rb
index 8526e224da..a894d83ea7 100644
--- a/activerecord/lib/active_record.rb
+++ b/activerecord/lib/active_record.rb
@@ -36,7 +36,6 @@ module ActiveRecord
     autoload :ConnectionNotEstablished, 'active_record/errors'
     autoload :ConnectionAdapters, 'active_record/connection_adapters/abstract_adapter'
 
-    autoload :Aggregations
     autoload :Associations
     autoload :AttributeMethods
     autoload :AttributeAssignment
diff --git a/activerecord/lib/active_record/aggregations.rb b/activerecord/lib/active_record/aggregations.rb
deleted file mode 100644
index 3ae7030caa..0000000000
--- a/activerecord/lib/active_record/aggregations.rb
+++ /dev/null
@@ -1,261 +0,0 @@
-module ActiveRecord
-  # = Active Record Aggregations
-  module Aggregations # :nodoc:
-    extend ActiveSupport::Concern
-
-    def clear_aggregation_cache #:nodoc:
-      @aggregation_cache.clear if persisted?
-    end
-
-    # Active Record implements aggregation through a macro-like class method called +composed_of+
-    # for representing attributes  as value objects. It expresses relationships like "Account [is]
-    # composed of Money [among other things]" or "Person [is] composed of [an] address". Each call
-    # to the macro adds a description of how the value objects are created from the attributes of
-    # the entity object (when the entity is initialized either as a new object or from finding an
-    # existing object) and how it can be turned back into attributes (when the entity is saved to
-    # the database).
-    #
-    #   class Customer < ActiveRecord::Base
-    #     composed_of :balance, :class_name => "Money", :mapping => %w(balance amount)
-    #     composed_of :address, :mapping => [ %w(address_street street), %w(address_city city) ]
-    #   end
-    #
-    # The customer class now has the following methods to manipulate the value objects:
-    # * <tt>Customer#balance, Customer#balance=(money)</tt>
-    # * <tt>Customer#address, Customer#address=(address)</tt>
-    #
-    # These methods will operate with value objects like the ones described below:
-    #
-    #  class Money
-    #    include Comparable
-    #    attr_reader :amount, :currency
-    #    EXCHANGE_RATES = { "USD_TO_DKK" => 6 }
-    #
-    #    def initialize(amount, currency = "USD")
-    #      @amount, @currency = amount, currency
-    #    end
-    #
-    #    def exchange_to(other_currency)
-    #      exchanged_amount = (amount * EXCHANGE_RATES["#{currency}_TO_#{other_currency}"]).floor
-    #      Money.new(exchanged_amount, other_currency)
-    #    end
-    #
-    #    def ==(other_money)
-    #      amount == other_money.amount && currency == other_money.currency
-    #    end
-    #
-    #    def <=>(other_money)
-    #      if currency == other_money.currency
-    #        amount <=> other_money.amount
-    #      else
-    #        amount <=> other_money.exchange_to(currency).amount
-    #      end
-    #    end
-    #  end
-    #
-    #  class Address
-    #    attr_reader :street, :city
-    #    def initialize(street, city)
-    #      @street, @city = street, city
-    #    end
-    #
-    #    def close_to?(other_address)
-    #      city == other_address.city
-    #    end
-    #
-    #    def ==(other_address)
-    #      city == other_address.city && street == other_address.street
-    #    end
-    #  end
-    #
-    # Now it's possible to access attributes from the database through the value objects instead. If
-    # you choose to name the composition the same as the attribute's name, it will be the only way to
-    # access that attribute. That's the case with our +balance+ attribute. You interact with the value
-    # objects just like you would with any other attribute:
-    #
-    #   customer.balance = Money.new(20)     # sets the Money value object and the attribute
-    #   customer.balance                     # => Money value object
-    #   customer.balance.exchange_to("DKK")  # => Money.new(120, "DKK")
-    #   customer.balance > Money.new(10)     # => true
-    #   customer.balance == Money.new(20)    # => true
-    #   customer.balance < Money.new(5)      # => false
-    #
-    # Value objects can also be composed of multiple attributes, such as the case of Address. The order
-    # of the mappings will determine the order of the parameters.
-    #
-    #   customer.address_street = "Hyancintvej"
-    #   customer.address_city   = "Copenhagen"
-    #   customer.address        # => Address.new("Hyancintvej", "Copenhagen")
-    #
-    #   customer.address_street = "Vesterbrogade"
-    #   customer.address        # => Address.new("Hyancintvej", "Copenhagen")
-    #   customer.clear_aggregation_cache
-    #   customer.address        # => Address.new("Vesterbrogade", "Copenhagen")
-    #
-    #   customer.address = Address.new("May Street", "Chicago")
-    #   customer.address_street # => "May Street"
-    #   customer.address_city   # => "Chicago"
-    #
-    # == Writing value objects
-    #
-    # Value objects are immutable and interchangeable objects that represent a given value, such as
-    # a Money object representing $5. Two Money objects both representing $5 should be equal (through
-    # methods such as <tt>==</tt> and <tt><=></tt> from Comparable if ranking makes sense). This is
-    # unlike entity objects where equality is determined by identity. An entity class such as Customer can
-    # easily have two different objects that both have an address on Hyancintvej. Entity identity is
-    # determined by object or relational unique identifiers (such as primary keys). Normal
-    # ActiveRecord::Base classes are entity objects.
-    #
-    # It's also important to treat the value objects as immutable. Don't allow the Money object to have
-    # its amount changed after creation. Create a new Money object with the new value instead. The
-    # Money#exchange_to method is an example of this. It returns a new value object instead of changing
-    # its own values. Active Record won't persist value objects that have been changed through means
-    # other than the writer method.
-    #
-    # The immutable requirement is enforced by Active Record by freezing any object assigned as a value
-    # object. Attempting to change it afterwards will result in a ActiveSupport::FrozenObjectError.
-    #
-    # Read more about value objects on http://c2.com/cgi/wiki?ValueObject and on the dangers of not
-    # keeping value objects immutable on http://c2.com/cgi/wiki?ValueObjectsShouldBeImmutable
-    #
-    # == Custom constructors and converters
-    #
-    # By default value objects are initialized by calling the <tt>new</tt> constructor of the value
-    # class passing each of the mapped attributes, in the order specified by the <tt>:mapping</tt>
-    # option, as arguments. If the value class doesn't support this convention then +composed_of+ allows
-    # a custom constructor to be specified.
-    #
-    # When a new value is assigned to the value object, the default assumption is that the new value
-    # is an instance of the value class. Specifying a custom converter allows the new value to be automatically
-    # converted to an instance of value class if necessary.
-    #
-    # For example, the NetworkResource model has +network_address+ and +cidr_range+ attributes that
-    # should be aggregated using the NetAddr::CIDR value class (http://netaddr.rubyforge.org). The constructor
-    # for the value class is called +create+ and it expects a CIDR address string as a parameter. New
-    # values can be assigned to the value object using either another NetAddr::CIDR object, a string
-    # or an array. The <tt>:constructor</tt> and <tt>:converter</tt> options can be used to meet
-    # these requirements:
-    #
-    #   class NetworkResource < ActiveRecord::Base
-    #     composed_of :cidr,
-    #                 :class_name => 'NetAddr::CIDR',
-    #                 :mapping => [ %w(network_address network), %w(cidr_range bits) ],
-    #                 :allow_nil => true,
-    #                 :constructor => Proc.new { |network_address, cidr_range| NetAddr::CIDR.create("#{network_address}/#{cidr_range}") },
-    #                 :converter => Proc.new { |value| NetAddr::CIDR.create(value.is_a?(Array) ? value.join('/') : value) }
-    #   end
-    #
-    #   # This calls the :constructor
-    #   network_resource = NetworkResource.new(:network_address => '192.168.0.1', :cidr_range => 24)
-    #
-    #   # These assignments will both use the :converter
-    #   network_resource.cidr = [ '192.168.2.1', 8 ]
-    #   network_resource.cidr = '192.168.0.1/24'
-    #
-    #   # This assignment won't use the :converter as the value is already an instance of the value class
-    #   network_resource.cidr = NetAddr::CIDR.create('192.168.2.1/8')
-    #
-    #   # Saving and then reloading will use the :constructor on reload
-    #   network_resource.save
-    #   network_resource.reload
-    #
-    # == Finding records by a value object
-    #
-    # Once a +composed_of+ relationship is specified for a model, records can be loaded from the database
-    # by specifying an instance of the value object in the conditions hash. The following example
-    # finds all customers with +balance_amount+ equal to 20 and +balance_currency+ equal to "USD":
-    #
-    #   Customer.where(:balance => Money.new(20, "USD")).all
-    #
-    module ClassMethods
-      # Adds reader and writer methods for manipulating a value object:
-      # <tt>composed_of :address</tt> adds <tt>address</tt> and <tt>address=(new_address)</tt> methods.
-      #
-      # Options are:
-      # * <tt>:class_name</tt> - Specifies the class name of the association. Use it only if that name
-      #   can't be inferred from the part id. So <tt>composed_of :address</tt> will by default be linked
-      #   to the Address class, but if the real class name is CompanyAddress, you'll have to specify it
-      #   with this option.
-      # * <tt>:mapping</tt> - Specifies the mapping of entity attributes to attributes of the value
-      #   object. Each mapping is represented as an array where the first item is the name of the
-      #   entity attribute and the second item is the name of the attribute in the value object. The
-      #   order in which mappings are defined determines the order in which attributes are sent to the
-      #   value class constructor.
-      # * <tt>:allow_nil</tt> - Specifies that the value object will not be instantiated when all mapped
-      #   attributes are +nil+. Setting the value object to +nil+ has the effect of writing +nil+ to all
-      #   mapped attributes.
-      #   This defaults to +false+.
-      # * <tt>:constructor</tt> - A symbol specifying the name of the constructor method or a Proc that
-      #   is called to initialize the value object. The constructor is passed all of the mapped attributes,
-      #   in the order that they are defined in the <tt>:mapping option</tt>, as arguments and uses them
-      #   to instantiate a <tt>:class_name</tt> object.
-      #   The default is <tt>:new</tt>.
-      # * <tt>:converter</tt> - A symbol specifying the name of a class method of <tt>:class_name</tt>
-      #   or a Proc that is called when a new value is assigned to the value object. The converter is
-      #   passed the single value that is used in the assignment and is only called if the new value is
-      #   not an instance of <tt>:class_name</tt>. If <tt>:allow_nil</tt> is set to true, the converter
-      #   can return nil to skip the assignment.
-      #
-      # Option examples:
-      #   composed_of :temperature, :mapping => %w(reading celsius)
-      #   composed_of :balance, :class_name => "Money", :mapping => %w(balance amount),
-      #                         :converter => Proc.new { |balance| balance.to_money }
-      #   composed_of :address, :mapping => [ %w(address_street street), %w(address_city city) ]
-      #   composed_of :gps_location
-      #   composed_of :gps_location, :allow_nil => true
-      #   composed_of :ip_address,
-      #               :class_name => 'IPAddr',
-      #               :mapping => %w(ip to_i),
-      #               :constructor => Proc.new { |ip| IPAddr.new(ip, Socket::AF_INET) },
-      #               :converter => Proc.new { |ip| ip.is_a?(Integer) ? IPAddr.new(ip, Socket::AF_INET) : IPAddr.new(ip.to_s) }
-      #
-      def composed_of(part_id, options = {})
-        options.assert_valid_keys(:class_name, :mapping, :allow_nil, :constructor, :converter)
-
-        name        = part_id.id2name
-        class_name  = options[:class_name]  || name.camelize
-        mapping     = options[:mapping]     || [ name, name ]
-        mapping     = [ mapping ] unless mapping.first.is_a?(Array)
-        allow_nil   = options[:allow_nil]   || false
-        constructor = options[:constructor] || :new
-        converter   = options[:converter]
-
-        reader_method(name, class_name, mapping, allow_nil, constructor)
-        writer_method(name, class_name, mapping, allow_nil, converter)
-
-        create_reflection(:composed_of, part_id, options, self)
-      end
-
-      private
-        def reader_method(name, class_name, mapping, allow_nil, constructor)
-          define_method(name) do
-            if @aggregation_cache[name].nil? && (!allow_nil || mapping.any? {|pair| !read_attribute(pair.first).nil? })
-              attrs = mapping.collect {|pair| read_attribute(pair.first)}
-              object = constructor.respond_to?(:call) ?
-                constructor.call(*attrs) :
-                class_name.constantize.send(constructor, *attrs)
-              @aggregation_cache[name] = object
-            end
-            @aggregation_cache[name]
-          end
-        end
-
-        def writer_method(name, class_name, mapping, allow_nil, converter)
-          define_method("#{name}=") do |part|
-            klass = class_name.constantize
-            unless part.is_a?(klass) || converter.nil? || part.nil?
-              part = converter.respond_to?(:call) ? converter.call(part) : klass.send(converter, part)
-            end
-
-            if part.nil? && allow_nil
-              mapping.each { |pair| self[pair.first] = nil }
-              @aggregation_cache[name] = nil
-            else
-              mapping.each { |pair| self[pair.first] = part.send(pair.last) }
-              @aggregation_cache[name] = part.freeze
-            end
-          end
-        end
-    end
-  end
-end
diff --git a/activerecord/lib/active_record/attribute_assignment.rb b/activerecord/lib/active_record/attribute_assignment.rb
index df4de8ac35..ab6d253ef8 100644
--- a/activerecord/lib/active_record/attribute_assignment.rb
+++ b/activerecord/lib/active_record/attribute_assignment.rb
@@ -132,7 +132,7 @@ module ActiveRecord
     private
 
     # Instantiates objects for all attribute classes that needs more than one constructor parameter. This is done
-    # by calling new on the column type or aggregation type (through composed_of) object with these parameters.
+    # by calling new on the column type or aggregation type object with these parameters.
     # So having the pairs written_on(1) = "2004", written_on(2) = "6", written_on(3) = "24", will instantiate
     # written_on (a date type) with Date.new("2004", "6", "24"). You can also specify a typecast character in the
     # parentheses to have the parameters typecasted before they're used in the constructor. Use i for Fixnum,
@@ -167,7 +167,7 @@ module ActiveRecord
     end
 
     def read_value_from_parameter(name, values_hash_from_param)
-      klass = (self.class.reflect_on_aggregation(name.to_sym) || column_for_attribute(name)).klass
+      klass = column_for_attribute(name).klass
       if values_hash_from_param.values.all?{|v|v.nil?}
         nil
       elsif klass == Time
diff --git a/activerecord/lib/active_record/core.rb b/activerecord/lib/active_record/core.rb
index f5d60d11b6..90f156456e 100644
--- a/activerecord/lib/active_record/core.rb
+++ b/activerecord/lib/active_record/core.rb
@@ -266,7 +266,6 @@ module ActiveRecord
         @changed_attributes[attr] = orig_value if _field_changed?(attr, orig_value, @attributes[attr])
       end
 
-      @aggregation_cache = {}
       @association_cache = {}
       @attributes_cache  = {}
 
@@ -391,7 +390,6 @@ module ActiveRecord
 
       @attributes[pk] = nil unless @attributes.key?(pk)
 
-      @aggregation_cache       = {}
       @association_cache       = {}
       @attributes_cache        = {}
       @previously_changed      = {}
diff --git a/activerecord/lib/active_record/dynamic_matchers.rb b/activerecord/lib/active_record/dynamic_matchers.rb
index e278e62ce7..23aaa319d8 100644
--- a/activerecord/lib/active_record/dynamic_matchers.rb
+++ b/activerecord/lib/active_record/dynamic_matchers.rb
@@ -56,7 +56,7 @@ module ActiveRecord
       end
 
       def valid?
-        attribute_names.all? { |name| model.columns_hash[name] || model.reflect_on_aggregation(name.to_sym) }
+        attribute_names.all? { |name| model.columns_hash[name] }
       end
 
       def define
diff --git a/activerecord/lib/active_record/model.rb b/activerecord/lib/active_record/model.rb
index d51cb30ec1..7b3d926d91 100644
--- a/activerecord/lib/active_record/model.rb
+++ b/activerecord/lib/active_record/model.rb
@@ -89,7 +89,6 @@ module ActiveRecord
     include ActiveModel::SecurePassword
     include AutosaveAssociation
     include NestedAttributes
-    include Aggregations
     include Transactions
     include Reflection
     include Serialization
diff --git a/activerecord/lib/active_record/persistence.rb b/activerecord/lib/active_record/persistence.rb
index 643c3f82ad..a23597be28 100644
--- a/activerecord/lib/active_record/persistence.rb
+++ b/activerecord/lib/active_record/persistence.rb
@@ -267,7 +267,6 @@ module ActiveRecord
     # may do e.g. record.reload(:lock => true) to reload the same record with
     # an exclusive row lock.
     def reload(options = nil)
-      clear_aggregation_cache
       clear_association_cache
 
       fresh_object =
diff --git a/activerecord/lib/active_record/reflection.rb b/activerecord/lib/active_record/reflection.rb
index ec13d27323..e9a8e90538 100644
--- a/activerecord/lib/active_record/reflection.rb
+++ b/activerecord/lib/active_record/reflection.rb
@@ -17,36 +17,17 @@ module ActiveRecord
     # and creates input fields for all of the attributes depending on their type
     # and displays the associations to other objects.
     #
-    # MacroReflection class has info for AggregateReflection and AssociationReflection
-    # classes.
+    # MacroReflection class has info for the AssociationReflection
+    # class.
     module ClassMethods
       def create_reflection(macro, name, options, active_record)
-        case macro
-        when :has_many, :belongs_to, :has_one, :has_and_belongs_to_many
-          klass = options[:through] ? ThroughReflection : AssociationReflection
-          reflection = klass.new(macro, name, options, active_record)
-        when :composed_of
-          reflection = AggregateReflection.new(macro, name, options, active_record)
-        end
+        klass = options[:through] ? ThroughReflection : AssociationReflection
+        reflection = klass.new(macro, name, options, active_record)
 
         self.reflections = self.reflections.merge(name => reflection)
         reflection
       end
 
-      # Returns an array of AggregateReflection objects for all the aggregations in the class.
-      def reflect_on_all_aggregations
-        reflections.values.grep(AggregateReflection)
-      end
-
-      # Returns the AggregateReflection object for the named +aggregation+ (use the symbol).
-      #
-      #   Account.reflect_on_aggregation(:balance) # => the balance AggregateReflection
-      #
-      def reflect_on_aggregation(aggregation)
-        reflection = reflections[aggregation]
-        reflection if reflection.is_a?(AggregateReflection)
-      end
-
       # Returns an array of AssociationReflection objects for all the
       # associations in the class. If you only want to reflect on a certain
       # association type, pass in the symbol (<tt>:has_many</tt>, <tt>:has_one</tt>,
@@ -78,24 +59,20 @@ module ActiveRecord
       end
     end
 
-    # Abstract base class for AggregateReflection and AssociationReflection. Objects of
-    # AggregateReflection and AssociationReflection are returned by the Reflection::ClassMethods.
+    # Abstract base class for AssociationReflection. Objects of AssociationReflection are returned by the Reflection::ClassMethods.
     class MacroReflection
       # Returns the name of the macro.
       #
-      # <tt>composed_of :balance, :class_name => 'Money'</tt> returns <tt>:balance</tt>
       # <tt>has_many :clients</tt> returns <tt>:clients</tt>
       attr_reader :name
 
       # Returns the macro type.
       #
-      # <tt>composed_of :balance, :class_name => 'Money'</tt> returns <tt>:composed_of</tt>
       # <tt>has_many :clients</tt> returns <tt>:has_many</tt>
       attr_reader :macro
 
       # Returns the hash of options used for the macro.
       #
-      # <tt>composed_of :balance, :class_name => 'Money'</tt> returns <tt>{ :class_name => "Money" }</tt>
       # <tt>has_many :clients</tt> returns +{}+
       attr_reader :options
 
@@ -114,7 +91,6 @@ module ActiveRecord
 
       # Returns the class for the macro.
       #
-      # <tt>composed_of :balance, :class_name => 'Money'</tt> returns the Money class
       # <tt>has_many :clients</tt> returns the Client class
       def klass
         @klass ||= class_name.constantize
@@ -122,7 +98,6 @@ module ActiveRecord
 
       # Returns the class name for the macro.
       #
-      # <tt>composed_of :balance, :class_name => 'Money'</tt> returns <tt>'Money'</tt>
       # <tt>has_many :clients</tt> returns <tt>'Client'</tt>
       def class_name
         @class_name ||= (options[:class_name] || derive_class_name).to_s
@@ -148,16 +123,6 @@ module ActiveRecord
         end
     end
 
-
-    # Holds all the meta-data about an aggregation as it was specified in the
-    # Active Record class.
-    class AggregateReflection < MacroReflection #:nodoc:
-      def mapping
-        mapping = options[:mapping] || [name, name]
-        mapping.first.is_a?(Array) ? mapping : [mapping]
-      end
-    end
-
     # Holds all the meta-data about an association as it was specified in the
     # Active Record class.
     class AssociationReflection < MacroReflection #:nodoc:
diff --git a/activerecord/lib/active_record/relation/query_methods.rb b/activerecord/lib/active_record/relation/query_methods.rb
index e0bb84d55a..529ddb5e31 100644
--- a/activerecord/lib/active_record/relation/query_methods.rb
+++ b/activerecord/lib/active_record/relation/query_methods.rb
@@ -562,8 +562,7 @@ module ActiveRecord
       when String, Array
         [@klass.send(:sanitize_sql, other.empty? ? opts : ([opts] + other))]
       when Hash
-        attributes = @klass.send(:expand_hash_conditions_for_aggregates, opts)
-        PredicateBuilder.build_from_hash(table.engine, attributes, table)
+        PredicateBuilder.build_from_hash(table.engine, opts, table)
       else
         [opts]
       end
diff --git a/activerecord/lib/active_record/sanitization.rb b/activerecord/lib/active_record/sanitization.rb
index 5530be3219..46f6c283e3 100644
--- a/activerecord/lib/active_record/sanitization.rb
+++ b/activerecord/lib/active_record/sanitization.rb
@@ -43,36 +43,6 @@ module ActiveRecord
         end
       end
 
-      # Accepts a hash of SQL conditions and replaces those attributes
-      # that correspond to a +composed_of+ relationship with their expanded
-      # aggregate attribute values.
-      # Given:
-      #     class Person < ActiveRecord::Base
-      #       composed_of :address, :class_name => "Address",
-      #         :mapping => [%w(address_street street), %w(address_city city)]
-      #     end
-      # Then:
-      #     { :address => Address.new("813 abc st.", "chicago") }
-      #       # => { :address_street => "813 abc st.", :address_city => "chicago" }
-      def expand_hash_conditions_for_aggregates(attrs)
-        expanded_attrs = {}
-        attrs.each do |attr, value|
-          if aggregation = reflect_on_aggregation(attr.to_sym)
-            mapping = aggregation.mapping
-            mapping.each do |field_attr, aggregate_attr|
-              if mapping.size == 1 && !value.respond_to?(aggregate_attr)
-                expanded_attrs[field_attr] = value
-              else
-                expanded_attrs[field_attr] = value.send(aggregate_attr)
-              end
-            end
-          else
-            expanded_attrs[attr] = value
-          end
-        end
-        expanded_attrs
-      end
-
       # Sanitizes a hash of attribute/value pairs into SQL conditions for a WHERE clause.
       #   { :name => "foo'bar", :group_id => 4 }
       #     # => "name='foo''bar' and group_id= 4"
@@ -88,8 +58,6 @@ module ActiveRecord
       #   { :address => Address.new("123 abc st.", "chicago") }
       #     # => "address_street='123 abc st.' and address_city='chicago'"
       def sanitize_sql_hash_for_conditions(attrs, default_table_name = self.table_name)
-        attrs = expand_hash_conditions_for_aggregates(attrs)
-
         table = Arel::Table.new(table_name).alias(default_table_name)
         PredicateBuilder.build_from_hash(arel_engine, attrs, table).map { |b|
           connection.visitor.accept b