update AR/attribute_methods documentation [ci skip]

4 files changed, 36 insertions, 26 deletions

diff --git a/activerecord/lib/active_record/attribute_methods/primary_key.rb b/activerecord/lib/active_record/attribute_methods/primary_key.rb
index aa6704d5c9..0857b02c8e 100644
--- a/activerecord/lib/active_record/attribute_methods/primary_key.rb
+++ b/activerecord/lib/active_record/attribute_methods/primary_key.rb
@@ -5,28 +5,29 @@ module ActiveRecord
     module PrimaryKey
       extend ActiveSupport::Concern
 
-      # Returns this record's primary key value wrapped in an Array if one is available
+      # Returns this record's primary key value wrapped in an Array if one is
+      # available.
       def to_key
         key = self.id
         [key] if key
       end
 
-      # Returns the primary key value
+      # Returns the primary key value.
       def id
         read_attribute(self.class.primary_key)
       end
 
-      # Sets the primary key value
+      # Sets the primary key value.
       def id=(value)
         write_attribute(self.class.primary_key, value) if self.class.primary_key
       end
 
-      # Queries the primary key value
+      # Queries the primary key value.
       def id?
         query_attribute(self.class.primary_key)
       end
 
-      # Returns the primary key value before type cast
+      # Returns the primary key value before type cast.
       def id_before_type_cast
         read_attribute_before_type_cast(self.class.primary_key)
       end
@@ -52,14 +53,16 @@ module ActiveRecord
           super && !ID_ATTRIBUTE_METHODS.include?(method_name)
         end
 
-        # Defines the primary key field -- can be overridden in subclasses. Overwriting will negate any effect of the
-        # primary_key_prefix_type setting, though.
+        # Defines the primary key field -- can be overridden in subclasses.
+        # Overwriting will negate any effect of the +primary_key_prefix_type+
+        # setting, though.
         def primary_key
           @primary_key = reset_primary_key unless defined? @primary_key
           @primary_key
         end
 
-        # Returns a quoted version of the primary key name, used to construct SQL statements.
+        # Returns a quoted version of the primary key name, used to construct
+        # SQL statements.
         def quoted_primary_key
           @quoted_primary_key ||= connection.quote_column_name(primary_key)
         end
@@ -92,16 +95,17 @@ module ActiveRecord
         # Sets the name of the primary key column.
         #
         #   class Project < ActiveRecord::Base
-        #     self.primary_key = "sysid"
+        #     self.primary_key = 'sysid'
         #   end
         #
-        # You can also define the primary_key method yourself:
+        # You can also define the +primary_key+ method yourself:
         #
         #   class Project < ActiveRecord::Base
         #     def self.primary_key
-        #       "foo_" + super
+        #       'foo_' + super
         #     end
         #   end
+        #
         #   Project.primary_key # => "foo_id"
         def primary_key=(value)
           @primary_key        = value && value.to_s
diff --git a/activerecord/lib/active_record/attribute_methods/read.rb b/activerecord/lib/active_record/attribute_methods/read.rb
index 1a4cb25dd7..6213b5dcd5 100644
--- a/activerecord/lib/active_record/attribute_methods/read.rb
+++ b/activerecord/lib/active_record/attribute_methods/read.rb
@@ -14,9 +14,10 @@ module ActiveRecord
       end
 
       module ClassMethods
-        # +cache_attributes+ allows you to declare which converted attribute values should
-        # be cached. Usually caching only pays off for attributes with expensive conversion
-        # methods, like time related columns (e.g. +created_at+, +updated_at+).
+        # +cache_attributes+ allows you to declare which converted attribute
+        # values should be cached. Usually caching only pays off for attributes
+        # with expensive conversion methods, like time related columns (e.g.
+        # +created_at+, +updated_at+).
         def cache_attributes(*attribute_names)
           cached_attributes.merge attribute_names.map { |attr| attr.to_s }
         end
@@ -65,8 +66,9 @@ module ActiveRecord
 
       ActiveRecord::Model.attribute_types_cached_by_default = ATTRIBUTE_TYPES_CACHED_BY_DEFAULT
 
-      # Returns the value of the attribute identified by <tt>attr_name</tt> after it has been typecast (for example,
-      # "2004-12-12" in a data column is cast to a date object, like Date.new(2004, 12, 12)).
+      # Returns the value of the attribute identified by <tt>attr_name</tt> after
+      # it has been typecast (for example, "2004-12-12" in a data column is cast
+      # to a date object, like Date.new(2004, 12, 12)).
       def read_attribute(attr_name)
         return unless attr_name
         name_sym = attr_name.to_sym
diff --git a/activerecord/lib/active_record/attribute_methods/serialization.rb b/activerecord/lib/active_record/attribute_methods/serialization.rb
index bdda5bc009..d2cfcbbaf8 100644
--- a/activerecord/lib/active_record/attribute_methods/serialization.rb
+++ b/activerecord/lib/active_record/attribute_methods/serialization.rb
@@ -4,17 +4,19 @@ module ActiveRecord
       extend ActiveSupport::Concern
 
       included do
-        # Returns a hash of all the attributes that have been specified for serialization as
-        # keys and their class restriction as values.
+        # Returns a hash of all the attributes that have been specified for
+        # serialization as keys and their class restriction as values.
         class_attribute :serialized_attributes, instance_accessor: false
         self.serialized_attributes = {}
       end
 
       module ClassMethods
-        # If you have an attribute that needs to be saved to the database as an object, and retrieved as the same object,
-        # then specify the name of that attribute using this method and it will be handled automatically.
-        # The serialization is done through YAML. If +class_name+ is specified, the serialized object must be of that
-        # class on retrieval or SerializationTypeMismatch will be raised.
+        # If you have an attribute that needs to be saved to the database as an
+        # object, and retrieved as the same object, then specify the name of that
+        # attribute using this method and it will be handled automatically. The
+        # serialization is done through YAML. If +class_name+ is specified, the
+        # serialized object must be of that class on retrieval or
+        # <tt>SerializationTypeMismatch</tt> will be raised.
         #
         # ==== Parameters
         #
@@ -22,7 +24,8 @@ module ActiveRecord
         # * +class_name+ - Optional, class name that the object type should be equal to.
         #
         # ==== Example
-        #   # Serialize a preferences attribute
+        #
+        #   # Serialize a preferences attribute.
         #   class User < ActiveRecord::Base
         #     serialize :preferences
         #   end
@@ -60,7 +63,7 @@ module ActiveRecord
         end
       end
 
-      class Attribute < Struct.new(:coder, :value, :state)
+      class Attribute < Struct.new(:coder, :value, :state) # :nodoc:
         def unserialized_value
           state == :serialized ? unserialize : value
         end
diff --git a/activerecord/lib/active_record/attribute_methods/write.rb b/activerecord/lib/active_record/attribute_methods/write.rb
index 5a39cb0125..6eb9e25fd9 100644
--- a/activerecord/lib/active_record/attribute_methods/write.rb
+++ b/activerecord/lib/active_record/attribute_methods/write.rb
@@ -20,8 +20,9 @@ module ActiveRecord
           end
       end
 
-      # Updates the attribute identified by <tt>attr_name</tt> with the specified +value+. Empty strings
-      # for fixnum and float columns are turned into +nil+.
+      # Updates the attribute identified by <tt>attr_name</tt> with the
+      # specified +value+. Empty strings for fixnum and float columns are
+      # turned into +nil+.
       def write_attribute(attr_name, value)
         attr_name = attr_name.to_s
         attr_name = self.class.primary_key if attr_name == 'id' && self.class.primary_key