diff options
Diffstat (limited to 'activerecord/lib/active_record/inheritance.rb')
| -rw-r--r-- | activerecord/lib/active_record/inheritance.rb | 80 |
1 files changed, 60 insertions, 20 deletions
diff --git a/activerecord/lib/active_record/inheritance.rb b/activerecord/lib/active_record/inheritance.rb index fbdaeaae51..b25057acda 100644 --- a/activerecord/lib/active_record/inheritance.rb +++ b/activerecord/lib/active_record/inheritance.rb @@ -1,3 +1,5 @@ +# frozen_string_literal: true + require "active_support/core_ext/hash/indifferent_access" module ActiveRecord @@ -30,7 +32,7 @@ module ActiveRecord # for differentiating between them or reloading the right type with find. # # Note, all the attributes for all the cases are kept in the same table. Read more: - # http://www.martinfowler.com/eaaCatalog/singleTableInheritance.html + # https://www.martinfowler.com/eaaCatalog/singleTableInheritance.html # module Inheritance extend ActiveSupport::Concern @@ -38,30 +40,32 @@ module ActiveRecord included do # Determines whether to store the full constant name including namespace when using STI. # This is true, by default. - class_attribute :store_full_sti_class, instance_writer: false - self.store_full_sti_class = true + class_attribute :store_full_sti_class, instance_writer: false, default: true end module ClassMethods # Determines if one of the attributes passed in is the inheritance column, # and if the inheritance column is attr accessible, it initializes an # instance of the given subclass instead of the base class. - def new(*args, &block) + def new(attributes = nil, &block) if abstract_class? || self == Base raise NotImplementedError, "#{self} is an abstract class and cannot be instantiated." end - attrs = args.first if has_attribute?(inheritance_column) - subclass = subclass_from_attributes(attrs) + subclass = subclass_from_attributes(attributes) + + if subclass.nil? && scope_attributes = current_scope&.scope_for_create + subclass = subclass_from_attributes(scope_attributes) + end - if subclass.nil? && base_class == self + if subclass.nil? && base_class? subclass = subclass_from_attributes(column_defaults) end end if subclass && subclass != self - subclass.new(*args, &block) + subclass.new(attributes, &block) else super end @@ -104,21 +108,53 @@ module ActiveRecord end end - # Set this to true if this is an abstract class (see <tt>abstract_class?</tt>). - # If you are using inheritance with ActiveRecord and don't want child classes - # to utilize the implied STI table name of the parent class, this will need to be true. - # For example, given the following: + # Returns whether the class is a base class. + # See #base_class for more information. + def base_class? + base_class == self + end + + # Set this to +true+ if this is an abstract class (see + # <tt>abstract_class?</tt>). + # If you are using inheritance with Active Record and don't want a class + # to be considered as part of the STI hierarchy, you must set this to + # true. + # +ApplicationRecord+, for example, is generated as an abstract class. + # + # Consider the following default behaviour: + # + # Shape = Class.new(ActiveRecord::Base) + # Polygon = Class.new(Shape) + # Square = Class.new(Polygon) # - # class SuperClass < ActiveRecord::Base + # Shape.table_name # => "shapes" + # Polygon.table_name # => "shapes" + # Square.table_name # => "shapes" + # Shape.create! # => #<Shape id: 1, type: nil> + # Polygon.create! # => #<Polygon id: 2, type: "Polygon"> + # Square.create! # => #<Square id: 3, type: "Square"> + # + # However, when using <tt>abstract_class</tt>, +Shape+ is omitted from + # the hierarchy: + # + # class Shape < ActiveRecord::Base # self.abstract_class = true # end - # class Child < SuperClass - # self.table_name = 'the_table_i_really_want' - # end + # Polygon = Class.new(Shape) + # Square = Class.new(Polygon) # + # Shape.table_name # => nil + # Polygon.table_name # => "polygons" + # Square.table_name # => "polygons" + # Shape.create! # => NotImplementedError: Shape is an abstract class and cannot be instantiated. + # Polygon.create! # => #<Polygon id: 1, type: nil> + # Square.create! # => #<Square id: 2, type: "Square"> # - # <tt>self.abstract_class = true</tt> is required to make <tt>Child<.find,.create, or any Arel method></tt> use <tt>the_table_i_really_want</tt> instead of a table called <tt>super_classes</tt> - # + # Note that in the above example, to disallow the creation of a plain + # +Polygon+, you should use <tt>validates :type, presence: true</tt>, + # instead of setting it as an abstract class. This way, +Polygon+ will + # stay in the hierarchy, and Active Record will continue to correctly + # derive the table name. attr_accessor :abstract_class # Returns whether this class is an abstract class or not. @@ -130,6 +166,10 @@ module ActiveRecord store_full_sti_class ? name : name.demodulize end + def polymorphic_name + base_class.name + end + def inherited(subclass) subclass.instance_variable_set(:@_type_candidates_cache, Concurrent::Map.new) super @@ -217,7 +257,7 @@ module ActiveRecord def subclass_from_attributes(attrs) attrs = attrs.to_h if attrs.respond_to?(:permitted?) if attrs.is_a?(Hash) - subclass_name = attrs.with_indifferent_access[inheritance_column] + subclass_name = attrs[inheritance_column] || attrs[inheritance_column.to_sym] if subclass_name.present? find_sti_class(subclass_name) @@ -246,7 +286,7 @@ module ActiveRecord def ensure_proper_type klass = self.class if klass.finder_needs_type_condition? - write_attribute(klass.inheritance_column, klass.sti_name) + _write_attribute(klass.inheritance_column, klass.sti_name) end end end |