59 lines
1.6 KiB
Ruby
59 lines
1.6 KiB
Ruby
# frozen_string_literal: true
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module EnumInheritance
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# == STI through Enum
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#
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# WARNING: Usage of STI is heavily discouraged: https://docs.gitlab.com/ee/development/database/single_table_inheritance.html
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#
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# Active Record allows definition of STI through the <tt>Base.inheritance_column</tt>. However, this stores the class
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# name as string into the record, which is heavy and unnecessary. EnumInheritance adapts ActiveRecord to use an enum
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# instead.
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#
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# Details:
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# - Correct class mapping is specified in the <tt>self.sti_type_map<\tt>, which maps the symbol of the type to
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# a fully classified class as string.
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# - If the type passed does not have an specified class, then the class will be the base class
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#
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# Example
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# class Animal
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# include EnumInheritable
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#
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# enum animal_type: {
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# dog: 1,
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# cat: 2,
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# bird: 3
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# }
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#
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# def self.inheritance_column_to_class_map = {
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# dog: 'Animals::Dog',
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# cat: 'Animals::Cat'
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# }
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#
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# def self.inheritance_column = 'animal_type'
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# end
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#
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# class Animals::Dog < Animal; end
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# class Animals::Cat < Animal; end
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extend ActiveSupport::Concern
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included do
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def self.sti_class_to_enum_map = inheritance_column_to_class_map.invert
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end
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class_methods do
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extend ::Gitlab::Utils::Override
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def inheritance_column_to_class_map = {}.freeze
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override :sti_class_for
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def sti_class_for(type_name)
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inheritance_column_to_class_map[type_name.to_sym]&.constantize || base_class
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end
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override :sti_name
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def sti_name
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sti_class_to_enum_map[name].to_s
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end
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end
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end
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