diff options
Diffstat (limited to 'activerecord/lib/active_record/attribute_methods/serialization.rb')
| -rw-r--r-- | activerecord/lib/active_record/attribute_methods/serialization.rb | 43 |
1 files changed, 33 insertions, 10 deletions
diff --git a/activerecord/lib/active_record/attribute_methods/serialization.rb b/activerecord/lib/active_record/attribute_methods/serialization.rb index e03bf5945d..6e0e90f39c 100644 --- a/activerecord/lib/active_record/attribute_methods/serialization.rb +++ b/activerecord/lib/active_record/attribute_methods/serialization.rb @@ -1,23 +1,35 @@ +# frozen_string_literal: true + module ActiveRecord module AttributeMethods module Serialization extend ActiveSupport::Concern + class ColumnNotSerializableError < StandardError + def initialize(name, type) + super <<~EOS + Column `#{name}` of type #{type.class} does not support `serialize` feature. + Usually it means that you are trying to use `serialize` + on a column that already implements serialization natively. + EOS + end + 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 assignment and retrieval. - # Otherwise <tt>SerializationTypeMismatch</tt> will be raised. + # Otherwise SerializationTypeMismatch will be raised. # - # Empty objects as +{}+, in the case of +Hash+, or +[]+, in the case of + # Empty objects as <tt>{}</tt>, in the case of +Hash+, or <tt>[]</tt>, in the case of # +Array+, will always be persisted as null. # # Keep in mind that database adapters handle certain serialization tasks # for you. For instance: +json+ and +jsonb+ types in PostgreSQL will be # converted between JSON object/array syntax and Ruby +Hash+ or +Array+ - # objects transparently. There is no need to use +serialize+ in this + # objects transparently. There is no need to use #serialize in this # case. # # For more complex cases, such as conversion to or from your application @@ -26,7 +38,7 @@ module ActiveRecord # ==== Parameters # # * +attr_name+ - The field name that should be serialized. - # * +class_name_or_coder+ - Optional, a coder object, which responds to `.load` / `.dump` + # * +class_name_or_coder+ - Optional, a coder object, which responds to +.load+ and +.dump+ # or a class name that the object type should be equal to. # # ==== Example @@ -50,17 +62,28 @@ module ActiveRecord # to ensure special objects (e.g. Active Record models) are dumped correctly # using the #as_json hook. coder = if class_name_or_coder == ::JSON - Coders::JSON - elsif [:load, :dump].all? { |x| class_name_or_coder.respond_to?(x) } - class_name_or_coder - else - Coders::YAMLColumn.new(class_name_or_coder) - end + Coders::JSON + elsif [:load, :dump].all? { |x| class_name_or_coder.respond_to?(x) } + class_name_or_coder + else + Coders::YAMLColumn.new(attr_name, class_name_or_coder) + end decorate_attribute_type(attr_name, :serialize) do |type| + if type_incompatible_with_serialize?(type, class_name_or_coder) + raise ColumnNotSerializableError.new(attr_name, type) + end + Type::Serialized.new(type, coder) end end + + private + + def type_incompatible_with_serialize?(type, class_name) + type.is_a?(ActiveRecord::Type::Json) && class_name == ::JSON || + type.respond_to?(:type_cast_array, true) && class_name == ::Array + end end end end |