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Diffstat (limited to 'activerecord/lib/active_record/type/value.rb')
-rw-r--r-- | activerecord/lib/active_record/type/value.rb | 101 |
1 files changed, 101 insertions, 0 deletions
diff --git a/activerecord/lib/active_record/type/value.rb b/activerecord/lib/active_record/type/value.rb new file mode 100644 index 0000000000..9456a4a56c --- /dev/null +++ b/activerecord/lib/active_record/type/value.rb @@ -0,0 +1,101 @@ +module ActiveRecord + module Type + class Value # :nodoc: + attr_reader :precision, :scale, :limit + + # Valid options are +precision+, +scale+, and +limit+. They are only + # used when dumping schema. + def initialize(options = {}) + options.assert_valid_keys(:precision, :scale, :limit) + @precision = options[:precision] + @scale = options[:scale] + @limit = options[:limit] + end + + # The simplified type that this object represents. Returns a symbol such + # as +:string+ or +:integer+ + def type; end + + # Type casts a string from the database into the appropriate ruby type. + # Classes which do not need separate type casting behavior for database + # and user provided values should override +cast_value+ instead. + def type_cast_from_database(value) + type_cast(value) + end + + # Type casts a value from user input (e.g. from a setter). This value may + # be a string from the form builder, or an already type cast value + # provided manually to a setter. + # + # Classes which do not need separate type casting behavior for database + # and user provided values should override +type_cast+ or +cast_value+ + # instead. + def type_cast_from_user(value) + type_cast(value) + end + + # Cast a value from the ruby type to a type that the database knows how + # to understand. The returned value from this method should be a + # +String+, +Numeric+, +Date+, +Time+, +Symbol+, +true+, +false+, or + # +nil+ + def type_cast_for_database(value) + value + end + + # Type cast a value for schema dumping. This method is private, as we are + # hoping to remove it entirely. + def type_cast_for_schema(value) # :nodoc: + value.inspect + end + + # These predicates are not documented, as I need to look further into + # their use, and see if they can be removed entirely. + def number? # :nodoc: + false + end + + def binary? # :nodoc: + false + end + + def klass # :nodoc: + end + + # Determines whether a value has changed for dirty checking. +old_value+ + # and +new_value+ will always be type-cast. Types should not need to + # override this method. + def changed?(old_value, new_value, _new_value_before_type_cast) + old_value != new_value + end + + # Determines whether the mutable value has been modified since it was + # read. Returns +false+ by default. This method should not be overridden + # directly. Types which return a mutable value should include + # +Type::Mutable+, which will define this method. + def changed_in_place?(*) + false + end + + def ==(other) + self.class == other.class && + precision == other.precision && + scale == other.scale && + limit == other.limit + end + + private + + def type_cast(value) + cast_value(value) unless value.nil? + end + + # Convenience method for types which do not need separate type casting + # behavior for user and database inputs. Called by + # `type_cast_from_database` and `type_cast_from_user` for all values + # except `nil`. + def cast_value(value) # :doc: + value + end + end + end +end |