loosen rails requirement

Gemfile.lock

@@ -2,8 +2,8 @@ PATH
   remote: .
   specs:
     options_model (0.0.6)
-      activemodel (~> 5.0)
-      activesupport (~> 5.0)
+      activemodel (>= 4.2, < 6.0)
+      activesupport (>= 4.2, < 6.0)
 
 GEM
   remote: https://rubygems.org/
@@ -117,4 +117,4 @@ DEPENDENCIES
   rails (~> 5.0)
 
 BUNDLED WITH
-   1.15.4
+   1.16.0

README.md

@@ -11,24 +11,25 @@ support attribute:
 
 ## Usage
 
+```ruby
 class Person < OptionsModel::Base
-  attribute :name, :string
-  attribute :age, :integer
+ attribute :name, :string
+ attribute :age, :integer
 
-  validates :name, presence: true
+ validates :name, presence: true
 end
 
 class Book < OptionsModel::Base
-  embeds_one :author, class_name: 'Person'
+ embeds_one :author, class_name: 'Person'
 
-  attribute :title,     :string
-  attribute :tags,      :string,   array:   true
-  attribute :price,     :decimal,  default: 0
-  attribute :meta,      :json,     default: {}
-  attribute :bought_at, :datetime, default: -> { Time.new } 
+ attribute :title,     :string
+ attribute :tags,      :string,   array:   true
+ attribute :price,     :decimal,  default: 0
+ attribute :bought_at, :datetime, default: -> { Time.new } 
 
-  validates :title, presence: true
+ validates :title, presence: true
 end
+```
 
 ## Installation
 Add this line to your application's Gemfile:

lib/active_model/type.rb

@@ -0,0 +1,49 @@
+# frozen_string_literal: true
+
+require "active_model/type/helpers"
+require "active_model/type/value"
+
+require "active_model/type/big_integer"
+require "active_model/type/binary"
+require "active_model/type/boolean"
+require "active_model/type/date"
+require "active_model/type/date_time"
+require "active_model/type/decimal"
+require "active_model/type/float"
+require "active_model/type/immutable_string"
+require "active_model/type/integer"
+require "active_model/type/string"
+require "active_model/type/time"
+
+require "active_model/type/registry"
+
+module ActiveModel
+  module Type
+    @registry = Registry.new
+
+    class << self
+      attr_accessor :registry # :nodoc:
+
+      # Add a new type to the registry, allowing it to be get through ActiveModel::Type#lookup
+      def register(type_name, klass = nil, **options, &block)
+        registry.register(type_name, klass, **options, &block)
+      end
+
+      def lookup(*args, **kwargs) # :nodoc:
+        registry.lookup(*args, **kwargs)
+      end
+    end
+
+    register(:big_integer, Type::BigInteger)
+    register(:binary, Type::Binary)
+    register(:boolean, Type::Boolean)
+    register(:date, Type::Date)
+    register(:datetime, Type::DateTime)
+    register(:decimal, Type::Decimal)
+    register(:float, Type::Float)
+    register(:immutable_string, Type::ImmutableString)
+    register(:integer, Type::Integer)
+    register(:string, Type::String)
+    register(:time, Type::Time)
+  end
+end

lib/active_model/type/big_integer.rb

@@ -0,0 +1,15 @@
+# frozen_string_literal: true
+
+require "active_model/type/integer"
+
+module ActiveModel
+  module Type
+    class BigInteger < Integer # :nodoc:
+      private
+
+        def max_value
+          ::Float::INFINITY
+        end
+    end
+  end
+end

lib/active_model/type/binary.rb

@@ -0,0 +1,52 @@
+# frozen_string_literal: true
+
+module ActiveModel
+  module Type
+    class Binary < Value # :nodoc:
+      def type
+        :binary
+      end
+
+      def binary?
+        true
+      end
+
+      def cast(value)
+        if value.is_a?(Data)
+          value.to_s
+        else
+          super
+        end
+      end
+
+      def serialize(value)
+        return if value.nil?
+        Data.new(super)
+      end
+
+      def changed_in_place?(raw_old_value, value)
+        old_value = deserialize(raw_old_value)
+        old_value != value
+      end
+
+      class Data # :nodoc:
+        def initialize(value)
+          @value = value.to_s
+        end
+
+        def to_s
+          @value
+        end
+        alias_method :to_str, :to_s
+
+        def hex
+          @value.unpack("H*")[0]
+        end
+
+        def ==(other)
+          other == to_s || super
+        end
+      end
+    end
+  end
+end

lib/active_model/type/boolean.rb

@@ -0,0 +1,34 @@
+# frozen_string_literal: true
+
+module ActiveModel
+  module Type
+    # == Active \Model \Type \Boolean
+    #
+    # A class that behaves like a boolean type, including rules for coercion of user input.
+    #
+    # === Coercion
+    # Values set from user input will first be coerced into the appropriate ruby type.
+    # Coercion behavior is roughly mapped to Ruby's boolean semantics.
+    #
+    # - "false", "f" , "0", +0+ or any other value in +FALSE_VALUES+ will be coerced to +false+
+    # - Empty strings are coerced to +nil+
+    # - All other values will be coerced to +true+
+    class Boolean < Value
+      FALSE_VALUES = [false, 0, "0", "f", "F", "false", "FALSE", "off", "OFF"].to_set
+
+      def type # :nodoc:
+        :boolean
+      end
+
+      private
+
+      def cast_value(value)
+        if value == ""
+          nil
+        else
+          !FALSE_VALUES.include?(value)
+        end
+      end
+    end
+  end
+end

lib/active_model/type/date.rb

@@ -0,0 +1,56 @@
+# frozen_string_literal: true
+
+module ActiveModel
+  module Type
+    class Date < Value # :nodoc:
+      include Helpers::AcceptsMultiparameterTime.new
+
+      def type
+        :date
+      end
+
+      def serialize(value)
+        cast(value)
+      end
+
+      def type_cast_for_schema(value)
+        value.to_s(:db).inspect
+      end
+
+      private
+
+      def cast_value(value)
+        if value.is_a?(::String)
+          return if value.empty?
+          fast_string_to_date(value) || fallback_string_to_date(value)
+        elsif value.respond_to?(:to_date)
+          value.to_date
+        else
+          value
+        end
+      end
+
+      ISO_DATE = /\A(\d{4})-(\d\d)-(\d\d)\z/
+      def fast_string_to_date(string)
+        if string =~ ISO_DATE
+          new_date $1.to_i, $2.to_i, $3.to_i
+        end
+      end
+
+      def fallback_string_to_date(string)
+        new_date(*::Date._parse(string, false).values_at(:year, :mon, :mday))
+      end
+
+      def new_date(year, mon, mday)
+        if year && year != 0
+          ::Date.new(year, mon, mday) rescue nil
+        end
+      end
+
+      def value_from_multiparameter_assignment(*)
+        time = super
+        time && time.to_date
+      end
+    end
+  end
+end

lib/active_model/type/date_time.rb

@@ -0,0 +1,46 @@
+# frozen_string_literal: true
+
+module ActiveModel
+  module Type
+    class DateTime < Value # :nodoc:
+      include Helpers::TimeValue
+      include Helpers::AcceptsMultiparameterTime.new(
+        defaults: { 4 => 0, 5 => 0 }
+      )
+
+      def type
+        :datetime
+      end
+
+      private
+
+      def cast_value(value)
+        return apply_seconds_precision(value) unless value.is_a?(::String)
+        return if value.empty?
+
+        fast_string_to_time(value) || fallback_string_to_time(value)
+      end
+
+      # '0.123456' -> 123456
+      # '1.123456' -> 123456
+      def microseconds(time)
+        time[:sec_fraction] ? (time[:sec_fraction] * 1_000_000).to_i : 0
+      end
+
+      def fallback_string_to_time(string)
+        time_hash = ::Date._parse(string)
+        time_hash[:sec_fraction] = microseconds(time_hash)
+
+        new_time(*time_hash.values_at(:year, :mon, :mday, :hour, :min, :sec, :sec_fraction, :offset))
+      end
+
+      def value_from_multiparameter_assignment(values_hash)
+        missing_parameter = (1..3).detect { |key| !values_hash.key?(key) }
+        if missing_parameter
+          raise ArgumentError, missing_parameter
+        end
+        super
+      end
+    end
+  end
+end

lib/active_model/type/decimal.rb

@@ -0,0 +1,70 @@
+# frozen_string_literal: true
+
+require "bigdecimal/util"
+
+module ActiveModel
+  module Type
+    class Decimal < Value # :nodoc:
+      include Helpers::Numeric
+      BIGDECIMAL_PRECISION = 18
+
+      def type
+        :decimal
+      end
+
+      def type_cast_for_schema(value)
+        value.to_s.inspect
+      end
+
+      private
+
+      def cast_value(value)
+        casted_value = \
+          case value
+          when ::Float
+            convert_float_to_big_decimal(value)
+          when ::Numeric
+            BigDecimal(value, precision || BIGDECIMAL_PRECISION)
+          when ::String
+            begin
+              value.to_d
+            rescue ArgumentError
+              BigDecimal(0)
+            end
+          else
+            if value.respond_to?(:to_d)
+              value.to_d
+            else
+              cast_value(value.to_s)
+            end
+          end
+
+        apply_scale(casted_value)
+      end
+
+      def convert_float_to_big_decimal(value)
+        if precision
+          BigDecimal(apply_scale(value), float_precision)
+        else
+          value.to_d
+        end
+      end
+
+      def float_precision
+        if precision.to_i > ::Float::DIG + 1
+          ::Float::DIG + 1
+        else
+          precision.to_i
+        end
+      end
+
+      def apply_scale(value)
+        if scale
+          value.round(scale)
+        else
+          value
+        end
+      end
+    end
+  end
+end