Active Model Value Type

The base class for all attribute types. This class also serves as the default type for attributes that do not specify a type.

Methods

Included Modules

Attributes

[R] limit
[R] precision
[R] scale

Class Public methods

new(precision: nil, limit: nil, scale: nil)

Initializes a type with three basic configuration settings: precision, limit, and scale. The Value base class does not define behavior for these settings. It uses them for equality comparison and hash key generation only.

📝 Source code 
# File activemodel/lib/active_model/type/value.rb, line 17
      def initialize(precision: nil, limit: nil, scale: nil)
        super()
        @precision = precision
        @scale = scale
        @limit = limit
      end
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Instance Public methods

==(other)

Also aliased as: eql?
📝 Source code 
# File activemodel/lib/active_model/type/value.rb, line 121
      def ==(other)
        self.class == other.class &&
          precision == other.precision &&
          scale == other.scale &&
          limit == other.limit
      end
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as_json(*)

📝 Source code 
# File activemodel/lib/active_model/type/value.rb, line 144
      def as_json(*)
        raise NoMethodError
      end
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assert_valid_value(_)

📝 Source code 
# File activemodel/lib/active_model/type/value.rb, line 133
      def assert_valid_value(_)
      end
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cast(value)

Type casts a value from user input (e.g. from a setter). This value may be a string from the form builder, or a ruby object passed to a setter. There is currently no way to differentiate between which source it came from.

The return value of this method will be returned from ActiveRecord::AttributeMethods::Read#read_attribute. See also: Value#cast_value.

value The raw input, as provided to the attribute setter.

📝 Source code 
# File activemodel/lib/active_model/type/value.rb, line 57
      def cast(value)
        cast_value(value) unless value.nil?
      end
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changed?(old_value, new_value, _new_value_before_type_cast)

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.

📝 Source code 
# File activemodel/lib/active_model/type/value.rb, line 84
      def changed?(old_value, new_value, _new_value_before_type_cast)
        old_value != new_value
      end
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changed_in_place?(raw_old_value, new_value)

Determines whether the mutable value has been modified since it was read. Returns false by default. If your type returns an object which could be mutated, you should override this method. You will need to either:

or

raw_old_value The original value, before being passed to deserialize.

new_value The current value, after type casting.

📝 Source code 
# File activemodel/lib/active_model/type/value.rb, line 105
      def changed_in_place?(raw_old_value, new_value)
        false
      end
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deserialize(value)

Converts a value from database input to the appropriate ruby type. The return value of this method will be returned from ActiveRecord::AttributeMethods::Read#read_attribute. The default implementation just calls Value#cast.

value The raw input, as provided from the database.

📝 Source code 
# File activemodel/lib/active_model/type/value.rb, line 43
      def deserialize(value)
        cast(value)
      end
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eql?(other)

Alias for: ==

hash()

📝 Source code 
# File activemodel/lib/active_model/type/value.rb, line 129
      def hash
        [self.class, precision, scale, limit].hash
      end
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serializable?(value)

Returns true if this type can convert value to a type that is usable by the database. For example a boolean type can return true if the value parameter is a Ruby boolean, but may return false if the value parameter is some other object.

📝 Source code 
# File activemodel/lib/active_model/type/value.rb, line 28
      def serializable?(value)
        true
      end
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serialize(value)

Casts 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.

📝 Source code 
# File activemodel/lib/active_model/type/value.rb, line 65
      def serialize(value)
        value
      end
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type()

Returns the unique type name as a Symbol. Subclasses should override this method.

📝 Source code 
# File activemodel/lib/active_model/type/value.rb, line 34
      def type
      end
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Instance Private methods

cast_value(value)

Convenience method for types which do not need separate type casting behavior for user and database inputs. Called by Value#cast for values except nil.

📝 Source code 
# File activemodel/lib/active_model/type/value.rb, line 152
        def cast_value(value) # :doc:
          value
        end
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