unknown_attributes.md

Unknown attributes

Sometimes JSON structure changes and it contains more keys than attributes defined in your StoreModel::Model class. In such cases, "unknown" attributes can be found inside the #unknown_attributes hash:

class Configuration
  include StoreModel::Model

  attribute :color, :string
end

configuration = Configuration.to_type.cast_value(color: "red", archived: true)
configuration.unknown_attributes # => { "archived" => true }

# OR

configurations = Configuration.to_array_type.cast_value([{ color: "red", archived: true }, { color: "blue", archived: false }])
configurations.map { |config| config.unknown_attributes } # => [{ "archived" => true }, { "archived" => false }]

Serialization of unknown attributes

By default StoreModel will serialize unknown attributes when you call as_json on an instance.

configuration = Configuration.to_type.cast_value(color: "red", archived: true)
configuration.as_json # => {"color": "red", "archived": true}

You can change that behavior globally by turning off serialization for unknown attributes.

StoreModel.config.serialize_unknown_attributes = false

configuration = Configuration.to_type.cast_value(color: "red", archived: true)
configuration.as_json # => {"color": "red"}

You can always pass the serialize_unknown_attributes option to the as_json method to override the globally configured behavior.

StoreModel.config.serialize_unknown_attributes = false

configuration = Configuration.to_type.cast_value(color: "red", archived: true)
configuration.as_json(serialize_unknown_attributes: true) # => {"color": "red", "archived": true}

Prior to version 2.1.1, unknown attributes are always stored in the database. However, starting from version 2.1.1, if serialize_unknown_attributes is set to false, unknown attributes will not be stored in the database.