Instance serialization

General

Instances of Lutaml::Model::Serializable can be serialized to various formats using the to_{format} methods, including to_xml, to_yaml, to_json, to_toml, etc.

The instance serialization method to_{format} accepts various options for the tailoring of output.

Skipping model attributes (`except:` option)

In to_{format}, the except option allows you to exclude certain model attributes from being included in the output.

except: An array of attribute names.

class JapaneseCeramic < Lutaml::Model::Serializable
  attribute :glaze_type, :string
  attribute :description, :string

  xml do
    root 'JapaneseCeramic'
    map_attribute 'glazeType', to: :glaze_type
    map_element 'description', to: :description
  end
end

# Create a new instance
> instance = JapaneseCeramic.new(glaze_type: "Clear", description: "Porcelain")
#=> #<JapaneseCeramic:0x00000002e5625650 @description="Porcelain", @glaze_type="Clear">

# Serialize the instance to XML without glaze_type
> instance.to_xml(except: [:glaze_type])
#=> "<JapaneseCeramic>\n  <description>Porcelain</description>\n</JapaneseCeramic>"

# Serialize the instance to XML without glaze_type and description
> instance.to_xml(except: [:glaze_type, :description])
#=> "<JapaneseCeramic/>"

# Serialize the instance to YAML without glaze_type
> instance.to_yaml(except: [:glaze_type])
#=> "---\ndescription: Porcelain\n"

# Serialize the instance to YAML without glaze_type and description
> instance.to_yaml(except: [:glaze_type, :description])
#=> "--- {}\n"

Character encoding (`encoding:` option)

The encoding: option is used to customize the character encoding of the serialized content.

Please refer to [xml-instance-character-encoding] for details.

Namespace prefix handling (`prefix:` option)

The prefix: option is used to customize namespace prefix behavior for the serialized XML content.

Values

The prefix option accepts the following values:

Value Behavior

Value	Behavior
(not specified), `nil`, or `false`	Use default namespace (`xmlns="…"`) with no prefix. This is the default behavior.
`true`	Use the namespace’s `prefix_default` from XmlNamespace class
`String`	Use the provided custom prefix string

(not specified), nil, or false

Use default namespace (xmlns="…") with no prefix. This is the default behavior.

true

Use the namespace’s prefix_default from XmlNamespace class

String

Use the provided custom prefix string

Examples

Using namespace’s default prefix:

model.to_xml(prefix: true)
# Uses prefix_default from namespace class

Using custom prefix:

model.to_xml(prefix: "custom")
# Uses "custom" as the prefix

Documentation

For comprehensive coverage of namespace prefix customization including inheritance and semantic vs presentation distinction, see: Custom Namespace Prefixes.