Basic model definition

Introduction

This tutorial will show you how to define your first Lutaml::Model. A model represents a class of information with attributes and types.

Creating a simple model

There are two ways to define a model:

Inheriting from Lutaml::Model::Serializable
Including the Lutaml::Model::Serialize module

Through inheritance (recommended)

The simplest way is to create a class that inherits from Lutaml::Model::Serializable.

require 'lutaml/model'

class Kiln < Lutaml::Model::Serializable
  attribute :brand, :string
  attribute :capacity, :integer
  attribute :temperature, :integer
end

Through inclusion

If your class already has a superclass, use the module instead:

require 'lutaml/model'

class Kiln < SomeSuperClass
  include Lutaml::Model::Serialize

  attribute :brand, :string
  attribute :capacity, :integer
  attribute :temperature, :integer
end

Defining attributes

Attributes are defined using the attribute method:

Syntax:

attribute :name_of_attribute, Type

Where,

name_of_attribute: The name of the attribute
Type: The type (:string, :integer, :float, :boolean, :date, etc.)

Example 1. Defining a model with various attribute types

class Studio < Lutaml::Model::Serializable
  attribute :name, :string
  attribute :address, :string
  attribute :established, :date
end

s = Studio.new(
  name: 'Pottery Studio',
  address: '123 Clay St',
  established: Date.new(2020, 1, 1)
)

puts s.name
#=> "Pottery Studio"
puts s.established
#=> <Date: 2020-01-01>

Using your model

Once defined, you can create instances and access attributes:

kiln = Kiln.new(
  brand: 'CeramicPro',
  capacity: 100,
  temperature: 1050
)

puts kiln.brand
#=> "CeramicPro"
puts kiln.capacity
#=> 100

Adding serialization

To serialize your model, add format-specific mappings:

Example 2. Adding XML and JSON serialization

class Kiln < Lutaml::Model::Serializable
  attribute :brand, :string
  attribute :capacity, :integer
  attribute :temperature, :integer

  xml do
    root 'kiln'
    map_element 'brand', to: :brand
    map_element 'capacity', to: :capacity
    map_element 'temperature', to: :temperature
  end

  json do
    map 'brand', to: :brand
    map 'capacity', to: :capacity
    map 'temperature', to: :temperature
  end
end

kiln = Kiln.new(brand: 'CeramicPro', capacity: 100, temperature: 1050)

puts kiln.to_xml
# => <kiln>
#      <brand>CeramicPro</brand>
#      <capacity>100</capacity>
#      <temperature>1050</temperature>
#    </kiln>

puts kiln.to_json
# => {"brand":"CeramicPro","capacity":100,"temperature":1050}

Next steps

Now that you can define basic models, explore: