Define your own Extended Metadata Type with SEEDs File

 ExtendedMetadataAttribute.new(

    # The attribute's identifier or name (mandatory) .
    title: 'title', 
    
    # Indicates whether this attribute is mandatory for the associated metadata. By default, it is set to false. 
    required: true, 
    
    # Specifies the attribute type, here set to 'String' (mandatory).
    sample_attribute_type: SampleAttributeType.where(title: 'String').first,
    
    # A brief description providing additional details about the attribute. By default, it is set to the empty string. 
    description: 'the title of your study', 
    
    # The label to be displayed in the user interface, conveying the purpose of the attribute. By default, it is set to the value of the 'title' attribute."
    label: 'study title' 
    
)

 ExtendedMetadataAttribute.new(title: 'description', required:true, sample_attribute_type: SampleAttributeType.where(title:'Text').first)

 ExtendedMetadataAttribute.new(title: 'study_start_date', required:true, sample_attribute_type: SampleAttributeType.where(title:'Date').first)

 ExtendedMetadataAttribute.new(title: 'study_start_time', required:true, sample_attribute_type: SampleAttributeType.where(title:'Date time').first)

 ExtendedMetadataAttribute.new(title: 'study_age', required:true, sample_attribute_type: SampleAttributeType.where(title:'Integer').first)

 ExtendedMetadataAttribute.new(title: 'cholesterol_level', required:true, sample_attribute_type: SampleAttributeType.where(title:'Real number').first)

 ExtendedMetadataAttribute.new(title: 'resource_use_rights_authors_confirmation', required:true, sample_attribute_type: SampleAttributeType.where(title:'Boolean').first)

def create_sample_controlled_vocab_terms_attributes(array)
  attributes = []
  array.each do |type|
    attributes << { label: type }
  end
  attributes
end


# Create a list of controlled vocablary for the personal title of role name

 role_name_personal_title_cv = SampleControlledVocab.where(title: 'Personal Title').first_or_create!(sample_controlled_vocab_terms_attributes: create_sample_controlled_vocab_terms_attributes(['Mr.', 'Ms.', 'Dr.', 'Prof. Dr.', 'Other']))
 
 ExtendedMetadataAttribute.new(title: 'role_name_personal_title', required:true,
                                                                  sample_attribute_type: SampleAttributeType.where(title:'Controlled Vocabulary').first, sample_controlled_vocab: role_name_personal_title_cv)
    

# Create a controlled vocabulary for European study countries.

    study_country_cv = SampleControlledVocab.where(title: 'study_country').first_or_create!(
    sample_controlled_vocab_terms_attributes: create_sample_controlled_vocab_terms_attributes([
      'Albania',
      'Austria',
      'Belgium',
      'Bosnia and Herzegovina',
      'Bulgaria',
      'Croatia',
      'Cyprus',
      'Czech Republic','Denmark',
      'Estonia',
      ....
    ]))

 ExtendedMetadataAttribute.new(title: 'study_country', required:true, sample_attribute_type: SampleAttributeType.where(title:'Controlled Vocabulary List').first, sample_controlled_vocab: study_country_cv)

# Define the inner extended metadata type 'person' with attributes 'first_name' and 'last_name'.
# The 'supported_type' is set to 'ExtendedMetadata' to denote it as the inner extended metadata type.

unless ExtendedMetadataType.where(title: 'person', supported_type: 'ExtendedMetadata').any?

  emt = ExtendedMetadataType.new(title: 'person', supported_type: 'ExtendedMetadata')
  
  # Define 'first_name' attribute as a 'String' type 
  emt.extended_metadata_attributes << ExtendedMetadataAttribute.new(
    title: 'first_name',
    sample_attribute_type: SampleAttributeType.where(title: 'String').first
  )
  
  # Define 'last_name' attribute as a 'String' type
  emt.extended_metadata_attributes << ExtendedMetadataAttribute.new(
    title: 'last_name',
    sample_attribute_type: SampleAttributeType.where(title: 'String').first
  )
  emt.save!
end

# Define the extended metadata type 'family', which contains the nested extended metadata attributes 
person_emt = ExtendedMetadataType.where(title: 'person', supported_type: 'ExtendedMetadata').first

unless ExtendedMetadataType.where(title: 'family', supported_type: 'Investigation').any?
  emt = ExtendedMetadataType.new(title: 'family', supported_type: 'Investigation')
  
  # Define 'dad' attribute for 'family' linked to the 'person' type
  emt.extended_metadata_attributes << ExtendedMetadataAttribute.new(
    title: 'dad',
    sample_attribute_type: SampleAttributeType.where(title: 'Linked Extended Metadata').first,
    linked_extended_metadata_type: person_emt
  )
  
  # Define 'mom' attribute for 'family' linked to the 'person' type
  emt.extended_metadata_attributes << ExtendedMetadataAttribute.new(
    title: 'mom',
    sample_attribute_type: SampleAttributeType.where(title: 'Linked Extended Metadata').first,
    linked_extended_metadata_type: person_emt
  )

  # Define 'child' attribute for 'family' linked to the 'person' type (multiple children allowed)
  emt.extended_metadata_attributes << ExtendedMetadataAttribute.new(
    title: 'child',
    sample_attribute_type: SampleAttributeType.where(title: 'Linked Extended Metadata (multiple)').first,
    linked_extended_metadata_type: person_emt
  )
end