Module: ActiveSupport::CoreExtensions::Array::Conversions

Included in:
Array
Defined in:
lib/active_support/core_ext/array/conversions.rb

Instance Method Summary collapse

Instance Method Details

#to_xml(options = {}) ⇒ Object

Returns a string that represents this array in XML by sending to_xml to each element. Active Record collections delegate their representation in XML to this method.

All elements are expected to respond to to_xml, if any of them does not an exception is raised.

The root node reflects the class name of the first element in plural if all elements belong to the same type and that’s not Hash:

customer.projects.to_xml

<?xml version="1.0" encoding="UTF-8"?>
<projects type="array">
  <project>
    <amount type="decimal">20000.0</amount>
    <customer-id type="integer">1567</customer-id>
    <deal-date type="date">2008-04-09</deal-date>
    ...
  </project>
  <project>
    <amount type="decimal">57230.0</amount>
    <customer-id type="integer">1567</customer-id>
    <deal-date type="date">2008-04-15</deal-date>
    ...
  </project>
</projects>

Otherwise the root element is “records”:

[{:foo => 1, :bar => 2}, {:baz => 3}].to_xml

<?xml version="1.0" encoding="UTF-8"?>
<records type="array">
  <record>
    <bar type="integer">2</bar>
    <foo type="integer">1</foo>
  </record>
  <record>
    <baz type="integer">3</baz>
  </record>
</records>

If the collection is empty the root element is “nil-classes” by default:

[].to_xml

<?xml version="1.0" encoding="UTF-8"?>
<nil-classes type="array"/>

To ensure a meaningful root element use the :root option:

customer_with_no_projects.projects.to_xml(:root => "projects")

<?xml version="1.0" encoding="UTF-8"?>
<projects type="array"/>

By default root children have as node name the one of the root singularized. You can change it with the :children option.

The options hash is passed downwards:

Message.all.to_xml(:skip_types => true)

<?xml version="1.0" encoding="UTF-8"?>
<messages>
  <message>
    <created-at>2008-03-07T09:58:18+01:00</created-at>
    <id>1</id>
    <name>1</name>
    <updated-at>2008-03-07T09:58:18+01:00</updated-at>
    <user-id>1</user-id>
  </message>
</messages>



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# File 'lib/active_support/core_ext/array/conversions.rb', line 83

def to_xml(options = {})
  raise "Not all elements respond to to_xml" unless all? { |e| e.respond_to? :to_xml }

  options[:root]     ||= all? { |e| e.is_a?(first.class) && first.class.to_s != "Hash" } ? first.class.to_s.underscore.pluralize : "objects"
  options[:children] ||= options[:root].singularize
  options[:indent]   ||= 2
  options[:builder]  ||= Builder::XmlMarkup.new(:indent => options[:indent])

  root     = options.delete(:root).to_s
  children = options.delete(:children)

  if !options.has_key?(:dasherize) || options[:dasherize]
    root = root.dasherize
  end

  options[:builder].instruct! unless options.delete(:skip_instruct)

  opts = options.merge({ :root => children })

  xml = options[:builder]
  if empty?
    xml.tag!(root, options[:skip_types] ? {} : {:type => "array"})
  else
    xml.tag!(root, options[:skip_types] ? {} : {:type => "array"}) {
      yield xml if block_given?
      each { |e| e.to_xml(opts.merge({ :skip_instruct => true })) }
    }
  end
end