Method: Array#to_xml

Defined in:
activesupport/lib/active_support/core_ext/array/conversions.rb

#to_xml(options = {}) ⇒ Object

Returns a string that represents the array in XML by invoking to_xml on 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 then 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
20000.0 1567 2008-04-09 ... 57230.0 1567 2008-04-15 ...

Otherwise the root element is "objects":

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

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

[].to_xml

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

customer_with_no_projects.projects.to_xml(root: 'projects')

By default name of the node for the children of root is root.singularize. You can change it with the :children option.

The options hash is passed downwards:

Message.all.to_xml(skip_types: true)
2008-03-07T09:58:18+01:00 1 1 2008-03-07T09:58:18+01:00 1 


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# File 'activesupport/lib/active_support/core_ext/array/conversions.rb', line 183

def to_xml(options = {})
  require "active_support/builder" unless defined?(Builder::XmlMarkup)

  options = options.dup
  options[:indent]  ||= 2
  options[:builder] ||= Builder::XmlMarkup.new(indent: options[:indent])
  options[:root]    ||= \
    if first.class != Hash && all?(first.class)
      underscored = ActiveSupport::Inflector.underscore(first.class.name)
      ActiveSupport::Inflector.pluralize(underscored).tr("/", "_")
    else
      "objects"
    end

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

  root = ActiveSupport::XmlMini.rename_key(options[:root].to_s, options)
  children = options.delete(:children) || root.singularize
  attributes = options[:skip_types] ? {} : { type: "array" }

  if empty?
    builder.tag!(root, attributes)
  else
    builder.tag!(root, attributes) do
      each { |value| ActiveSupport::XmlMini.to_tag(children, value, options) }
      yield builder if block_given?
    end
  end
end