XBuilder - A simple tool to build complicated XML objects from nested components

x_builder.rb

require "active_support/core_ext"

class XBuilder
  attr_reader :data, :namespace, :root
  def initialize(data)
    @namespace = data.delete(:_namespace)
    @root = data.delete(:_root)
    @data = data
  end

  def to_xml(options={})
    hash = data.transform_keys do |key|
      key = key.to_s.camelize if key.is_a?(Symbol)
      key.include?(':') ? key : [namespace,key].compact.join(':')
    end
    options.merge!(root: root) if root
    hash.to_xml(options)
  end
end

An example of usage:

x = XBuilder.new(
      foo: 'bar'
    )

x1 =  XBuilder.new(
		    _root: 'ns2:X1',
		    another: 'one'
			)

x2 =  XBuilder.new(
		    _root: 'ns4:X2',
		    _namespace: :ns4,
		    and: 'another'
			)

x3 =  XBuilder.new(
			  _root: 'ns1:MyXML',
			  _namespace: :ns1,
		    from_now: 'ho',
		    'ThisID': 'kd',
		    'root' => 'ddd',
		    'name:spaced' => 'true',
		    root: 'sss',
		    x: x,
		    x1: x1,
		    y: x2
		  )

puts x3.to_xml

Produces:

<?xml version="1.0" encoding="UTF-8"?>
<ns1:MyXML>
  <ns1:FromNow>ho</ns1:FromNow>
  <ns1:ThisID>kd</ns1:ThisID>
  <ns1:root>ddd</ns1:root>
  <name:spaced>true</name:spaced>
  <ns1:Root>sss</ns1:Root>
  <ns1:X>
    <Foo>bar</Foo>
  </ns1:X>
  <ns2:X1>
    <Another>one</Another>
  </ns2:X1>
  <ns4:X2>
    <ns4:And>another</ns4:And>
  </ns4:X2>
</ns1:MyXML>