Advanced features

XPath querying and node mapping

Nokogiri, Oga, REXML, LibXML

Moxml provides efficient XPath querying by leveraging the native XML library’s implementation while maintaining consistent node mapping:

# Find all book elements
books = doc.xpath('//book')
# Returns Moxml::Element objects mapped to native nodes

# Find with namespaces
titles = doc.xpath('//dc:title',
  'dc' => 'http://purl.org/dc/elements/1.1/')

# Find first matching node
first_book = doc.at_xpath('//book')

# Chain queries
doc.xpath('//book').each do |book|
  # Each book is a mapped Moxml::Element
  title = book.at_xpath('.//title')
  puts "#{book['id']}: #{title.text}"
end

Ox

The native Ox’s query method locate resembles XPath but has a different syntax.

HeadedOx

HeadedOx provides comprehensive (but not fully) XPath 1.0 support via a pure Ruby XPath engine layered on top of Ox.

Namespace handling

# Add namespace to element
element.add_namespace('dc', 'http://purl.org/dc/elements/1.1/')

# Create element in namespace
title = doc.create_element('dc:title')
title.text = 'Document Title'

# Query with namespaces
doc.xpath('//dc:title',
  'dc' => 'http://purl.org/dc/elements/1.1/')

Accessing native implementation

While not typically needed, you can access the underlying XML library’s nodes:

# Get native node
native_node = element.native

# Get adapter being used
adapter = element.context.config.adapter

# Create from native node
element = Moxml::Element.new(native_node, context)