adding support for XML parsing and shale type mapping

.rubocop.yml

@@ -8,3 +8,4 @@ inherit_from:
 
 AllCops:
   TargetRubyVersion: 2.5
+  NewCops: enable

lib/lutaml/parser.rb

@@ -1,6 +1,7 @@
 require "lutaml/express"
 require "lutaml/uml"
 require "lutaml/xmi"
+require "lutaml/xml"
 require "lutaml/uml/lutaml_path/document_wrapper"
 require "lutaml/express/lutaml_path/document_wrapper"
 require "expressir/express/cache"
@@ -43,6 +44,8 @@ def parse_into_document
         Expressir::Express::Cache.from_file(file_list.first.path)
       when 'xmi'
         file_list.map { |file| Lutaml::XMI::Parsers::XML.parse(file) }
+      when "xml"
+        file_list.map { |file| Lutaml::Xml::Parsers::Xml.parse(file) }
       when "lutaml"
         file_list.map { |file| Lutaml::Uml::Parsers::Dsl.parse(file) }
       when "yml"
@@ -59,6 +62,10 @@ def document_wrapper(document)
         return Lutaml::Express::LutamlPath::DocumentWrapper.new(document)
       end
 
+      if parse_type == "xml"
+        return Lutaml::Xml::LutamlPath::DocumentWrapper.new(document)
+      end
+
       Lutaml::Uml::LutamlPath::DocumentWrapper.new(document)
     end
   end

lib/lutaml/xml.rb

@@ -0,0 +1,9 @@
+require "lutaml/xml/parsers/xml"
+
+require "lutaml/xml/mapper"
+require "lutaml/xml/lutaml_path/document_wrapper"
+
+require "shale"
+require "shale/adapter/nokogiri"
+
+Shale.xml_adapter = Shale::Adapter::Nokogiri

lib/lutaml/xml/lutaml_path/document_wrapper.rb

@@ -0,0 +1,45 @@
+require "lutaml/lutaml_path/document_wrapper"
+
+module Lutaml
+  module Xml
+    module LutamlPath
+      class DocumentWrapper < ::Lutaml::LutamlPath::DocumentWrapper
+        protected
+
+        def serialize_document(document)
+          serialize_to_hash(document)
+        end
+
+        def serialize_to_hash(object)
+          hash = {}
+          attribute_name = nil
+
+          object.all_content.each do |mapping, content|
+            if mapping == "content"
+              attribute_name = object.class.xml_mapping.content.attribute.to_s
+              hash[attribute_name] ||= []
+              hash[attribute_name] << content.strip unless content.strip&.empty?
+            elsif content.is_a?(String)
+              if object.class.attributes[mapping.attribute].collection?
+                hash[mapping.name] ||= []
+                hash[mapping.name] << content.strip
+              else
+                hash[mapping.name] = content.strip
+              end
+            else
+              if object.class.attributes[mapping.attribute].collection?
+                hash[mapping.name] ||= []
+                hash[mapping.name] << serialize_to_hash(content)
+              else
+                hash[mapping.name] = serialize_to_hash(content)
+              end
+            end
+          end
+
+          hash[attribute_name] = hash[attribute_name].compact if attribute_name
+          hash
+        end
+      end
+    end
+  end
+end