Add ability to read document footers

Adds a Docx::Document#footers accessor that exposes word/footer*.xml as a
Hash keyed by footer file name, mirroring the headers reading feature (#173).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Author: satoryu

lib/docx/document.rb

@@ -22,7 +22,7 @@ module Docx
   class Document
     include Docx::SimpleInspect
 
-    attr_reader :xml, :doc, :zip, :styles, :headers
+    attr_reader :xml, :doc, :zip, :styles, :headers, :footers
 
     def initialize(path_or_io, options = {})
       @replace = {}
@@ -41,6 +41,7 @@ def initialize(path_or_io, options = {})
       @doc = Nokogiri::XML(@document_xml)
       load_styles
       load_headers
+      load_footers
       yield(self) if block_given?
     ensure
       @zip.close unless @zip.nil?
@@ -210,6 +211,15 @@ def load_headers
       @headers = Hash[filename_and_contents_pairs]
     end
 
+    def load_footers
+      footer_files = @zip.glob("word/footer*.xml").map{|h| h.name}
+      filename_and_contents_pairs = footer_files.map do |file|
+        simple_file_name = file.sub(/^word\//, "").sub(/\.xml$/, "")
+        [simple_file_name, Nokogiri::XML(@zip.read(file))]
+      end
+      @footers = Hash[filename_and_contents_pairs]
+    end
+
     def load_styles
       @styles_xml = @zip.read('word/styles.xml')
       @styles = Nokogiri::XML(@styles_xml)

spec/docx/document_spec.rb

@@ -72,6 +72,18 @@
     end
   end
 
+  describe 'read footers' do
+    before do
+      @doc = Docx::Document.open(@fixtures_path + '/multi_doc.docx')
+    end
+
+    it 'can extract footers' do
+      expect(@doc.footers).to_not be_nil
+      expect(@doc.footers.keys).to eq ["footer1"]
+      expect(@doc.footers["footer1"].text).to eq "Hello from the footer."
+    end
+  end
+
   describe 'read tables' do
     before do
       @doc = Docx::Document.open(@fixtures_path + '/tables.docx')