Add image extracting from xlsx files

lib/roo/excelx.rb

@@ -24,8 +24,9 @@ class Excelx < Roo::Base
     require 'roo/excelx/sheet_doc'
     require 'roo/excelx/coordinate'
     require 'roo/excelx/format'
+    require 'roo/excelx/images'
 
-    delegate [:styles, :workbook, :shared_strings, :rels_files, :sheet_files, :comments_files] => :@shared
+    delegate [:styles, :workbook, :shared_strings, :rels_files, :sheet_files, :comments_files, :image_rels, :image_files] => :@shared
     ExceedsMaxError = Class.new(StandardError)
 
     # initialization and opening of a spreadsheet file
@@ -97,6 +98,11 @@ def sheet_for(sheet)
       @sheets_by_name[sheet]
     end
 
+    def images(sheet = nil)
+      images_names = sheet_for(sheet).images.map(&:last)
+      images_names.map { |iname| image_files.find { |ifile| ifile[iname] } }
+    end
+
     # Returns the content of a spreadsheet-cell.
     # (1,1) is the upper left corner.
     # (1,1), (1,'A'), ('A',1), ('a',1) all refers to the
@@ -376,6 +382,15 @@ def extract_sheets_in_order(entries, sheet_ids, sheets, tmpdir)
       end
     end
 
+    def extract_images(entries, tmpdir)
+      img_entries = entries.select { |e| e.name[/media\/image([0-9]+)/] }
+      img_entries.each do |entry|
+        path = "#{@tmpdir}/roo#{entry.name.gsub(/xl\/|\//, "_")}"
+        image_files << path
+        entry.extract(path)
+      end
+    end
+
     # Extracts all needed files from the zip file
     def process_zipfile(zipfilename_or_stream)
       @sheet_files = []
@@ -409,6 +424,7 @@ def process_zipfile_entries(entries)
       sheet_ids = extract_worksheet_ids(entries, "#{@tmpdir}/roo_workbook.xml")
       sheets = extract_worksheet_rels(entries, "#{@tmpdir}/roo_workbook.xml.rels")
       extract_sheets_in_order(entries, sheet_ids, sheets, @tmpdir)
+      extract_images(entries, @tmpdir)
 
       entries.each do |entry|
         path =
@@ -435,6 +451,10 @@ def process_zipfile_entries(entries)
           #        drawings, etc.
           nr = Regexp.last_match[1].to_i
           rels_files[nr - 1] = "#{@tmpdir}/roo_rels#{nr}"
+        when /drawing([0-9]+).xml.rels$/
+          # Extracting drawing relationships to make images lists for each sheet
+          nr = Regexp.last_match[1].to_i
+          image_rels[nr -1] = "#{@tmpdir}/roo_image_rels#{nr}"
         end
 
         entry.extract(path) if path

lib/roo/excelx/images.rb

@@ -0,0 +1,26 @@
+require 'roo/excelx/extractor'
+
+module Roo
+  class Excelx
+    class Images < Excelx::Extractor
+
+      # Returns: Hash { id1: extracted_file_name1 },
+      # Example: { "rId1"=>"roo_media_image1.png",
+      #            "rId2"=>"roo_media_image2.png",
+      #            "rId3"=>"roo_media_image3.png" }
+      def list
+        @images ||= extract_images_names
+      end
+
+      private
+
+      def extract_images_names
+        return {} unless doc_exists?
+
+        Hash[doc.xpath('/Relationships/Relationship').map do |rel|
+          [rel['Id'], "roo" + rel['Target'].gsub(/\.\.\/|\//, '_')]
+        end]
+      end
+    end
+  end
+end

lib/roo/excelx/shared.rb

@@ -4,12 +4,15 @@ class Excelx
     #          reduce memory usage and reduce the number of objects being passed
     #          to various inititializers.
     class Shared
-      attr_accessor :comments_files, :sheet_files, :rels_files
+      attr_accessor :comments_files, :sheet_files, :rels_files, :image_rels, :image_files
+
       def initialize(dir)
         @dir = dir
         @comments_files = []
         @sheet_files = []
         @rels_files = []
+        @image_rels = []
+        @image_files = []
       end
 
       def styles

lib/roo/excelx/sheet.rb

@@ -4,11 +4,15 @@ class Excelx
     class Sheet
       extend Forwardable
 
-      delegate [:styles, :workbook, :shared_strings, :rels_files, :sheet_files, :comments_files] => :@shared
+      delegate [:styles, :workbook, :shared_strings, :rels_files, :sheet_files, :comments_files, :image_rels] => :@shared
+
+      attr_reader :images
 
       def initialize(name, shared, sheet_index, options = {})
         @name = name
         @shared = shared
+        @sheet_index = sheet_index
+        @images = Images.new(image_rels[sheet_index]).list
         @rels = Relationships.new(rels_files[sheet_index])
         @comments = Comments.new(comments_files[sheet_index])
         @sheet = SheetDoc.new(sheet_files[sheet_index], @rels, shared, options)

spec/lib/roo/excelx_spec.rb

@@ -534,4 +534,17 @@
       expect(subject.sheet(0).excelx_format(2,1)).to eq 'm/d/yyyy" "h:mm:ss" "AM/PM'
     end
   end
+
+  describe 'images' do
+    let(:path) { 'test/files/images.xlsx' }
+
+    it 'returns array of images from default sheet' do
+      expect(subject.images).to be_kind_of(Array)
+      expect(subject.images.size).to eql(19)
+    end
+
+    it 'returns empty array if there is no images on the sheet' do
+      expect(subject.images("Sheet2")).to eql([])
+    end
+  end
 end