1 files changed, 84 insertions, 0 deletions
diff --git a/lib/roo/formatters/csv.rb b/lib/roo/formatters/csv.rb
new file mode 100644
index 0000000..3181f09
--- /dev/null
+++ b/lib/roo/formatters/csv.rb
@@ -0,0 +1,84 @@
+module Roo
+  module Formatters
+    module CSV
+      def to_csv(filename = nil, separator = ",", sheet = default_sheet)
+        if filename
+          File.open(filename, "w") do |file|
+            write_csv_content(file, sheet, separator)
+          end
+          true
+        else
+          sio = ::StringIO.new
+          write_csv_content(sio, sheet, separator)
+          sio.rewind
+          sio.read
+        end
+      end
+
+      private
+
+      # Write all cells to the csv file. File can be a filename or nil. If the
+      # file argument is nil the output goes to STDOUT
+      def write_csv_content(file = nil, sheet = nil, separator = ",")
+        file ||= STDOUT
+        return unless first_row(sheet) # The sheet is empty
+
+        1.upto(last_row(sheet)) do |row|
+          1.upto(last_column(sheet)) do |col|
+            # TODO: use CSV.generate_line
+            file.print(separator) if col > 1
+            file.print cell_to_csv(row, col, sheet)
+          end
+          file.print("\n")
+        end
+      end
+
+      # The content of a cell in the csv output
+      def cell_to_csv(row, col, sheet)
+        return "" if empty?(row, col, sheet)
+
+        onecell = cell(row, col, sheet)
+
+        case celltype(row, col, sheet)
+        when :string
+          %("#{onecell.gsub('"', '""')}") unless onecell.empty?
+        when :boolean
+          # TODO: this only works for excelx
+          onecell = self.sheet_for(sheet).cells[[row, col]].formatted_value
+          %("#{onecell.gsub('"', '""').downcase}")
+        when :float, :percentage
+          if onecell == onecell.to_i
+            onecell.to_i.to_s
+          else
+            onecell.to_s
+          end
+        when :formula
+          case onecell
+          when String
+            %("#{onecell.gsub('"', '""')}") unless onecell.empty?
+          when Integer
+            onecell.to_s
+          when Float
+            if onecell == onecell.to_i
+              onecell.to_i.to_s
+            else
+              onecell.to_s
+            end
+          when Date, DateTime, TrueClass, FalseClass
+            onecell.to_s
+          else
+            fail "unhandled onecell-class #{onecell.class}"
+          end
+        when :date, :datetime
+          onecell.to_s
+        when :time
+          integer_to_timestring(onecell)
+        when :link
+          %("#{onecell.url.gsub('"', '""')}")
+        else
+          fail "unhandled celltype #{celltype(row, col, sheet)}"
+        end || ""
+      end
+    end
+  end
+end