Passes user-given options to Spreadsheet::Format

lib/daru/io/exporters/excel.rb

@@ -8,10 +8,21 @@ class Excel < Base
 
         # Exports +Daru::DataFrame+ to an Excel Spreadsheet.
         #
+        # @note To know more about the +Spreadsheet+ parameter hashes that can be given as
+        #   +data_options+ and +header_options+ parameters, please have a look at the methods
+        #   described in
+        #   {http://www.rubydoc.info/gems/ruby-spreadsheet/Spreadsheet/Font Spreadsheet::Font}
+        #   and
+        #   {http://www.rubydoc.info/gems/ruby-spreadsheet/Spreadsheet/Format Spreadsheet::Format}
+        #   pages.
+        #
         # @param dataframe [Daru::DataFrame] A dataframe to export
         # @param path [String] Path of the file where the +Daru::DataFrame+
         #   should be written.
-        # @param options [Hash] A set of options containing user-preferences
+        # @param data_options [Hash] A set of +Spreadsheet+ options containing user-preferences
+        #   about the +Daru::DataFrame+ data being written.
+        # @param header_options [Hash] A set of +Spreadseet+ options containing user-preferences
+        #   about the +Daru::DataFrame+ headers being written.
         #
         # @example Writing to an Excel file without options
         #   df = Daru::DataFrame.new([[1,2],[3,4]], order: [:a, :b])
@@ -23,32 +34,42 @@ class Excel < Base
         #
         #   Daru::IO::Exporters::Excel.new(df, "dataframe_df.xls").call
         #
-        # @todo The +opts+ parameter isn't used while creating the Excel Spreadsheet
-        #   yet. Implementing this feature will greatly allow the user to generate a
-        #   Spreadsheet of their choice.
-        def initialize(dataframe, path, **options)
+        # @example Writing to an Excel file with options
+        #   df = Daru::DataFrame.new([[1,2],[3,4]], order: [:a, :b])
+        #
+        #   #=> #<Daru::DataFrame(2x2)>
+        #   #      a   b
+        #   #  0   1   3
+        #   #  1   2   4
+        #
+        #   normal  = { color: :blue }
+        #   heading = { color: :red, weight: :bold }
+        #
+        #   Daru::IO::Exporters::Excel.new(df,
+        #     "dataframe_df.xls",
+        #     data_options: normal,
+        #     header_options: heading
+        #   ).call
+        def initialize(dataframe, path, header_options: {}, data_options: {})
           optional_gem 'spreadsheet', '~> 1.1.1'
 
           super(dataframe)
-          @path      = path
-          @options   = options
+          @path           = path
+          @data_options   = data_options
+          @header_options = header_options
         end
 
-        # @note
-        #
-        #   The +format+ variable used in this method, has to be given
-        #   as options by the user via the +options+ hash input.
-        #
-        #   Signed off by @athityakumar on 03/06/2017 at 7:00PM
         def call
           book  = Spreadsheet::Workbook.new
           sheet = book.create_worksheet
 
-          format = Spreadsheet::Format.new color: :blue, weight: :bold
+          sheet.row(0).concat(@dataframe.vectors.to_a.map(&:to_s))
+          sheet.row(0).default_format = Spreadsheet::Format.new(@header_options)
 
-          sheet.row(0).concat(@dataframe.vectors.to_a.map(&:to_s)) # Unfreeze strings
-          sheet.row(0).default_format = format
-          @dataframe.each_row_with_index { |row, i| sheet.row(i+1).concat(row.to_a) }
+          @dataframe.each_row_with_index do |row, i|
+            sheet.row(i+1).concat(row.to_a)
+            sheet.row(i+1).default_format = Spreadsheet::Format.new(@data_options)
+          end
 
           book.write(@path)
         end