Merge pull request #27 from kamilhism/fix-dates-convert-issues

Get date attribute from workbookPr and use it during dates conversion

Author: pythonicrubyist

lib/creek/book.rb

@@ -1,5 +1,6 @@
 require 'zip/filesystem'
 require 'nokogiri'
+require 'date'
 
 module Creek
 
@@ -9,6 +10,9 @@ class Creek::Book
                 :sheets,
                 :shared_strings
 
+    DATE_1900 = Date.new(1899, 12, 30).freeze
+    DATE_1904 = Date.new(1904, 1, 1).freeze
+
     def initialize path, options = {}
       check_file_extension = options.fetch(:check_file_extension, true)
       if check_file_extension
@@ -37,5 +41,26 @@ def style_types
     def close
       @files.close
     end
+
+    def base_date
+      @base_date ||=
+      begin
+        # Default to 1900 (minus one day due to excel quirk) but use 1904 if
+        # it's set in the Workbook's workbookPr
+        # http://msdn.microsoft.com/en-us/library/ff530155(v=office.12).aspx
+        result = DATE_1900 # default
+
+        doc = @files.file.open "xl/workbook.xml"
+        xml = Nokogiri::XML::Document.parse doc
+        xml.css('workbookPr[date1904]').each do |workbookPr|
+          if workbookPr['date1904'] =~ /true|1/i
+            result = DATE_1904
+            break
+          end
+        end
+
+        result
+      end
+    end
   end
 end

lib/creek/sheet.rb

@@ -85,7 +85,10 @@ def convert(value, type, style_idx)
     end
 
     def converter_options
-      @converter_options ||= {shared_strings: @book.shared_strings.dictionary}
+      @converter_options ||= {
+        shared_strings: @book.shared_strings.dictionary,
+        base_date: @book.base_date
+      }
     end
 
     ##

lib/creek/styles/constants.rb

@@ -1,5 +1,3 @@
-require 'date'
-
 module Creek
   class Styles
     module Constants
@@ -38,9 +36,6 @@ module Constants
         48 => :bignum,         # ##0.0E+0
         49 => :unsupported     # @
       }
-
-      DATE_SYSTEM_1900 = Date.new(1899, 12, 30)
-      DATE_SYSTEM_1904 = Date.new(1904, 1, 1)
     end
   end
 end

lib/creek/styles/converter.rb

@@ -81,7 +81,7 @@ def self.convert_date(value, options)
         fraction_of_24               = value - days_since_date_system_start
 
         # http://stackoverflow.com/questions/10559767/how-to-convert-ms-excel-date-from-float-to-date-format-in-ruby
-        date = options.fetch(:base_date, DATE_SYSTEM_1900) + days_since_date_system_start
+        date = options.fetch(:base_date, Date.new(1899, 12, 30)) + days_since_date_system_start
 
         if fraction_of_24 > 0 # there is a time associated
           seconds = (fraction_of_24 * 86400).round
@@ -98,21 +98,6 @@ def self.convert_bignum(value)
           value.to_f
         end
       end
-
-      ## Returns the base_date from which to calculate dates.
-      # Defaults to 1900 (minus two days due to excel quirk), but use 1904 if
-      # it's set in the Workbook's workbookPr.
-      # http://msdn.microsoft.com/en-us/library/ff530155(v=office.12).aspx
-      def base_date
-        @base_date ||= begin
-          # return DATE_SYSTEM_1900 if xml.workbook == nil
-          # xml.workbook.xpath("//workbook/workbookPr[@date1904]").each do |workbookPr|
-          #   return DATE_SYSTEM_1904 if workbookPr["date1904"] =~ /true|1/i
-          # end
-          DATE_SYSTEM_1900
-        end
-      end
-
     end
   end
 end