Rails axlsx gem-公式无法转义

Question

Is there a way to ignore executing a formula while rendering spreadsheet?

Currently, sheet.add_row("=10+10") will evaluate 20, even if I give :formula => :false or :type=> :string

The only hacky way is to provide a single quote, but it's not a pretty approach.

Answer 1

I found an answer for this in Stop Excel from automatically converting certain text values to dates

require 'axlsx'
Axlsx::Package.new do |p|
  p.workbook.add_worksheet(:name => 'DATA') do |sheet|
    sheet.add_row(['="10+10"', 'Maybe this is the best solution'])
    sheet.add_row(["'10+10", 'Hack with single quote'])
  end    
  p.serialize('test.xlsx')
end

This results in:

Answer 2

I looked at the source code of the gem in question, the following code is there:

def is_formula?
   @type == :string && @value.to_s.start_with?('=')
end

It means that anything of type string with '=' will be treated like a formula. And the only accepted types are date, string, integer, float etc. Anything else in place of :type => :string and it does not accept it.

As an alternative, I had to open the class cell_serializer.rb in the gem and reimplement the method in a custom way to get rid of cell.is_formula? check.

def string_type_serialization(cell, str='')
      if cell.is_formula?
        formula_serialization cell, str
      elsif !cell.ssti.nil?
        value_serialization 's', cell.ssti.to_s, str
      else
        inline_string_serialization cell, str
      end
 end

Reimplemented method:

def string_type_serialization(cell, str='')
        if !cell.ssti.nil?
          value_serialization 's', cell.ssti.to_s, str
        else
          inline_string_serialization cell, str
        end
end

I realize it's a hacky way, but it affects system wide code. If I need anything complex in future, I can always make changes to one central place.

Answer 3

I found another approach. In the approach mentioned in this answer, although the formula is not executed when the spreadsheet opens, it is evaluated if the user clicks on it and then blurs away. This might not be the best solution.

Better solution is to wrap any excel functions in TEXT function. This ensures the formulae is not executed.

eg

= 9 + 9 can be substituted with =TEXT("9+9","#"), and it will be printed as it is, without evaluation.