Collapsed outline level

outline_level.rb

  
  #```ruby
  wb.add_worksheet(name: 'outline_level') do |sheet|
    sheet.add_row [1, 2, 3, 4, Time.now, 149455.15]
    sheet.add_row [1, 2, 5, 6, Time.now,14100.19]
    sheet.add_row [9500002267, 1212, 1212, Time.now,14100.19]
    sheet.add_row [], :collapsed => 1
    sheet.rows[0..2].each do |row|
      row.outline_level = 1
      # This will collapse the outline level rows
      row.hidden = true
    end
    sheet.column_info[0..2].each do |col|
      col.outline_level = 1
      #This will collapse the outline level cols
      col.hidden = true
    end
    # This will show the show the [+] symbols
    sheet.sheet_view do |view|
      view.show_outline_symbols=true
    end
  end
#```

I'm thinking this could be made a bit easier by adding something to worksheet like:

def outline_rows(start_index, end_index, level = 1, collapsed = true

So Ive added two helper methods to worksheet.

You can do the same thing as you have above by calling

sheet.outline_rows (sheet.rows.size - rows_data_array.size), sheet.rows.size

It will enable the outline symbols and collapse the rows by default.
Ive added a similar method for outline_columns as well.