old-code.rb

def build_page_data
  current_id = nil
  categories = {}
  features = []
  
  @page_data.each do |row|
    if row[:group_id] != current_id
      categories[current_id][:features] = features unless features.empty?
      features = []
      current_id = category[:group_id]
      
      categories[category[:group_id]] = format_data(row)
      end
    
    features << features_hash(row)
  end
  
  categories[current_id][:features] = features unless features.empty?
  
  categories
end