How to convert data into an Excel file

Question

I am using the CSV class to convert data into an Excel file based on http://railscasts.com/episodes/362-exporting-csv-and-excel.

Upon downloading the Excel file it is not updated with the latest data which I see on my webpage using filters. My Excel file contains data which is being shown when the page first loads.

I tried to debug the problem and tried other gems like xlsx_writer, getting the same result:

def commission_report
   today = Date.today
   if params[:from_date].present?
     from_date = params[:from_date]
     to_date = params[:to_date]
   elsif params[:filter] == 'monthly'
     to_date = today
     from_date = today - 30
   else
     to_date = today
     from_date = today - 7
   end
   @commissions_report = UserOrderHistory.select("user_order_histories.*,SUM(user_order_histories.revenue_sharing) as revenue_total, restaurants.restaurant_name, managers.username,revenue_sharings.revenue").joins("LEFT JOIN revenue_sharings ON revenue_sharings.restaurant_id = user_order_histories.restaurant_id").joins("LEFT JOIN restaurants ON restaurants.id = user_order_histories.restaurant_id").joins("LEFT JOIN managers ON managers.id =   restaurants.manager_id").where("user_order_histories.status != ''").where("revenue_sharing > 0").group("user_order_histories.restaurant_id,user_order_histories.deduction_date").where("user_order_histories.deduction_date BETWEEN ? AND ?",from_date,to_date).order(sort_column + " " + sort_direction)
   @commissions_report = @commissions_report.as_json
   @commissions_report = Kaminari.paginate_array(@commissions_report).page(params[:page]).per(10)
  #  raise @commissions.inspect
   respond_to do |format|
     format.html
     format.csv { send_data @commissions_report.to_csv }
     format.xls #{ send_data @commissions_report.to_csv(col_sep:     "\t") }
   end

 end

Answer 1

When you're making the filtered request to download the CSV, the params are not being parsed:

<%= link_to 'Download CSV', your_path(from_date: params[:from_date], to_date: params[:to_date], filter: params[:filter]) %>

This way your params will get sent back again to your controller.

Answer 2

It's because when you click on:

link_to "CSV", products_path(format: "csv")

It goes to the index method in the products controllers and within that method you're again fetching all the records from the DB:

@products = Product.order(:name)

So all you've to do is pass the collection of filtered products to the CSV format respond. Something like this:

format.csv { send_data @filtered_products.to_csv }