Where should I place code which generates Excel spreadsheet?

Question

I am using spreadsheet gem to generate native Excel file. This is not CSV, XML file. Ordinary Ruby code is used to create the file. The generated Excel file (kept in StringIO) is forwarded to a client using send_data method. I need send_data method because of its parameters like disposition.

The data for the Excel is retrieved in controller method just like for ordinary HTML, JS requests. However I placed the code to generate the spreadsheet in controller protected method. Not in a view as I should.

Is there an elegant solution to above problem compliant with MVC design pattern?

Update: There is no popular and accepted by all solution to above problem but at least I know all possible ideas.

Answer 1

The lib directory is meant as a place for code that isn't strictly part of the MVC structure, but will be needed by multiple models, views, or controllers. It can be brought in with a require when needed.

However, if you only need the code in a single controller, you'd be just as well off putting it into that controller's helper. That way it's auto-loaded and at your fingertips. Plus, it makes sense: it's code to help a specific controller.

Either way, don't leave it in your controller or try to wedge it into your view.

Answer 2

i just did this today for my app hope this helps for an excel o/p ; never used any plugin

controller: def export pr = Program.find(session[:pr_id]) headers['Content-Type']="application/vnd.ms-excel" headers['Content-Dispositon']='attachment;filename="report.xls"' @voucherdatas = Voucherdata.find_all_by_pr_name(pr.pr_name) end

view: export.html.erb

manager "reports/voucherdatas", :object =>@voucherdatas %>

routes.rb map.resources :reports ,:collection =>{:export =>:get}

whereever u want the link give

link_to "Export As Excel", export_reports_url, :popup=>true

Answer 3

1. Create an excel library in your lib folder in which you include your xls generation routine as well as a method that overrides ActionController's render method.
2. In a model that should be rendered as xls implement a method called to_excel method which generates a hash that you can provide to your xls routine.

3. Doing it this way, you'll get something really "Railsy". In your controller you'll just call

   render :xls => @model