Question

I have a method called “revisions”, and I want to be able use the same logic but output to csv. I think I’d like to use the FasterCSV gem. What I need is to what to add to my routes in order to get a route for both the html and the csv outputs. I’d like my urls to be something like this:

invoices/51/revisions
invoices/51/revisions.csv

Thoughts?

Thanks much!

Answer 1

Rails makes this very easy. You don’t need to change your routes at all to accommodate CSV format, since rails recognizes the csv MIME-type.

First, set up a route in routes.rb:

map.invoice_revisions 'invoices/:id/revisions.:format', 
                      :controller=>:invoices, 
                      :action=>:revisions 

In your controller, do something like this:

def revisions
  # ... set @revisions with something like
  @revisions = Invoice.find(params[:id]).revisions

  respond_to do |format|
    format.html # will render the revisions html template
    format.csv { render :csv => revisions_csv } # see sample method below
    end
  end
end

private
  def revisions_csv # convert @revisions to csv: customize to your needs
    FasterCSV.generate do |csv|
      csv << @revisions.first.attributes.keys  # set the headers
      @revisions.each do |revision|            # set the data
        csv << revision.attributes.values
      end
    end
  end

Here’s a tutorial with more detailed info on formatting the csv files using csvbuilder:

http://rubyglasses.blogspot.com/2009/07/csv-views-with-fastercsv-and-csvbuilder.html