gistfile1.rb

# app/controller/tasks_controller.rb
class TasksController < ApplicationController
  def index
    @tasks = Task.all
    respond_to do |format|
      format.html
      format.pdf {
        report = ThinReports::Report.new :layout => '/path/to/tasks.tlf'
        
        @tasks.each do |task|
          report.list.add_row :name => task.name
        end

        send_data report.generate, :filename => 'tasks.pdf', 
                                   :type     => 'application/pdf'
      }
    end
  end
end