productions_controller.rb

class ProductionsController < ApplicationController
  #...

  # GET /productions/1
  # GET /productions/1.xml
  # Alternately, old URLs:
  # GET /productions/2009/11/23/Hyphenated-Title
  def show
    # Identify production if we got here by /month/day/year/slug URL,
    # e.g. links generated for the old RPI TV website.
    # We will not support production.php?prodid=123 due to server configs.
    if params[:year] && params[:month] && params[:day]
      possibilities = Production.find_all_by_release_date(
        params[:year].to_s + '-' +
        params[:month].to_s + '-' +
        params[:day].to_s
      )
      if possibilities.size == 1
        # Only one. Got it!
        @production = possibilities.first
      elsif possibilities.size > 1
        # Not conclusive. We'll apply the transformation that was used
        # for the old php-based rpitv website to see if we can make an ID.
        possibilities.each do |prod|
          old_slug = prod.title.gsub(/[^A-Za-z0-9]+/,'-')
          if params[:slug]==old_slug
            #This matches.
            @production = prod
            break
          end
        end
      end
    end # 0 results means we just try id lookup below.

    # Go ahead with the normal identification if we haven't identified
    # the production some other way.
    if @production.nil?
      @production = Production.find(params[:id], :include => :category)
    end

    # Redirect to the proper URI, if we're not there already.
    # Stop rendering if the redirect is requested.
    ensure_uri production_path(@production) or return

    # ... Continue on to rendering, etc.
  end

  #...
end