rails2

Speaking of the iPhone, we’ve made it easier to declare “fake” types that are only used for internal routing. Like when you want a special HTML interface just for an iPhone. All it takes is something like this:

  # should go in config/initializers/mime_types.rb
  Mime.register_alias "text/html", :iphone

  class ApplicationController < ActionController::Base
    before_filter :adjust_format_for_iphone

    private
      def adjust_format_for_iphone
        if request.env["HTTP_USER_AGENT"] && request.env["HTTP_USER_AGENT"][/(iPhone|iPod)/]
          request.format = :iphone
        end
      end
  end

  class PostsController < ApplicationController
    def index
      respond_to do |format|
        format.html   # renders index.html.erb
        format.iphone # renders index.iphone.erb
      end
    end
  end

Action Pack: Exception handling

Lots of common exceptions would do better to be rescued at a shared level rather than per action. This has always been possible by overwriting rescue_action_in_public, but then you had to roll out your own case statement and call super. Bah. So now we have a class level macro called rescue_from, which you can use to declaratively point certain exceptions to a given action. Example:

  class PostsController < ApplicationController
    rescue_from User::NotAuthorized, :with => :deny_access

    protected
      def deny_access
        ...
      end
  end