Mobile Fu

Want to automatically detect mobile devices that access your Rails application? Mobile Fu allows you to do just that. People can access your site from a Palm, Blackberry, iPhone, Nokia, etc. and it will automatically adjust the format of the request from :html to :mobile.

Usage

Add this this one line to the controller.

    class ApplicationController < ActionController::Base
      has_mobile_fu
    end

Once this is in place, any request that comes from a mobile device will be be set as :mobile format. It is up to you to determine how you want to handle these requests. It is also up to you to create the .mobile.erb versions of your views that are to be requested.

Then add the line below to config/initializers/mime_types.rb

  Mime::Type.register_alias "text/html", :mobile

I recommend that you setup a before_filter that will redirect to a specific page depending on whether or not it is a mobile request. How can you check this?

  is_mobile_device? # => Returns true or false depending on the device

You can also determine which format is currently set in by calling the following:

  is_mobile_view? # => Returns true or false depending on current req. format

Also, if you want the ability to allow a user to switch between ‘mobile’ and ‘standard’ format (:html), you can just adjust the mobile_view session variable in a custom controller action.

  session[:mobile_view] # => Set to true if request format is :mobile and false
                             if set to :html

So, different devices need different styling. Don’t worry, we’ve got this baked in to Mobile Fu.

If you are including a css or sass file via stylesheet_link_tag, all you have to do is add _device to the name of one of your files to override your styling for a certain device. The stylesheet that is loaded is dependant on which device is making the request.

  e.g., Accessing a page from a Blackberry.

  ...  stylesheet_link_tag 'mobile.css' ...

  This loads mobile.css, and mobile_blackberry.css if the file exists.

Supported stylesheet override device extensions at the moment are:

  blackberry
  iphone (iphone,ipod)
  android
  mobileexplorer
  nokia
  palm

The stylesheet awesomeness was derived from Michael Bleigh’s browserized styles: www.intridea.com/2007/12/9/announcing-browserized-styles

Inspiration for Mobile Fu came from Noel Rappin’s rails_iui: blogs.pathf.com/agileajax/2008/05/rails-developme.html

Hopefully this should help you create some awesome mobile applications.

Testing Mobile Interface

If you want to force the mobile interface for testing, you can either use a mobile device emulator, or you can pass ‘true’ to has_mobile_fu.

  class ApplicationController < ActionController::Base
    has_mobile_fu(true)
  end

Copyright © 2008 Brendan G. Lim, Intridea, Inc., released under the MIT license