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, iPad, Nokia, etc. and it will automatically adjust the format of the request from :html to :mobile or :tablet.

Simply add gem 'mobile-fu' to your Gemfile and run bundle install.

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 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.

If you do not want to set the format to :mobile or :tablet and only use the helper functions, pass false as an argument.

class ApplicationController < ActionController::Base
  has_mobile_fu false
end

If you dont want to have all the methods respond to :mobile and :tablet, you can opt-in this actions using the following class method: has_mobile_fu_for :action Example:

class YourAwesomeClass < ActionController::Base
  has_mobile_fu
  has_mobile_fu_for :index

  def index
    # Mobile format will be set as normal here if user is on a mobile device
  end

  def another_method
    # Mobile format will not be set, even if user is on a mobile device
  end

Mobile Fu automatically adds a new :mobile and :tablet to text/html mime type alias for Rails apps. If you already have a custom :mobile alias registered in config/initializers/mime_types.rb, you can remove that.

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 or

is_tablet_device? # => Returns true if the device is a tablet

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

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

in_tablet_view? # => Returns true if the current req. format is for tablet view

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

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

If you want to use the default response templates, like index.html.erb, instead of the index.tablet.erb you can exclude the tablet rendering from beeing used: you can create a before_filter and put it before the has_mobile_fu call

before_filter :force_tablet_html
has_mobile_fu

def force_tablet_html
	session[:tablet_view] = false
end

Same will work for mobile, just change the tablet values to mobile

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)
• ipad
• android
• mobileexplorer
• nokia
• palm

The stylesheet awesomeness was derived from Michael Bleigh's browserized styles

Inspiration for Mobile Fu came from Noel Rappin's rails_iui

Hopefully this should help you create some awesome mobile applications.

If you want to force the mobile interface for testing, you can either use a mobile device emulator, or you can call force_mobile_format in a before filter.

class ApplicationController < ActionController::Base
  has_mobile_fu
  before_filter :force_mobile_format
end

You can also force the tablet view by calling force_tablet_format instead

class ApplicationController < ActionController::Base
  has_mobile_fu
  before_filter :force_tablet_format
end

Copyright (c) 2008 Brendan G. Lim, Intridea, Inc., released under the MIT license