MobileView

Note: Rails 4.1 introduces Action Pack Variants which solves the problem that this gem solves. You man want to use that built-in feature instead of this gem.

Easily specify mobile-specific view template for mobile devices in Rails application.

Warning This gem still has major version of 0 which means it's during early alpha and APIs and usages are subject to change. Strategies and implementations may not be the best practice. Bugs may exist. Feel free to send patches for everyting that you think it's not good or would like to change. I'll add your name to README after approved.

Add this line to your application's Gemfile:

gem "mobile_view", "~> 0.3.0"

And then execute:

$ bundle

Add these lines into your base controller:

class ApplicationController < ActionController::Base
  has_mobile_view
end

• Rails 3.2.x

Development dependency:

• RSpec
• Capybara
• PhantomJS (Capybara's integration test is driven by poltergeist, for easier cookie and header modification.)

If you have problems like this:

1. You have a view template for posts#show, with many DOM elements and JavaScripts, which is good for desktop, but painful for mobile devices. (In such case even Responsive Web Design with CSS media queries doesn't help you much.)

• You're tired of <%= render_something if mobile? %> conditional hell.
• You want to make a mobile-friendly view, which is mostly different from desktop version, build form scratch.

With MobileView, you can add posts/show.mobile.html.erb along with posts/show.html.erb. Then, if the browser is a mobile device, Rails will choose the mobile template first:

• posts/show.html.erb = default view for posts#show
• posts/show.mobile.html.erb = mobile view for posts#show

It also works for partial views and layout views:

• posts/_post.html.erb = default view for partial view posts/post
• posts/_post.mobile.html.erb = mobile view for partial view posts/post

and

• layouts/application.html.erb = default layout
• layouts/application.mobile.html.erb = mobile layout

You can use any template handlers (erb, haml etc.) and formats (json, js, xml etc.) available in your Rails application. All you have to do is add another view template with mobile after the view's main name (before locale, format and handler). It follows the naming rule of Rails's view template files; the only difference is the .mobile interpolation:

• prefix/name.locale.format.handler = default view
• prefix/name.mobile.locale.format.handler = mobile view

When a mobile version of partial view is not available, it will automatically fallback to default (non-mobile) version.

The mobile? helper tells you if currently MobileView switched to mobile version or not. It is available in controller and view.

The situation of "switched to mobile view" could be:

• accessing with a mobile device browser, or
• manually switched to mobile view (see cookie-based switching below).

Returns true if it switched to mobile view, false otherwise.

Example:

# in controller
@text += "Hello! Mobile" if mobile?

<%# in view %>
<%= render_advertisement unless mobile? %>

To use mobile? helper in a mounted engine, for example, Rails Cell, simply include the MobileView::ControllerAdditions module:

class PostCell < Cell::Rails
  include MobileView::ControllerAdditions
  has_mobile_view
end

By setting mobile cookie, you can force it to load mobile views. This is helpful when debugging the app in desktop browsers, or allowing user to switch to mobile version manually.

The cookie injection of manual switching should happen before has_mobile_view is invoked.

Example:

class AppliactionController < ActionController::Base
  before_filter :manual_mobile_switching

  has_mobile_view

  protected
  # Detects `_mobile_view` parameter.
  #
  # If it is 'yes', force turn on mobile view by setting cookie mobile=1;
  # if it is 'no', force turn off mobile view by setting cookie mobile=0;
  # if it is 'auto', remove mobile cookie and fallback to User-Agent mode;
  # otherwise, no effect.
  def mobile_switching
    case params[:_mobile_view]
    when 'yes'
      force_mobile!
    when 'no'
      force_non_mobile!
    when 'auto'
      dismiss_mobile_forcing!
    end
  end
end

According to the algorithm of Rack::MobileDetect, iPad will be seen as a Mobile Device. This may be a fail assumption if you want to show your desktop website to iPad and tablet users. This can (may) be resolved by replacing mobile device detection logic or add more tablet-specific methods.

Workaround: Force switch to non-mobile version when client is iPad:

class AppliactionController < ActionController::Base
  before_filter :force_non_mobile!, :if => :ipad?

  # still have to invoke has_mobile_view after force_mobile!
  has_mobile_view
end

• #269 Template Inheritance - RailsCasts
• #397 Action View Walkthrough (pro) - RailsCasts
• Implementing a Rails 3 View Resolver - jkfill blog

• [breaking] Fron now on you have to invoke has_mobile_view in controller explicitly.
• Wrap cookie-based switching into a bunch of helper methods for code readability.

• Support cookie-based switching
• [breaking] Rename helper mobile_device? to mobile? since it now not only detects mobile device, but also accepts cookie-based switching.
• Ability to have other mounted engines use mobile? helper. (Inspired from Devise)

🎂 First Release

• *.mobile view template auto-overriding
• Automatic mobile device detection
• mobile_device? helper for controller and view

The MIT License

Copyright (c) 2012 Yu-Cheng Chuang

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.