Monday, November 07, 2011

Adding Mobile Support with Web 2.0 Touch to the NoAgenda Attack Vector Dashboard

The quest for an ideal javascript framework for mobile web applications has been a bit of a work-in-progress for some time (at least if you cared about cross-platform).

You might have got started (like me) with Jonathan Stark's excellent books Building iPhone Apps with HTML, CSS, and JavaScript and Building Android Apps with HTML, CSS, and JavaScript, and maybe tried the jQTouch framework that these spawned. Meanwhile, the official jQuery mobile framework has slowly been moving to fruition.

I recently discovered another project - Web 2.0 Touch - that is pitched as a mini framework with better features and more ease of use than jQTouch. Since I had a little side-project underway that could benefit from mobile support, I thought I'd give it a test drive.

And I was duly impressed. In just a few hours, I had a full and distinct mobile version of the site. Better yet, I didn't run into any weird behaviours that can plague mobile development. It just worked.

Now I'm not going to stop tracking the jQuery Mobile project or other solutions like Rhomobile, but if all you need is a quick, functional and good looking mobile view, then Web 2.0 Touch is well worth a look.

The NoAgenda Attack Vector Dashboard is the project I used Web 2.0 Touch for, and if you want to see all the intricate details of how I made the site mobile-friendly - you can! The entire site is open sourced and available on
GitHub. I'll just describe a couple of the features here...

Differentiated Views

The first has not much to do with Web 2.0 Touch per se, and is more just a demonstration of how easy it is to work with a range of view technologies in Rails.

Since the application has a very specific and rich desktop presentation, I knew the mobile version was going to be very different. Here are the desktop and mobile "home pages" side-by-side:


Rather than weigh down view code with lots of conditionals, I decided to use the MIME-type method of differentiation.

If you haven't used this before, it essentially means registering a suitable MIME-type (I called it mobile), and in the main ApplicationController, the request.format is set to this type if the client is detected to require the special mobile view. Now a request to an :index page will render with index.mobile.erb (or index.mobile.haml as is my preference), while the non-mobile view will render with index.html.erb / index.html.haml.

I've added the browser gem to the project for device identification, and for this app I've decided to only specifically handle iPhone and Android. I also don't give these phones a desktop view alternative, since I know it is not going to be nice.
# config/initializers/mime_types.rb:
Mime::Type.register_alias "text/html", :mobile

# application_controller.rb:
class ApplicationController < ActionController::Base
  before_filter { request.format = :mobile if (browser.iphone? || browser.android?) }
end
With that in place, my *.mobile.haml view and layout files just need to focus on rendering the mobile site.

Page Transitions

The jsTouch.loadPage method is used to load and navigate pages in the Web 2.0 Touch framework.

In the application, I've made this 'unobtrusive' so it might be worth pointing out what is going on. The .touch_load class is used to tag items that should initiate a page transition. The data-url and data-transition attributes tell it where to go and what transition animation to use.
.toolbar
  %h1= t('.title')
  %a.button.back.touch_load{'data-url' => menu_dashboard_path, 'data-transition' => 'pop-out' }= t(:done)
.content
  = render :partial => 'notes/table'
The enableSmartphonePageLoad function runs during page load to setup the behaviour:
  enableSmartphonePageLoad: function() {
    $('.touch_load').live('click', function() {
      var url = $(this).data('url') || $(this).attr('href');
      var transition = $(this).data('transition') || 'slide-left';
      if (url != "") {
        jsTouch.loadPage(url, { transition: transition });
      }
      return false;
    });
  },

Blogarhythm: Touch - Noiseworks