Click here to close now.


Java IoT Authors: Tim Hinds, Pat Romanski, Brian Daleiden, Derek Weeks, Automic Blog

Related Topics: Java IoT, Mobile IoT, Wearables

Java IoT: Article

Living on the Edge of Mobile Development

Overview and experience with Sencha Touch, YUI Test and PhoneGap

Which mobile device should I target for my application? That's one of the first questions you need to answer as a mobile developer. You might select the device based on personal preference or what looks cool today. The problem is that mobile technology choices are diverse and evolving quickly. The tools and languages used to develop native applications vary wildly and you probably cannot afford to learn them all. Chances are you want to find a way to replicate your application across multiple devices while minimizing your investment.  How can that be done?

Hybrid Is More than a Green Decision
We are all familiar with the idea of hybrid cars and trucks. These vehicles typically combine petroleum and electric technologies to improve efficiency, reducing your carbon footprint.  You can take a hybrid approach for your mobile application by combining multiple technologies to improve your development efficiency, reducing your expenses.  The hybrid approach combines minimal device-specific native code with your application developed with HTML5, CSS3 and JavaScript.  Development of native code is painless through the use of several libraries and tools.  HTML5 provides the underlying capability for storage, drag and drop, timed media playback, and others.  CSS3 dramatically improves the presentation of web technologies enabling a native look-and-feel for mobile applications. JavaScript allows you to use your existing web skills to implement the application.  All of these technologies run within a compatible desktop browser allowing you to develop and test your application without deploying to a device.

The combination of familiar web technologies with minimal native code enables you to develop your application once and deploy to a variety of mobile devices.  Now you might be thinking 'Are these web standards finalized?' and the answer would be no.  However, the HTML rendering engines used in most mobile devices have been implementing the features as the standards are published.  Javascript libraries are wrapping these features and compensating for device differences and standards evolution so your application does not need to.  There are several libraries under development but I elected to use Sencha Touch.

Figure 1 - This diagram depicts the major differences between mulitple native and hybrid application development

Sencha Touch Is My Cup of Tea
The Sencha company logo is a green leaf, presumably because sencha is a Japanese whole leaf green tea.  I am an ardent coffee drinker but I really like this tea.  Sencha is perhaps best known for their Ext JS and Ext GWT libraries.  Sencha Touch is their latest library released late in 2010.  There are several similar libraries in various stages of development, but Sencha was one of the first to market and I am working on commercial products that depend on released libraries.  The first release includes support for Android and Apple iOS devices.  Reading the tea leaves promises future support for Blackberry 6 and Blackberry Torch.  The library is open source and supports a dual license approach making it appropriate for commercial use.  The library includes:

  • Robust data integration including access to AJAX, JSONP, or YQL and local storage
  • Large library of user interface elements many of which automatically bind to the data objects
  • Advanced native look-and-feel styling, animation and branding capabilities
  • Model, View, Controller (MVC) support to put it all together

Figure 2 - Example Sencha Touch application running on Apple iPhones

My First Sips of Sencha
I started using Sench Touch in the Summer of 2010 while it was in beta.  I had the typical beta experience of incomplete documentation, a few bugs and changing API.  Over the frequent updates, the documentation improved and examples were updated to align with the latest API.  Throughout the beta and after the production release, I worked on my application.  My application successfully used local storage, tree and carousal navigation, animated transitions, custom search features and selective user updates to content.  The plan is to deploy on Apple iOS devices first with the need for possibly many different branding themes.

I found it quite easy to define enities and storage objects with the data integration features.  The storage objects were extensible enough to add custom search features.  The user interface elements often took some experimentation and reverse engineering to fill in the gaps of light documentation.  I had to become familiar with the inspection and debugging features of Chrome and Safari to ultimately answer many questions.  There are still a few inconsistencies in how user interface element templates are used but overall, the library is quite complete.  One of the most powerful user interface features is the branding support.

The branding support in Sencha uses Syntactically Awesome Stylesheets (SASS). SASS is a scripting language that describes how to generate cascading stylesheets.  Need to change your corporate color across all user interface elements?  Change it in one place and regenerate your native look-and-feel stylesheet.  Sencha Touch ships with a full library of SASS scripts that you can easily extend to meet your branding needs.  This approach also encodes images into the stylesheet to reduce the number of files to deploy.  I was able to extend the SASS to specify branding color selections, omit unused user interface elements and specify the needed icons.

Sencha provides best practice advice for project organization and the use of the MVC support.  Part of the project organization is for unit testing. It is your choice how to test your JavaScript, but the best practice within our organization for other technologies is to use one of the xUnit libraries and include regression testing as part of continuous integration.  I did an informal survey within our development group and found that Javascript is an exception.  Since the bulk of a hybrid application is JavaScript, I found it necessary to evaluate and select a suitable unit testing approach.

Figure 3 - You can also write applications for the Apple iPad

This is Only a Test
A robust JavaScript unit testing library should include support for:

  • Continuous integration
  • Multiple browser testing
  • Event testing
  • Mock objects
  • Organization of tests (e.g. suites)
  • Code coverage reports

I looked at two dozen different options and selected the YUI Test Standalone Library.  This is a project to separate the Test module from the popular Yahoo! UI framework.  It is currently released as a beta and appears to be slated for a first quarter 2011 release.  Running unit tests requires the use of a desktop browser.  Javascript is used to set up the test environment including the suites and tests.  I found the suites and tests to be very similar to JUnit tests.  Several examples are included and enabled me to create a regression suite with a nice summary report like this:

Figure 4 - A unit testing console for displaying progress and results

Manually reviewing unit test results should not be included in a continuous integration development environment. The YUI Test Standalone library includes integration with Selenium Remote Control (RC) to automate the regression test.  Selenium RC is a test server that controls browser sessions for testing your JavaScript. The YUI Test Selenium driver enables a build script to:

  1. Start the Selenium RC server
  2. Specify the regression test HTML files
  3. Specify the browsers to run the regression
  4. Run the tests
  5. Collect and report the success or failure of the tests
  6. Optionally create coverage reports
  7. Shutdown the Selenium RC server

All of these tasks are done via the Java-based driver included in YUI Test Standalone and can be included as part of a build such as Ant. The coverage report is conditional on a earlier instrumentation step (not shown).  The YUI Test Standalone library includes a Java-based instrumentation utility that creates instrumented Javascript proxies of the files targeted for coverage measurement.  The coverage report step above depends on the instrumented proxies to creat LCOV-based coverage reports. These coverage reports include a very nice report of line and function coverage including a line by line color coding of the coverage of the source.

Going Native
Up to this point, all development and testing has been done on a desktop running Chrome or Safari.  This has enabled a fast turn around in development and the possible use of browser-based web interface testing automation by a quality assurance group.  This is not to say that all testing can be done on the desktop.  Ultimately, device testing is needed and should be done early and often.  How can we get our HTML, CSS and Javascript to run natively on a mobile device?  The hybrid approach we introduced above would have us write a small program in the target technology that wraps and invokes the application.  Luckily, there are libraries and tools that make this painless.  PhoneGap is the option selected for this project.

PhoneGap fills the technology gap between JavaScript and the native mobile device. It provides JavaScript APIs to underlying native function such as:

  • Accelerometer
  • Camera
  • Compass
  • Contacts
  • Geolocation
  • Media
  • Storage
  • Others

PhoneGap also provides console integration with desktop debuggers, support for six platforms and integrated development environment (IDE) project templates. You must have your target platform SDK installed to use PhoneGap. Since my project is targeting Apple iOS, that means a Mac running the Xcode IDE and the iOS SDK. After downloading and installing the IDE, SDK and PhoneGap, a new project template was available. I created a new PhoneGap project and the template created all the native programs, build targets and default properties and images for me. I copied the application build results into the Xcode project, pressed Build and Run and the application was running in the phone simulator.  It was that simple. No Objective-C to learn or write with less than a day from install to running.

Gaps with PhoneGap
Despite the trivial effort to get the application running on the simulator, there were three minor gaps to address:

  • The default target is iPhones.  This means the application would start up and run on an iPad with the dimensions of a phone (with the 2x option).  Sencha Touch reported the platform as a phone even when running on the actual iPad device.  Ideally, the default would be what Apple calls a Universal App that runs on all devices and adjusts itself when running.  After some research, I found that the solution was few mouse clicks away within Xcode.
  • Orientation changes did not work.  A Sencha Touch application can change the way it looks based on the orientation of the device.  PhoneGap always reported the device orientation as portrait (0 degrees) even though Sencha Touch correctly reported the current orientation.  The solution was a minor hack to monitor for the window resize event and inform Sencha Touch to do the right thing.
  • Certain text was rendered as a link.  Clicking on the link offered to add or update a contact.  What was that all about?  It turns out the default web view component in the iOS SDK attempts to find phone number and e-mail addresses and automatically makes them links to the appropriate app like contacts.  Pretty cool if you want that behavior but does 001-999.9 look like a phone number?  The solution was to add one line of Objective-C code in the PhoneGap generated code to turn this behavior off.

Live Long and Provision
In order to get your application running on an actual device you must go through a complex process Apple calls provisioning.  There is a nice step by step procedure to get you through it all available on the Apple developer site.  Now that I have my Sencha Touch application running on an iPad I see that performance work is needed.  Now that automated build and test process is going to pay off.  It is clear to me that a robust development cycle with this technology is possible and practical.

There are bound to be changes in the available libraries and supported devices in the coming months.  Sencha Touch and PhoneGap is a powerful and easy to use combination that is ready now.


  • Opinions expressed in this article are those solely of the author and do not reflect those of my employer.
  • iPhone image Courtesy of Apple
  • Sencha Touch application images used with permission
  • The Android logo is reproduced from work created and shared by Google and used according to terms described in the Creative Commons 3.0 Attribution License.


More Stories By Mike Jacobs

Mike Jacobs is technology architect and Technology Fellow focused on using technology to improve health care.

@ThingsExpo Stories
Today air travel is a minefield of delays, hassles and customer disappointment. Airlines struggle to revitalize the experience. GE and M2Mi will demonstrate practical examples of how IoT solutions are helping airlines bring back personalization, reduce trip time and improve reliability. In their session at @ThingsExpo, Shyam Varan Nath, Principal Architect with GE, and Dr. Sarah Cooper, M2Mi’s VP Business Development and Engineering, explored the IoT cloud-based platform technologies driving this change including privacy controls, data transparency and integration of real time context with p...
The Internet of Things (IoT) is growing rapidly by extending current technologies, products and networks. By 2020, Cisco estimates there will be 50 billion connected devices. Gartner has forecast revenues of over $300 billion, just to IoT suppliers. Now is the time to figure out how you’ll make money – not just create innovative products. With hundreds of new products and companies jumping into the IoT fray every month, there’s no shortage of innovation. Despite this, McKinsey/VisionMobile data shows "less than 10 percent of IoT developers are making enough to support a reasonably sized team....
Just over a week ago I received a long and loud sustained applause for a presentation I delivered at this year’s Cloud Expo in Santa Clara. I was extremely pleased with the turnout and had some very good conversations with many of the attendees. Over the next few days I had many more meaningful conversations and was not only happy with the results but also learned a few new things. Here is everything I learned in those three days distilled into three short points.
DevOps is about increasing efficiency, but nothing is more inefficient than building the same application twice. However, this is a routine occurrence with enterprise applications that need both a rich desktop web interface and strong mobile support. With recent technological advances from Isomorphic Software and others, rich desktop and tuned mobile experiences can now be created with a single codebase – without compromising functionality, performance or usability. In his session at DevOps Summit, Charles Kendrick, CTO and Chief Architect at Isomorphic Software, demonstrated examples of com...
As organizations realize the scope of the Internet of Things, gaining key insights from Big Data, through the use of advanced analytics, becomes crucial. However, IoT also creates the need for petabyte scale storage of data from millions of devices. A new type of Storage is required which seamlessly integrates robust data analytics with massive scale. These storage systems will act as “smart systems” provide in-place analytics that speed discovery and enable businesses to quickly derive meaningful and actionable insights. In his session at @ThingsExpo, Paul Turner, Chief Marketing Officer at...
In his keynote at @ThingsExpo, Chris Matthieu, Director of IoT Engineering at Citrix and co-founder and CTO of Octoblu, focused on building an IoT platform and company. He provided a behind-the-scenes look at Octoblu’s platform, business, and pivots along the way (including the Citrix acquisition of Octoblu).
In his General Session at 17th Cloud Expo, Bruce Swann, Senior Product Marketing Manager for Adobe Campaign, explored the key ingredients of cross-channel marketing in a digital world. Learn how the Adobe Marketing Cloud can help marketers embrace opportunities for personalized, relevant and real-time customer engagement across offline (direct mail, point of sale, call center) and digital (email, website, SMS, mobile apps, social networks, connected objects).
The Internet of Everything is re-shaping technology trends–moving away from “request/response” architecture to an “always-on” Streaming Web where data is in constant motion and secure, reliable communication is an absolute necessity. As more and more THINGS go online, the challenges that developers will need to address will only increase exponentially. In his session at @ThingsExpo, Todd Greene, Founder & CEO of PubNub, exploreed the current state of IoT connectivity and review key trends and technology requirements that will drive the Internet of Things from hype to reality.
Two weeks ago (November 3-5), I attended the Cloud Expo Silicon Valley as a speaker, where I presented on the security and privacy due diligence requirements for cloud solutions. Cloud security is a topical issue for every CIO, CISO, and technology buyer. Decision-makers are always looking for insights on how to mitigate the security risks of implementing and using cloud solutions. Based on the presentation topics covered at the conference, as well as the general discussions heard between sessions, I wanted to share some of my observations on emerging trends. As cyber security serves as a fou...
We all know that data growth is exploding and storage budgets are shrinking. Instead of showing you charts on about how much data there is, in his General Session at 17th Cloud Expo, Scott Cleland, Senior Director of Product Marketing at HGST, showed how to capture all of your data in one place. After you have your data under control, you can then analyze it in one place, saving time and resources.
With all the incredible momentum behind the Internet of Things (IoT) industry, it is easy to forget that not a single CEO wakes up and wonders if “my IoT is broken.” What they wonder is if they are making the right decisions to do all they can to increase revenue, decrease costs, and improve customer experience – effectively the same challenges they have always had in growing their business. The exciting thing about the IoT industry is now these decisions can be better, faster, and smarter. Now all corporate assets – people, objects, and spaces – can share information about themselves and thei...
The cloud. Like a comic book superhero, there seems to be no problem it can’t fix or cost it can’t slash. Yet making the transition is not always easy and production environments are still largely on premise. Taking some practical and sensible steps to reduce risk can also help provide a basis for a successful cloud transition. A plethora of surveys from the likes of IDG and Gartner show that more than 70 percent of enterprises have deployed at least one or more cloud application or workload. Yet a closer inspection at the data reveals less than half of these cloud projects involve production...
Continuous processes around the development and deployment of applications are both impacted by -- and a benefit to -- the Internet of Things trend. To help better understand the relationship between DevOps and a plethora of new end-devices and data please welcome Gary Gruver, consultant, author and a former IT executive who has led many large-scale IT transformation projects, and John Jeremiah, Technology Evangelist at Hewlett Packard Enterprise (HPE), on Twitter at @j_jeremiah. The discussion is moderated by me, Dana Gardner, Principal Analyst at Interarbor Solutions.
Discussions of cloud computing have evolved in recent years from a focus on specific types of cloud, to a world of hybrid cloud, and to a world dominated by the APIs that make today's multi-cloud environments and hybrid clouds possible. In this Power Panel at 17th Cloud Expo, moderated by Conference Chair Roger Strukhoff, panelists addressed the importance of customers being able to use the specific technologies they need, through environments and ecosystems that expose their APIs to make true change and transformation possible.
Too often with compelling new technologies market participants become overly enamored with that attractiveness of the technology and neglect underlying business drivers. This tendency, what some call the “newest shiny object syndrome” is understandable given that virtually all of us are heavily engaged in technology. But it is also mistaken. Without concrete business cases driving its deployment, IoT, like many other technologies before it, will fade into obscurity.
Microservices are a very exciting architectural approach that many organizations are looking to as a way to accelerate innovation. Microservices promise to allow teams to move away from monolithic "ball of mud" systems, but the reality is that, in the vast majority of organizations, different projects and technologies will continue to be developed at different speeds. How to handle the dependencies between these disparate systems with different iteration cycles? Consider the "canoncial problem" in this scenario: microservice A (releases daily) depends on a couple of additions to backend B (re...
The Internet of Things is clearly many things: data collection and analytics, wearables, Smart Grids and Smart Cities, the Industrial Internet, and more. Cool platforms like Arduino, Raspberry Pi, Intel's Galileo and Edison, and a diverse world of sensors are making the IoT a great toy box for developers in all these areas. In this Power Panel at @ThingsExpo, moderated by Conference Chair Roger Strukhoff, panelists discussed what things are the most important, which will have the most profound effect on the world, and what should we expect to see over the next couple of years.
Container technology is shaping the future of DevOps and it’s also changing the way organizations think about application development. With the rise of mobile applications in the enterprise, businesses are abandoning year-long development cycles and embracing technologies that enable rapid development and continuous deployment of apps. In his session at DevOps Summit, Kurt Collins, Developer Evangelist at, examined how Docker has evolved into a highly effective tool for application delivery by allowing increasingly popular Mobile Backend-as-a-Service (mBaaS) platforms to quickly crea...
Growth hacking is common for startups to make unheard-of progress in building their business. Career Hacks can help Geek Girls and those who support them (yes, that's you too, Dad!) to excel in this typically male-dominated world. Get ready to learn the facts: Is there a bias against women in the tech / developer communities? Why are women 50% of the workforce, but hold only 24% of the STEM or IT positions? Some beginnings of what to do about it! In her Day 2 Keynote at 17th Cloud Expo, Sandy Carter, IBM General Manager Cloud Ecosystem and Developers, and a Social Business Evangelist, wil...
PubNub has announced the release of BLOCKS, a set of customizable microservices that give developers a simple way to add code and deploy features for realtime apps.PubNub BLOCKS executes business logic directly on the data streaming through PubNub’s network without splitting it off to an intermediary server controlled by the customer. This revolutionary approach streamlines app development, reduces endpoint-to-endpoint latency, and allows apps to better leverage the enormous scalability of PubNub’s Data Stream Network.