At EclipseCon 2010, Heiko Behrens of itemis AG, presented how to build application using a model driven approach at EclipseCon 2010. Using a model driven approach, Behrens was able to create an iPhone application using iPhonical, which is a Domain Specific Language based on Xtext for developing iPhone applications.

Hieko Behrens and Peter Friese demonstrated an iPhone application for the EclipseCon NASA mars rover challenge which controls a robotic rover over simulated mars landscapes.

Behrens had these thoughts to share on iPhonical and his EclipseCon presentation:

Q: Can you build an entire functional iPhone application using a model driven approach?

Heiko Behrens: Yes! In fact, I built a complete iPhone application during my 12 minute lightning talk here at EclipseCon. That application is able to browse the corporate blog of itemis as well as an index of itemis speakers and talks here at EclipseCon. From any screen you can jump to related bits of information. Everything is being loaded on demand and behaves like every other native application on the iPhone.

Q: What is the benefit of using a Model Driven approach to iPhone development?

Heiko Behrens: For me, this particular demo app represents an important part of many apps you can find in the store today. Most of these  ”data-driven” apps – be they facebook, tripit, flicker, or any other web connected application – they all need to load, store, cache and work with data in various data formats. With MDSD you can easily describe these parts of an application without implementing all the technical details. Since its output integrates well with manually written code you can constantly evolve your data model while concentrating on the UI part of your application. And, if you are interested in a rapid prototype only you can simply generate the UI from your model, too.

The cool thing about this model and its editor is the semantic value you create. While typing it literally knows you are describing a filename, an URL or a call to another view and it can highlight errors such as missing files, invalid web ressources or cycles in your navigation path. This is something your general-purpose programming language (here: Objective-C and Xcode) simply cannot do for you. You will notice potential errors only at runtime when your app crashes or stops with an empty screen.

Q: At a high-level, what are the basics of iPhone application development using a model-driven approach?

Heiko Behrens: During my presentation I demonstrated the use of a domain-specific language (DSL) based on Xtext to write down the program in a language particular designed for describing mobile applications. Think of it as an super easy programming language: the entire demo app fits in just 120 lines. Every change you make instantly affects the generated output (in this case 16 files with a few hundert lines each) of a ready-to-use iPhone project. At any time you just hit “run” to give it a test-drive.

More Resources

Heiko Behren’s EclipseCon 2010 Presentation

iPhonical on Google Code

EclipseCon 2011

Heiko Behren’s Blog