Joachim Haagen Skeie - Ember.js in Action

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Since 2006, Ive worked with the development of web applications in one form or another. I started out writing a web application for Norways largest retailer, which was based on JavaServer Pages (JSP) and later migrated toward JavaServer Faces (JSF). At the time, these technologies were great, and they served their intended purpose. Back then (before Ajax became widely used), the request-response cycle of HTTP demanded that most of the logic be put on the server side and that the server deliver complete markup, scripts, and style sheets to the browser on every request.

Even though these server-side approaches to writing web applications did their job, issues arose whenever state was a concern. Because the server is required to do the bookkeeping for all the logged-in users, managing state quickly becomes a difficult and memory-hungry task. How do you deal with users opening multiple tabs in your application and switching between them? How do you persist your session data when you want to scale the service across multiple (virtual) machines? How can you easily scale out horizontally in a consistent fashion if you have user-state stored on the server side?

As I started working on the open source project Montric (named EurekaJ at the time), I quickly decided that if I wanted to scale the application horizontally without requiring a separate session cache, Id need to invest in learning one of the JavaScript frameworks that had started to gain momentum and popularity.

I assessed multiple frameworks and built prototypes in both Cappuccino (www.cappuccino-project.org) and SproutCore (http://sproutcore.com). Although Cappuccino had more complete tooling and promised a detailed and good-looking user interface for my application, I chose SproutCore because it enabled me to use my existing skills, while promising an easier integration with third-party libraries. SproutCore also offered powerful views, which act as components that can be combined into a fully functional web application. Coming from a component-based, server-side framework world, these features made me feel at home with SproutCore. But despite this initial delight, I discovered that integrating SproutCore with third-party libraries wasnt as easy as I had anticipated.

When the SproutCore team was acquired and the momentum of the framework slowed down, the SproutCore community began to shift. Work on SproutCore v2.0 was well underway, but the gap between the original SproutCore and what was to become SproutCore v2.0 was widening. As a result, Ember.js was born as a fork of SproutCore.

Ember.js promised a framework that was thoroughly rooted in the technologies that drive our web experience, enabling youas a developerto use the skill set that you already have to develop JavaScript applications. Ember.js doesnt abstract or hide the details of your JavaScript, HTML, or CSS code, but instead it embraces these technologies to lift them up into the twenty-first century.

Needless to say, I followed along with Ember.js and decided to rewrite EurekaJs front end with Ember.js. In the process I renamed the project Montric (http://montric.no). Ive been on the Ember.js roller coaster ever since. Being part of the prev1.0.0 Ember.js community had its highs and its lows. With constantly changing APIs, and concepts being rethought and revisited on what felt like a weekly basis, the lows have mostly been ironed out, leaving only the highs. Deciding to write a comprehensive book about Ember.js in its pre v1.0.0 days undoubtedly exaggerated the lows in my mind.

As Im writing this, Ember.js v1.2.0 is out, the API is stable, and the project is healthy and growing. Ember.js has become an awesome framework that lets you push the envelope on the applications you build for the web.

This book is the most comprehensive and cohesive writing Ive done to date, and it has been an experience with a steep learning curve. Crafting and writing this book has been an extremely humbling, difficult, and educational experience.

I wish to thank the Manning team for being willing to publish a book about Ember.js and for pushing to get the book realized as the story/journey that youre about to embark on. I would especially like to thank development editor Susanna Kline for putting up with my many missed deadlines and endless Skype questions, and for always giving great feedback on needed improvements. I also would like to thank the team of copyeditorsLianna Wlasiuk along with Rosalie Donlon, Sharon Wilkey, and Teresa Wilsonwho caught and fixed an embarrassing number of spelling and grammar mistakes throughout the text. Thanks also to proofreader Melody Dolab, compositor Marija Tudor, and project managers Mary Piergies and Kevin Sullivan.

The reviewers also made sure that the book remained on point and relevant during the various stages of its development, and Id like to extend my gratitude for their work along the way. Thanks to Benot Benedetti, Chetan Shenoy, Dineth Mendis, Jean-Christopher Remy, Leo Cassarani, Marius Butuc, Michael Angelo, Oren Zeev-Ben-Mordehai, Philippe Charrire, Richard Harriman, and Rob MacEachern. Finally, thanks to technical proofreader Deepak Vohra for his careful review of the manuscript shortly before it went into production.

I wish to extend a special and huge thank you to my beautiful wife, Lene, and my two amazing children, Nicolas and Aurora. Lenes support and understanding have been incredibly important during the writing of the book, especially as it consumed a lot of my spare time during evenings and on weekends. Knowing that your family is safe, secure, and happy is of utmost importance when deciding to prioritize your spare time elsewhere.