Peter Hilton - Play for Scala: Covers Play 2

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Change comes in waves. Youre reading this book because you want to be part of the next wave of change in software development. Big data, mobile, JavaScript-based web apps, RESTful services, functional programming, and the real-time web are propelling us into a new era. Every new era is accompanied by a new set of tools, which keen developers wield to build amazing things. Play Framework and Scala are the tools youll use to ride the approaching wave and build the next amazing thing.

When surfing a new wave, its best to go along with experts in the surf break. They can tell you when and where to go, what places to avoid, and how to have a smooth ride. Peter Hilton, Erik Bakker, and Francisco Canedo are your experts in the Play and Scala break. They all have extensive experience building amazing things with these tools. Before most of us even saw the wave, they were riding it and building the tools the rest of us need. Play for Scala is your guide to this new surf break.

Whether youre just getting started with Play or building a real-time app with iteratees, this book will guide you well. The authors have done a great job of providing the right level of detail. They havent obviated the need to do some self-exploration, Google searches, and check Stack Overflow. Yet their code examples are complete and well explained. Its hard to write a book that fits the needs of novices and experts, but somehow Hilton, Bakker, and Canedo pulled it off. Play for Scala has exactly the right verbosity level.

Now comes the fun part. The wave is approaching, so grab your tools, paddle out with your expert guides, and surf your way into the next era of software development!

J AMES W ARD
D EVELOPER A DVOCATE AT T YPESAFE
WWW.JAMESWARD.COM

We were early adopters of Play and saw it gain popularity among a wide variety of Play developers. Now its time for Play to go mainstream.

When I first tried the Play 1.0 release in 2010, I was struck by how simple it was. Having tried many different web frameworks, it was a refreshing change to find one that used what I already knew about HTTP and HTML (the web) instead of being based on non-web technology. In fact, the developer experience was so good, it felt like cheating.

I was also impressed by how finished Play seemed: this was no early experimental release. Many open-source projects adopt the release early, release often philosophy, which means a first public release is a version 0.1 thats more of a prototype, vision statement, and call for participation. Play, on the other hand, started at version 1.0 and had clearly already been used to build real applications. Zenexity used Play on customer projects for some time before releasing version 1.0, and it wasnt just Java developers using Play; web developers had been using it too. You could tell.

The idea that Play would be for web developers, not just Java developers, turned out to be the most important of goals because of the consequences for the frameworks design. After years of struggling with frameworks that make it hard to make nice HTTP interfaceseven at the simplest level of building web applications whose URLs werent uglyhere was a framework that actually helped. Suddenly we were running with the wind.

At first, we figured that this was a small framework for small applications, which was nice because it meant that we wouldnt have to use PHP any more for easy problems. What actually happened was that each Play application was bigger or more complex than the last, and was another chance to get away with not using Java EE. We didnt just get away with using Play; by the time Play 1.2 was released in 2011, we started to get away from having to use Java EE, and JSF in particular, which had become the new JSP for me (only more complex).

At this point, it only seemed fair to help more Java web developers start using Play. And then there was Scala.

For us, Play 2 came at a time when we were discarding more than just writing web applications with JSP or JSF. We were also starting to use Scala instead of Java. The Play early adopters and the Scala early adopters then found each other, and we realized that the combination is even more compelling.

When we started talking to people about moving on from Java EE, we discovered that people can get upset when you suggest that the technology that theyve devoted a significant portion of their career to mastering is an architectural dead end, and that its time for something new. Moving on is hard, but inevitable if you dont want to be the next COBOL programmer. You know youre a junior developer when none of the things on your CV have become legacy yet.

In our business, its important to be ready for something new. As with many kinds of beliefs, youre going to be happier if your technology choices are strong opinions, loosely held. The arrival of Play 2 was clearly not just a new version; it was a challenge to take what wed been doing to something more mainstream.

At Lunatech, technology adoption follows a kind of progression, starting from a single enthusiast and initial experiments, moving on to low-risk use by a few people, and finally to full adoption on development projects for external customers. At each stage, most technologies are discarded; Play and Scala survived this natural selection in the technology space and are now used by most of us on nearly all of our new projects.

Having made this kind of change before, we understand that switching to Play or switching to Scala can be a big step, especially if you do both at the same time. We were open to the idea that something more than a few blog posts and some documentation was needed, and we came to the surprising conclusion that the world needed another computer book.