The 2nd edition of the SpainJS conference was held in Madrid last week. On Thursday there were workshops the whole day. Talks and networking happened on Friday and Saturday.

I attended to the workshops and learned a lot in the first one, about memory leaks hunting with Gonzalo Ruiz de Villa (@gruizdevilla). What I remember the most from Gonzalo’s workshop is that timers (setTimeout and setInterval) are by far the most common source of memory leaks. The other thing is that Google Chrome has excellent built-in tools to watch for memory leaks. The memory consumed by the application should not grow as time passes, it should be stable. The online exercises prepared by Gonzalo are really good and very clear. It’s worth studying them.

I missed the other workshops as I had to work a lot, but that is another story. All I can say is that people from the other workshops were very nice. I found the time to have a quick chat with them.  Now let’s talk about the actual conference:

This year’s venue wasn’t as nice as last year’s one, because last year it was in the middle of the park. Also the sound wasn’t the best when speakers were on the stage. But everything else was very good in my opinion. In my experience this kind of small things happen when the conference is cheap. But I think they didn’t have a negative impact on the conference. The organization was very good, the networking was excellent and the contents were brilliant. I will definitely attend next year if I can make it. I left the conference before the end as I was flying in the evening, so I missed the last 4 talks, which according to twitter were very appreciated by the audience.

These are the things I remember from the talks I liked the most:

  • From Douglas Crockford: the pragmatic approach when designing languages. The advises/hints in his slides were very good. And the reflection on the fact that developers choose languages because of fashion rather than professionalism. Smalltalk had more convenient design than C++ but still C++ got more popularity among developers. A very similar talk by Crockford can be seen online.
  • From Martin Naumann: proof things by yourself, don’t just believe everything people say about tools and frameworks, and choose whatever that works better for you.
  • From Robert Nyman: first of all, his sense of humor. Very nice talk. The guys at Mozilla are working hard to facilitate Internet access to people in the third world. FirefoxOS can run in really  cheap devices and it’s totally web based. Last week Telefonica started selling a new cheap phone with FirefoxOS. Looks like they (Mozilla) are working towards a better world. And I really love the idea. I’ll see how can I contribute with the Mozilla Fundation.
  • From Tomas Perez & Jose M. Perez: localStorage has it’s drawbacks and it’s not a silver bullet. You’ve got to be defensive when accessing keys.  iFrames along with window.postMessage are sill good to communicate different applications, and sometimes, the only choice.
  • From Reg Braithwaite: programming languages can be used poorly or professionally. He demonstrated how a very complex problem can be solved with JavaScript in the browser, rather than with a big cluster of computers. Reg is author of the fabulous book JavaScript Allonge. My friend @pasku1 told me about this book some months ago and I am already using this style in my JavaScript. I am very happy with it. I am no longer using the “new” keyword in JavaScript and I have no more problems with the “this” keyword. I totally recommend the book.
  • From Peter Christensen: there are JavaScript APIs to talk to hardware devices like Arduino or Rasberry pi, like Johny Five. And there are people (makers) doing all kind of original and crazy projects all over the world.
  • From Axel Rauschmayer: if you don’t want to have trouble with JavaScript, respect the Liskov Substitution Principle. Don’t ask for types in your functions, to  do different things based on types. Also notice that on iframes, the rules change and it doesn’t work the way you expect. The slides are a very good summary. They are here.

I met a lot of interesting people and also good friends. The lunch breaks and the night party were really good to meet people and talk. Friday’s party was awesome, indeed. I planned to leave the party at 10pm, as I had a few things to do,  but I eventually left after midnight because of all the interesting conversations that were there.

Let’s see if people who attended to the other sessions write some opinions about th em.

This post will be updated as I gather and remember more information about my experience.

Thanks again to Israel Alcazar, Enrique Amodeo, Lorena V. Perez, Sam Lown, Fernando Martinez,  and all their colleagues who organized SpainJS. Very well done guys, excellent conference.

Pictures here