During the second week of February, I ran my (approximately) annual public Perl training courses in association with FlossUK. Things were organised slightly differently this year. Previously we’ve run two two-day “general purpose” courses – one on Intermediate Perl and one on Advanced Perl. This year we ran four courses, each of which were on a more specific technology. There were one-day courses on Moose, DBIx::Class and testing and a two-day course on web development.

Class numbers weren’t huge during the week. We had about six people on each of the days. That’s a large enough class to get plenty of discussion and interaction going but, to be honest, I’d be happier if we got a few more people in. The attendees were split pretty much down the middle between people who working for commercial organisations and people who worked for universities. I’m sorry to report that there were no women booked on any of the courses this year.

As is often the case on these courses most of the attendees had been using Perl for a long time and were pretty comfortable with some quite advanced Perl features. But, for various reasons, they simply hadn’t had the time to investigate some of the newer Perl tools that would have made their lives much easier. I often get people at these courses telling me that the best thing about the course is just having a day set aside where they can try out cool new technologies that they have heard of without the worry of someone calling them away to deal with some vital production issue (this, incidentally, is also why most trainers far prefer off-site training courses).

We started on day one with Moose. Most of them had used “classic” Perl OO techniques and were well aware of how baroque that can become. They were therefore very interested in the more declarative approach that Moose gave them. By the end of the day our Dalek class was using roles, traits, type coercion and many other useful Moose features.

Day two was DBIx::Class. Everyone was using a database of some kind and all of them were using DBI to interface to their database. I really enjoy introducing people like that to DBIx::Class. Once they’ve run dbicdump and have generated classes for their own databases most people’s eyes light up when they see ho much easier their code can become. As a bonus, this class contained no-one who needed to be persuaded of the benefits of defining foreign keys in your DDL and making use of referential integrity checks.

The third day was testing. I mean, it was about testing – not that it was particularly difficult. The class was full of people who knew the benefits of testing but who were maintaining large codebases with hardly any (in some cases no) tests. In the morning we looked at how simple the Perl testing framework is, did a quick survey of some useful testing modules on CPAN and even looked at writing our own testing modules. In the afternoon we expanded that to look at mocking objects and Test::Class. I think the most popular sections were when I introduced Devel::Cover and the concept of continuous integration. I encouraged them to write even just a few tests and to hook their test suite up to a highly visible Jenkins job. If you make your lack of test coverage obvious, then other people in the team can be encouraged to help improve it out of sheer embarrassment.

Thursday was the first day of the two-day course on web development. The first day concentrated on PSGI and Plack. We looked at what they are and how they make web development simpler. We also looked at ways to run non-PSGI applications in a PSGI environment in order to benefit from PSGI’s advantages. This seemed to really engage a couple of people in the class who used a practical session at the end of the day to start working to get their own legacy apps running under PSGI. I was particularly pleased when, the next morning, one of them told me that he had continued to work on the problem overnight and that he had got a huge system that used a combination of CGI and mod_perl working under PSGI. He was really happy too.

On the final day, we looked at web frameworks in Perl. The morning was all about Dancer2. We started by building a small web app and I showed them how simple it was to interface with a database and to add authentication to the system. Later on we added an API to the app so that it could return JSON or XML instead of web pages. Early in the afternoon, I took that a step further and demonstrated Web::Machine and WebAPI::DBIC. The rest of the afternoon was about Catalyst. We built another app (similar to the Dancer on from the morning) using the standard Catalyst tutorial as a basis. I’m not sure how well this went, to be honest. Following the simplicity of Dancer with the (relative) complexity of Catalyst wasn’t, perhaps, the best advert for Catalyst.

But, all in all, I think the week went really well. I sent a small but enthusiastic group of people back to their offices with a new interest in using Modern Perl tools in their day-to-day work. And, perhaps more usefully, I think that many of them will be getting more involved in the Perl community. A few of them said “see you at the LPW” as they left.

I’m running a half-day workshop on Modern Perl Web Development at the FlossUK Spring Conference next month. Other than that, I don’t have any public courses planned. But if you think that your company would find my training useful, then please get in touch.

Also published on Medium.