Month: March 2017

Chris talked about Elm, which he subtitled “JavaScript for people who like Haskell not JavaScript”.

However, he immediately explained that Elm is not like Haskell, and isn’t intended to be compared to Haskell, and that it is aimed at JavaScript developers not Haskell developers, and avoids the community avoids using Haskell terminology. This is intended to help increase the uptake of the language.

However, it is a pure functional language, and does look quite Haskell-ish: for example, it supports pattern matching, immutability, and so on. It is event-driven.

One thing it concentrates on is having good error messages. It will even do things like identify references to variables that don’t exist, and suggest what you might have intended. It’s also helpful that there’s an Elm plugin for IntelliJ IDEA.

Like most modern JavaScript frameworks, it uses a virtual DOM, to make it faster.

There is a time-travelling debugger, which is a very cool feature, but Chris didn’t use it in practice.

It has automatic semantic versioning, so it updates the major version automatically when existing signatures change. However, the Elm language itself has changed significantly in minor versions, so you can’t depend on code for older Elm versions being compatible. This was frustrating for working in the language – finding older libraries that hadn’t been updated, and older examples that were out of date.

You can incrementally rewrite an existing JavaScript codebase to Elm, on a file-by-file basis. Chris wasn’t sure how compatible Elm output is with older browsers.

There are currently no books (although there will be later this year). There is a “try elm” site that is good.

It’s primarily aimed at interactive UIs, and games.

Chris’s sample Elm code is at http://nespera.github.io/elm-slide/. However, he hasn’t actually completed the game, because it’s too hard.

Then, Loic talked about Punishment Driven Development. He talked about reasons why companies punish people, and the effects of that punishment. He described the importance of understanding why people are behaving as they do, and that sometimes you may need to change your own behaviour to work with them in order to achieve your objectives. Then, he talked about the axioms of Punishment Driven Development, and contrasted them with People Driven Development.

At the dev meeting this week, we talked about the PHP framework Laravel, about Slack integrations, and about automating Android phones with Tasker.

Bart gave a presentation on Laravel. It’s an MVC framework for PHP, that bills itself as “The PHP Framework for Web Artisans”. It makes extensive use of “artisan”, a command-line code generation tool for generating models, view templates, etc. It supports various features familiar from MVC frameworks in other languages, such as database migrations, programmatic definition of routes, and ORM.

We’re not using Laravel, and we’re not likely to be using it for any client projects, but we are using PHP for some infrastructure things like our website.

Then we discussed Slack integrations that we are finding useful, and Slack integrations that we wish we did have. We have a webhook-based Gitlab integration, which sends a message whenever code is pushed to a Gitlab repo – this is useful for low-traffic repositories like document repos, but less useful for code repos. We have a Jenkins CI integration set up as part of our standard Jenkins script, which sends messages on success/fail of the build. This is more convenient than the email notifications we also have set up. For the client projects that use it, we have a Bamboo integration that works similarly. We have also tried the Trello bot, but didn’t find it useful.

Other Slack integrations that we thought might be useful were:

• A wiki search bot, for searching our internal wiki
• A JIRA slack bot for creating and tracking JIRA tasks
• A cake bot, for working out whose responsibility it is to provide cake or cheese for our Cheese/cake Mondays
• An uptimerobot bot, so downtime notifications can be sent to Slack as well as email
• A password bot, for reminding us of passwords for our infrastructure

We also discussed the usage of Hubot at Github, which they use to automate all of their infrastructure. There is an Open Source version of Hubot available.

Joe talked about Tasker, an automation app for Android. Joe originally installed this after receiving a parking ticket in the Park and Ride. His use case was to detect when his car had stopped moving, so he could then automatically launch the Park and Ride app to pay for parking.

Tasker allows you to write small scripts for managing Android, without having to write a full Android app. For example, “I can see this cell tower” therefore “trigger these actions”. “I am plugged into power, and can see the car’s bluetooth” so “launch SatNav and turn off wifi” – and then when moving out of that state, “check the GPS and launch the Park and Ride app if at the car park”. “On receiving a text message with a particular text”, “turn volume up to maximum and play music”, in case the phone is lost. We also briefly discussed Llama, which is a similar Android automation app, although less sophisticated.