murb ♥︎ ruby

It may not be the fastest programming language, nor is it the most popular language when it comes to the numbers game, but how can you not fall in love with:

 10.times { print "Hello!" }

(instead of something like for(var i=0; i<10; i++){ console.log("Hello!"); })

Do things with sets like:

["a", "b", "c"] & ["b", "c", "d"] # gives you ["b", "c"]
[1,2,3] + [4,5] # gives you [1,2,3,4,5]
["a", "b", "c"] - ["b", "c", "d"] # gives you ["a"]

Or (with a little (opinions differ on this one ;)) help of Rails):


That offers you exactly what you would think it would return: the date of 10 days ago.

And no ;’s, only brackets when absolutely needed, everything is an object…

Yes, it’s actually a language a human might understand, and still: it is pretty powerful, powering some of the most popular sites on the web, like AirBnB, Shopify, Basecamp (they’re the creators of Ruby on Rails), Github, Kickstarter, Twitch, Strava and many more (most of the full stack projects I did & do are using ruby).

De eerste vier zaken op een (macOS) ontwikkelmachine voor beginners

An article, posted 12 days ago filed in , , , , , , , , , , & .
  1. Update eerst naar de laatste versie van ’t OS, Mojave. Je kunt deze gratis downloaden in de App store, zie upgrade instructies voor Mojave.
  2. Installeer homebrew … macOS Terminal (zeg maar de Command Prompt van de Mac) vind je door Cmd+Spatie in te drukken en vervolgens "Terminal" te zoeken (meestal vind je die al na de eerste paar letters). Vervolgens de regel invoeren (kopiëren & plakken) die de website vermeld. Soms moet je extra dingen installeren; het script zal je daar doorheen leiden. Overigens, dat commando, Cmd+Spatie, opent wat Spotlight heet, ik vind dat de gemakkelijkste manier om programma’s te starten.
  3. Install Docker for mac (je hebt hier tegenwoordig helaas een account bij DockerHub voor nodig). Dit download een DiskImage, sleep het programma naar de programma’s map (zoals het image waarschijnlijk ook al aangeeft in de achterg…

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Global variables in Rails

An article, posted 27 days ago filed in , , & .

A quick note, because I was using the wrong search terms. If you want to share e.g. the current user of an app with a model you can now (since Rails 5.2) use a model inheriting from ActiveSupport::CurrentAttributes. Before you were required to pass this current user explicitly or find another way to access state.

Note that this can either be a good thing or a bad thing (tl;dr: thread-local global state makes apps unpredictable)

And even the docs warn against abusing this feature. Powerful tools can come with dangerous consequences :) Global variables are immensely powerful. Use with care. I'm not even sure if I'm going down this path…

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Revisiting taming ruby's memory bloat meta-edition

An article, posted about one month ago filed in , , , , & .

There are a lot of things that I don't understand. One of these things is how memory management really works. Memory management is hard, and even though I use languages that do garbage collecting by themselves, long running ruby apps seem to run out of memory after n number of days. Even the pro’s find it quite hard. While I previously resetted the failing app every now and then, I was triggered by Mike Perham’s (creator of Sidekiq) post: “Taming Rails memory bloat”.

When you start searching for the memory bloat problem, you'll find several directions. The easiest is changing a global variable which changes the number of “arena’s” where memory allocation takes place (note: I’m in no position to explain all this, please follow the references). The fanciest, however, seems to be changing the memory allocator from glibc's default 'malloc' to jemalloc. See for example [this](…

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Prometheus for slow stats

An article, posted about 2 months ago filed in , , , , , , , & .

Prometheus is a statistics collecting tool that originated from SoundCloud. Designed to be used in high performance environments, it is build to be blazingly fast. Hence, the client typically is expected to be blazingly fast as well, gathering and presenting data within nanoseconds. For Ruby on Rails applications however this has lead to an unresolved issue with the Prometheus ruby-client when the same application is forked (typical for Puma, Passenger and other popular ruby-servers). The Prometheus client collects data within its own fork before serving it to the exporter endpoint. This can or cannot be a problem. When you measuring response times, running averages from a random fork may be good enough. However, when you're also counting data over time you're having separate counters in …

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Be a (unit-testing) minimalist

An article, posted 6 months ago filed in , , , & .

Still (2013) a great talk by Sandy Metz on testing, and how to do it right, without getting too theoretical. While this talk is on ruby, and it uses a Rails framework for testing, it really is applicable to any other language (only the syntax will probably be a wee bit shittier ;))

Watch Rails Conf 2013 The Magic Tricks of Testing by Sandi Metz on YouTube

(and while unit-testing is between brackets, in general, being a minimalist when writing code really is a good idea)

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JavaScript & Rails: a `webpacker` evaluation

An article, posted about one year ago filed in , , , , , , , & .

Webpacker is still opt-in for new Rails projects. But this might change. The JavaScript ecosystem is moving fast and new JavaScript frameworks are pushing customer’s expectations to higher levels. To use these frameworks with your Rails app, you had a few options:

  • Include the JavaScript manually; which requires you to manually copy the files in place
  • Use a gem-wrapper to to install the JavaScript library; but this required quite some maintenance on the Gem-author’s side.
  • Try to mangle npm or yarn into the asset pipeline yourself
  • Use Rails Assets (an automagic Gem-wrapper)

A small praise for Rails Assets

I have been using the past few years to keep my JavaScript dependencies up to date. It thought it was smart solution; instead of requiring individual developers to maintain Gem-wrappers, Gem wrappers are created on the fly by It was smart and light weight on the developers side and worked perfectly with the Rails' Asset p…

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PHP revisited

An article, posted more than one year ago filed in , , , , , , , , & .

I've been able to stay away from PHP-based projects for quite some time. Until recently. I needed a small API. The idea was that the API would be transferred to a relatively old server that had been running stable for years and the client didn't want to risk installing additional script interpreters on it. It might even have been my own suggestion, it would be a really small API, requiring no special changes on an already operational 24x7 managed server. On top of it I'd write a modern style front-end, running entirely in the browser.

Of course the API that was intended to be simple got a bit more complex. I wanted the API to output clean JSON messages, which required some data mangling, as data was stored in CSV's, TSV's, and misused XML-files or only accessible through crappy soapy API's. So what does present-day (well, the Red Hat PHP version I was able to use is still in 5.x-series) PHP look like? TL;DR: sometimes it was definitely ugly, but at I can happily live with the cod…

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Unit-testing your front-end code in a Rails project: Yarn, Tape & Rails

An article, posted more than one year ago filed in , , , , , , & .

I like Rails, but one thing that Rails falls short in is Javascript dependency management.

While Rails Assets, a proxy that allows for listing Bower packages in your Gemfile makes managing front-end libraries good enough for most front-end work, RailsAssets itself is mainly addressing asset management; it doesn’t allow for integrated management of additional development tools and binaries, useful for e.g. JavaScript-testing (besides the fact that Bower is kind of considered to be deprecated these days).

There are different ways of bundling Javascript, but since Rails 5.1, yarn is the defacto choice for Rails.

Installing Yarn

You can install yarn either trough npm npm install -g yarn, or if you’re on a mac, using homebrew: brew install yarn. I chose the latter.

To prepare your rails project run rails yarn:install.

Add tape for testing JavaScript & Coffeescript

There are [different testing fram…

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Eat your own dogfood

An article, posted about 2 years ago filed in , , , & .

Just a small note that I've made some improvements to my SocialLinker-gem lately and while I've been using it on a few sites already, I wasn't using it on my very own blog. Today I found some time to change exactly that: you've got to eat your own dog food. If you want to have a taste of it: murb/social_linker (if you're a ruby-dev) or just click the share icons below :)

Image CC-licensed BY: Sh4rp_i

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ActionCable and authentication with Devise (2/2)

An article, posted more than 2 years ago filed in , , , , , , & .

This is a short follow up on the previous article in which the ActionCable basics were explained. We can now add some level of authentication. Authentication is a bit harder than simply registering some before_action’s, but it is perfectly doable, especially if you've survived the previous tutorial.

From the official Action Cable guide we can simply reuse the full connection.rb template:

module ApplicationCable
  class Connection &lt; ActionCable::Connection::Base
    identified_by :current_user
    def connect
      self.current_user = find_verified_user
      def find_verified_user
        if current_user = User.find_by(id: cookies.signed[:user_id])

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Getting started with Rails ActionCable (1/2)

An article, posted more than 2 years ago filed in , , , , , , & .

As the lead developer at I wanted to try the new Rails ActionCable technology for a new feature: shopping lists. The idea is that you can walk in a store or on a market, mark an ingredient as checked when you add it to your (physical) basket and continue shopping. ActionCable can make the experience nicer because it, based on WebSockets, allows for real time notifying other viewers and editors of the same shopping list. No more shouting around in the supermarket: I’ve got the milk! Sure, nothing essential, but I needed an excuse ;)

(Note that we recently migrated from Rails 4, so not everything was in place in our app, just ignore the bits Rails already made for you; everything has been tested with Rails

Getting the basics right

To start: You need a web server that can open multiple threads, so if you’re still using Webrick in development (which can’t rece…

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An article, posted almost 3 years ago filed in , , , , , , , , , , & .

I had a few projects that I thought could use some share 'buttons', but I didn't like to include the JavaScript loaded and privacy invading share buttons that the networks try to sell you by default. Neither did I like to concatenate the links with all variables required for each project… so I wrote a small rubygem on a back and forth train trip (#ilovetrains ;)): social_linker.

The idea is that you share something about a certain subject, hence you initalize the SocialLinker::Subject and then you'll be able to generate share links from it:


How it works

Initialize the subject with enough material to generate links from, such as the page's url, maybe the media url (mainly for Pinterest type-shares), a description, tags etc.

For example, initialize the SocialLinker::Subject as follows:

social_linker_subject = SocialLinker::Subject...

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Tag descriptor


An article, posted almost 3 years ago filed in , , , & .

Making Ruby + Rails portable for the Windows platform (in other words, work without command line unfriendly installers). Updates below, code and readme on Github

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Tag descriptor

The `workbook`-gem

An article, posted almost 3 years ago filed in , , & .

workbook is simple ruby framework for containing spreadsheet like data in a datastructure that is known to most programmers: the (multidimensional) Array.


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