Ubuntu 18.04 uses systemd to manage services. There are basically two commands for listing all services and manipulating the state...
If a model inherits from others or uses many concerns / traits, it might be hard to see in the code...
If you want to prevent that two processes run some code at the same time you can use the gem...
# Basic HTML example # Javascript API (notable methods and properties) video = document.querySelector('video') video.play() video.pause() video.load() // Reset to the beginning and...
Speaker today is Henning Koch, Head of Development at makandra. This talk will be in German with English slides.
This seems to be obvious, but you can expect Rake tasks to be called in RSpec. it 'deletes all Users...
With puma you can have concurrent requests. There are two concepts on how Puma can handle two incoming requests: Workers...
Embedding videos on a website is very easy, add a tag to your source code and it just works...
Code comments allow for adding human readable text right next to the code: notes for other developers, and for your...
Heads up: transparent is not a real color, but black with 0% opacity. In transparent gradients, this adds some gray...
We can use ActiveRecord's where to add conditions to a relation. But sometimes our condition is not on the...
You can use the CSS property mask-image to define an "alpha channel" for an element. E.g. to let an...
PostgreSQL and ActiveRecord have a good support for storing dynamic attributes (hashes) in columns of type JSONB. But sometimes you...
Debugging image color profiles is hard. You can't trust your eyes in this matter, as the image rendering depends...
SimpleScreenRecorder I recommend simplescreenrecorder, it produces an adequate output with only a few clicks. The audio recording contained some...
A primer on vector graphics For rastered image formats like JPG or PNG, each pixel is basically drawn on a...
There is a practical short list for valid/invalid example email addresses - Thanks to Florian L.! The definition for valid emails...
Rails uses a CSRF token in forms and AJAX requests to verify a user request. Internally it compares the injected...
Normally, Rails handles encryption and signing of cookies, and you don't have to deal with the matter. Should you...
When using Chrome for Selenium tests, the chromedriver binary will be used to control Chrome. To debug problems that stem...
The main benefit of our convention to prefix commits by their corresponding Pivotal Tracker ID is that we can easily...
Example (broken in IE): flex: 0 1 calc(50% - 20px) Workaround: flex-basis: calc(50% - 20px) flex-grow: 0 // Default...
Within a Flexbox layout, there are multiple CSS attributes that may affect a child's basis (the initial width before...
When an AJAX request raises an exception on the server, Rails will show a minimal error page with only basic...