CarrierWave: Default Configuration and Suggested Changes

Posted About 3 years ago by Dominik Schöler.

CarrierWave comes with a set of default configuration options which make sense in most cases. However, you should review these...

Running old ImageMagick versions in a Docker container

Posted About 3 years ago by Michael Leimstädtner.

If your project depends on an old version of ImageMagick that you can no longer install in your system, you...

Some tips for upgrading Bootstrap from 3 to 4

Posted About 3 years ago by Florian Leinsinger.
getbootstrap.com

Recently I made an upgrade from Bootstrap 3 to Bootstrap 4 in a bigger project. Here are some tips how...

Git: Parsing large diffs as a human

Posted About 3 years ago by Michael Leimstädtner.

I just finished migrating a project from the Asset Pipeline to Webpacker, this is what my diff to master looks...

Git diff: Deemphasizing code that was only moved around

Posted About 3 years ago by Dominik Schöler.

In long diffs, it can become impossible to spot small changes in larger blocks of moved code. This may be...

Capybara: Running tests with headless Chrome

Posted Over 3 years ago by Henning Koch.

Headless Chrome is a way to run the Chrome browser without a visible window. Configuring Capybara Configure the Capybara driver...

A few recent CSS properties

Posted Over 3 years ago by Dominik Schöler.

Feature Queries (Edge 12+): Similar to @media queries, @supports blocks can be scoped to browsers that support a given declaration...

CSS variables aka CSS Custom Properties

Posted Over 3 years ago by Dominik Schöler.

CSS variables are very different from preprocessor variables. While preprocessors use variables to compile a static piece of CSS, CSS...

Carrierwave: How to migrate to another folder structure

Posted Over 3 years ago by Florian Leinsinger.

A flat folder structure can be cool if you have only a few folders but can be painful for huge...

Useful Ruby Pathname method

Posted Over 3 years ago by Niklas Hä..

If you have a Ruby Pathname, you can use the method :/ to append filepaths to it. With this method, Ruby...

Vortrag: Content Security Policy: Eine Einführung

Posted Over 3 years ago by Tobias Kraze.

CSP hat zum Ziel einen Browser-seitigen Mechanismus zu schaffen um einige Angriffe auf Webseiten zu verhindern, hauptsächlich XSS...

The HTML5 video element

Posted Over 3 years ago by Dominik Schöler.

# Basic HTML example # Javascript API (notable methods and properties) video = document.querySelector('video') video.play() video.pause() video.load() // Reset to the beginning and...

Testing for XSS in Markdown Fields

Posted Over 3 years ago by Stephan Plöderl.
github.com

If you render markdown from user input, an attacker might be able to use this to inject javascript code into...

Legacy CarrierWave: How to generate versions with different file extensions

Posted Almost 4 years ago by Michael Leimstädtner.

We use CarrierWave in many of our projects to store and serve files of various formats - mostly images. A common...

Video transcoding: Web and native playback overview (April 2020)

Posted Almost 4 years ago by Michael Leimstädtner.

Embedding videos on a website is very easy, add a tag to your source code and it just works...

Colorful output for several linux command line tools: grc

Posted Almost 4 years ago by Judith Roth.
github.com

Because colors improve readability so much. On Ubuntu 18.04 you can install it with sudo apt install grc

HTML/CSS: "transparent" is not a color

Posted About 4 years ago by Dominik Schöler.
developer.mozilla.org

Heads up: transparent is not a real color, but black with 0% opacity. In Safari, this makes e.g. gradients between...

Bash: How to use colors in your tail output

Posted About 4 years ago by Judith Roth.

Sometimes it's nice to have some coloring in your logs for better readability. You can output your logs via...

Letting a DOM element fade into transparency

Posted About 4 years ago by Henning Koch.

You can use the CSS property mask-image to define an "alpha channel" for an element. E.g. to let an...

Checklist: Using Carrierwave in a Rails project

Posted About 4 years ago by Emanuel.

This checklist should help you to check edge cases that are not part of the default Carrierwave configuration.

Always convert and strip user-provided images to sRGB

Posted About 4 years ago by Michael Leimstädtner.

Debugging image color profiles is hard. You can't trust your eyes in this matter, as the image rendering depends...

Understanding grid sizes of (SVG) icons

Posted Over 4 years ago by Michael Leimstädtner.

A primer on vector graphics For rastered image formats like JPG or PNG, each pixel is basically drawn on a...

A collection of useful design resources for developers

Posted Over 4 years ago by Emanuel.

This collection contains some useful design resources for developers. Many of them were mentioned in the Refactoring UI tutorials.

How to enable Chromedriver logging

Posted Over 4 years ago by Arne Hartherz.

When using Chrome for Selenium tests, the chromedriver binary will be used to control Chrome. To debug problems that stem...