The Ruby Infinite Hash
How to create an infinitely nestable hash that always defaults to a new hash if a key does not map to a value.
Related cards:
The Ruby Object Model
In Ruby (almost) everything is an Object. While this enables a lot of powerful features, this concept might be confusing for developers who have been programming in more static languages, such as Java or C#. This card should help understanding t...
The JavaScript Object Model: Prototypes and properties
Speaker today is Henning Koch, Head of Development at makandra.
This talk will be in German with English slides.
Introduction
As web developers we work with JavaScript every day, even when our backend code uses anothe...
Security issues with hash conditions in Rails 2 and Rails 3
Find conditions for scopes can be given either as an array (:conditions => ['state = ?', 'draft']) or a hash (:conditions => { 'state' => 'draft' }). The later is nicer to read, but has horrible security implications in some versions of Ru...
How to make changes to a Ruby gem (as a Rails developer)
At makandra, we've built a few gems over the years. Some of these are quite popular: spreewald (> 1M downloads), active_type (> 1M downloads), and geordi (> 200k downloads)
Developing a Ruby gem is different from developing Rails applications, w...
What’s Up With All These Changes in Rails?
Yesterday, there was a blog post entitled “What the Hell is Happening to Rails” that stayed at the number one spot on Hacker News for quite a while. The post and many (but not most) the comments on the post reflect deep-seated concern about the re...
Rubygems: Installing the last version of rubygems that has no rubyforge_project deprecation warning
You can install rubygems 3.0.8 (released on February 18, 2020) to keep all the Gem::Specification#rubyforge_project deprecation warnings away from your development log. With Rubygems >= 3.1 this deprecation warning was introduced. While main...
Iterating over a Ruby Hash while tracking the loop index
You know each_with_index from arrays:
['hello', 'universe'].each_with_index do |value, index|
puts "#{index}: #{value}"
end
# 0: hello
# 1: universe
This also works on hashes. However, mind the required synt...
Ruby constant lookup: The good, the bad and the ugly
In Ruby, classes and modules are called constants. This card explains how Ruby resolves the meaning of a constant.
The good
E. g. in the following example, Array could mean either Foo::Array or simply Array:
class Fo...
Lightning Talk: Coverage based Test Case Prioritization in Ruby on Rails
For my computer science bachelor's thesis I programmed and evaluated a CLI Test Case Prioritization (TCP) tool for makandra. It has been written as a Ruby Gem and was tested and evaluated against one Ruby on Rails project....
Ruby: Using the pry debugger in projects with older Ruby versions
In case you want to use pry with an older version of Ruby, you can try the following configurations.
Ruby 1.8.7
Your pry version must not be greater than 0.9.10.
gem 'pry', '=0.9.10'
gem 'ruby-debug',...