How to split a Ruby class into multiple source files - Gem Session
Unfortunately vanilla Ruby modules lack support for many idioms popular in modern Ruby. Most importantly, we have become accustomed to composing our classes with meta-programming macros such as has_many, validates_presence_of or after_save. And modules weren't built with macros in mind.
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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...
Ruby: How to determine the absolute path relative to a file
If you want to get the path of a file relative to another, you can use the expand_path method with either the constant __FILE__ or the method __dir__. Read this card for more information about __FILE__ and __dir__.
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Rbenv: How to remove a gem installed from a Github source
Normally you can list all gems of the current ruby version with gem list, which also includes the gems of you Gemfile. These can be uninstalled with gem uninstall gemname.
List and uninstall a gem installed via Bundler from Github
This d...
How to get information about a gem (via CLI or at runtime from Ruby)
When you need information about a gem (like version(s) or install path(s)), you can use the gem binary from the command line, or the Gem API inside a ruby process at runtime.
gem binary (in a terminal)
You can get some information abou...
How to organize monkey patches in Ruby on Rails projects
As your Rails project grows, you will accumulate a number of small patches. These will usually fix a bug in a gem, or add a method to core classes.
Instead of putting many files into config/initializers, I recommend to group them by gem in ...
How to check if a file is a human readable text file
Ruby's File class has a handy method binary? which checks whether a file is a binary file. This method might be telling the truth most of the time. But sometimes it doesn't, and that's what causes pain. The method is defined as follows:
How to get the hostname of the current machine in Rails or a Ruby script
Use Socket.gethostname. So for a machine whose hostname is "happycat", it will look like this:
>> Socket.gethostname
=> "happycat"
That should work right away for your Rails application. For plain Ruby, you first need to do:
requi...
Ruby: How to load a file with a known encoding
In case Ruby does not detected the expected encoding of a file automatically you can specify the known encoding manually.
Example with File.open
file = File.open('some.bin', encoding: Encoding::ASCII_8BIT)
text = file.read
text.encoding =>...
How to extract a Ruby gem
The rubygems binary gem allows to extract a local gem with gem unpack GEMNAME. For more details see the official documentation.
This was useful for compliance checks, when it ...