Rails 5's ApplicationRecord is the place to put generic model logic

This cards describes an example with a Github Client on how to keep your Rails application more maintainable by extracting domain independent code from the app/models folder to the lib/ folder. The approach is applicable to arbitrary scenarios...

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...

When you want to find out the data type of an attribute, you can just use ActiveRecord's columns_hash method.

It returns a hash of column objects that include a type attribute (and more database-related information).

Example:

Contract.c...

In a nutshell:

If you require your Rails models manually, pay attention to the path you use. Unless you have to, don't do it at all.

Background

Consider these classes:

# app/models/user.rb

class User < ActiveRecord::Base

...

Specify these gem versions in your Gemfile:

gem 'cucumber', '~> 1.3.0'
gem 'cucumber-rails', '= 0.3.2' # max version for Rails 2
gem 'capybara', '< 2' # capybara 2+ requires Rails 3
gem 'mime-types', '< 2' # dependeny of capybara

...

Note that this seems to affect only recent Rails 2 versions.

You will not encounter this until you are writing to the cookie more than once, but when doing so, integration tests (Cucumber) may break for you with this error:

You have a nil ob...

Instantiating ActiveRecord objects comes expensive. To speed up things, you can choose a more direct way to talk to your database: the [ActiveRecord::ConnectionAdapters::DatabaseStatements](http://api.rubyonrails.org/classes/ActiveRecord/Connect...

In general, you should not put a block element inside an inline element. So don't do this:

<span>
  <div>text</div>
</span>

The browser will think you wrote invalid HTML by accident, and will sometimes reorder elements silently.
...

In this example we assume that not only the storage gem changes but also the file structure on disc.

A general approach

Part A: Create a commit which includes a script that allows you to copy the existing file to the new file structure.
...