tilInteresting Rails Conventions

As a noob in programming in Ruby on Rails, I feel like there’s a lot to learn. Unfortunately Intellisense doesn’t work great leading to harder discoverability. Convention over configuration is great, but only if you already know that convention. Here’s some miscellaneous things that I found interesting while reading the Ruby on Rails guides (for v7.1.2).

Disclaimer: I’m still very new to this, so if anything here is wrong please let me know!

Notes:

• In regex, use \A and \z to indicate the start and end of the string. ¹

• has_many :books, dependent: :destroy ²

• Use has_and_belongs_to_many to build an implicit join table easily, otherwise has_many :through

• Symbol vs String: Use Symbol when the identity of it matters, use String when contents matter

• -> { method } or ->(args) { method(args)} is a lambda

• Metaprogramming makes things confusing. As a beginner, try not to touch it if possible (and to keep code readable).

• ActiveJob is really cool

• You can use <%= method %> erb-style interpolation in YAML files, somehow. I should figure out how.

• An ActiveStorage “file” is called an attachment

• You should periodically purge unattached uploads ³

Full text:

class Author < ApplicationRecord
  has_many :books, dependent: :destroy
end

class Book < ApplicationRecord
  belongs_to :author
end

namespace :active_storage do
  desc "Purges unattached Active Storage blobs. Run regularly."
  task purge_unattached: :environment do
    ActiveStorage::Blob.unattached.where(created_at: ..2.days.ago).find_each(&:purge_later)
  end
end

The query generated by ActiveStorage::Blob.unattached can be slow and potentially disruptive on applications with larger databases.