> For the complete documentation index, see [llms.txt](https://docs.alistairtweed.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.alistairtweed.com/rails/minimal-rails/core-modules.md).
# Core Modules
## Active Record
`--skip-active-record [-O]`
## Cable
`--skip-action-cable [-C]`
```ruby
# app/channels/application_cable/channel.rb
module ApplicationCable
class Channel < ActionCable::Channel::Base
end
end
```
```ruby
# app/channels/application_cable/connection.rb
module ApplicationCable
class Connection < ActionCable::Connection::Base
end
end
```
```javascript
// app/javascript/channels/consumer.js
import { createConsumer } from '@rails/actioncable'
export default createConsumer()
```
```javascript
// app/javascript/channels/index.js
const channels = require.context('.', true, /_channel\.js$/)
channels.keys().forEach(channels)
```
```javascript
// app/javascript/packs/application.js
require('channels')
```
```ruby
# config/application.rb
require 'action_cable/engine'
```
```yaml
# config/cable.yml
development:
adapter: async
test:
adapter: test
production:
adapter: redis
url: <%= ENV.fetch("REDIS_URL") { 'redis://localhost:6379/1' } %>
channel_prefix: my_app_production
```
```ruby
# config/environments/production.rb
class Application < Rails::Application
# Mount Action Cable outside main process or domain.
# config.action_cable.mount_path = nil
# config.action_cable.url = 'wss://example.com/cable'
# config.action_cable.allowed_request_origins = [ 'http://example.com', /http:\/\/example.*/ ]
end
```
```ruby
# test/channels/application_cable/connection_test.rb
require 'test_helper'
class ApplicationCable::ConnectionTest < ActionCable::Connection::TestCase
end
```
```ruby
# Gemfile
gem 'redis', '~> 4.0'
```
```javascript
// package.json
{
"dependencies": {
"@rails/actioncable": "^6.0.0"
}
}
```
## Mailer
`--skip-action-mailer [-M]`
{% hint style="info" %}
ActionMailer will add a folder: `test/mailers`
{% endhint %}
```ruby
# app/mailers/application_mailer.rb
class ApplicationMailer < ActionMailer::Base
default from: 'from@example.com'
layout 'mailer'
end
```
```markup
<%= yield %>
```
```
# app/views/layouts/mailer.text.erb
<%= yield %>
```
```ruby
# config/application.rb
require 'action_mailer/railtie'
```
```ruby
# config/environments/development.rb
class Application < Rails::Application
config.action_mailer.raise_delivery_errors = false
config.action_mailer.perform_caching = false
end
```
```ruby
# config/environments/production.rb
class Application < Rails::Application
config.action_mailer.perform_caching = false
# config.action_mailer.raise_delivery_errors = false
end
```
```ruby
# config/environments/test.rb
class Application < Rails::Application
config.action_mailer.perform_caching = false
config.action_mailer.delivery_method = :test
end
```
## Mailbox
`--skip-action-mailbox`
{% hint style="danger" %}
ActionMailbox depends on ActiveStorage
{% endhint %}
```ruby
# config/application.rb
# require 'active_storage/engine'
require 'action_mailbox/engine'
```
## Storage
`--skip-active-storage`
{% hint style="info" %}
ActiveStorage will add two folders: `storage` and `tmp/storage`
{% endhint %}
```javascript
// app/javascript/packs/application.js
require('@rails/activestorage').start()
```
{% hint style="danger" %}
ActionMailbox and ActionText depend on ActiveStorage
{% endhint %}
```ruby
# config/application.rb
require 'active_storage/engine'
# require 'action_mailbox/engine'
# require 'action_text/engine'
```
```ruby
# config/environments/development.rb
class Application < Rails::Application
config.active_storage.service = :local
end
```
```ruby
# config/environments/production.rb
class Application < Rails::Application
config.active_storage.service = :local
end
```
```ruby
# config/environments/test.rb
class Application < Rails::Application
config.active_storage.service = :test
end
```
```yaml
# config/storage.yml
local:
service: Disk
root: <%= Rails.root.join('storage') %>
test:
service: Disk
root: <%= Rails.root.join('tmp/storage') %>
```
```
# .gitignore
/storage/*
!/storage/.keep
```
```ruby
# Gemfile
# gem 'image_processing', '~> 1.2'
```
```javascript
// package.json
{
"dependencies": {
"@rails/activestorage": "^6.0.0"
}
}
```
## Text
`--skip-action-text`
{% hint style="danger" %}
ActionText depends on ActiveStorage
{% endhint %}
```ruby
# config/application.rb
# require 'active_storage/engine'
require 'action_text/engine'
```