General Ruby conventions

Class names: Use PascalCase for class names:

class ThisIsTheNameOfAClass
end

class Profile
end

Methods and Variables names: Use snake_case for both

## Method:
def example_method
end

## Variable:
awesome_variable = "Hello RoR!"

There are some special methods

## Methods with a `?` suffix will return a boolean.
def admin?
  role == 'admin'
end

user = User.new(role: 'admin')
user.admin? # => true

## Methods with a `!` suffix mean one of two things:
## either the method operates destructively in some fashion,
## or it will raise and exception instead of failing.
user = User.new(email: nil)
user.save   # => false
user.save!  # => ActiveRecord::RecordInvalid: Validation failed: Email can't be blank

Database

Database tables use snake_case. Table names are plural.

Column names in the database use snake_case, but are generally singular.

Example:

+------------------------------+
| profiles                     |
+---------------------+--------+
| id                  | ID     |
| name                | STRING |
| years_of_experience | INT    |
| birthdate           | DATE   |
+---------------------+--------+

Model

Model class names use PascalCase. These are singular, and will map automatically to the plural database table name.

Model attributes and methods use snake_case and match the column names in the database.

Model files go in app/models/#{singular_model_name}.rb.

Example:

# app/models/profile.rb
class Profile < ActiveRecord::Base
  # Methods follow the same conventions as attributes
  def instructor?
    years_of_experience > 2
  end
end

Relations in models

Relations use snake_case and follow the type of relation, so has_one and belongs_to are singular while has_many is plural.

Rails expects foreign keys in the database to have an _id suffix, and will map relations to those keys automatically if the names line up.

Example:

# app/models/article.rb
class Article < ActiveRecord::Base
  # This knows to use the profile_id field in the database
  belongs_to :profile
end

# app/models/profile.rb
class Profile < ActiveRecord::Base
  # This knows to look at the Article class and find the foreign key in that table
  has_many :articles
end

Controllers

Controller class names use PascalCase and have Controller as a suffix. The Controller suffix is always singular. The name of the resource is usually plural.

Controller actions use snake_case and usually match the standard route names Rails defines (index, show, new, create, edit, update, delete).

Controller files go in app/controllers/#{resource_name}_controller.rb.

Example:

# app/controllers/article_controller.rb
ArticleController < ApplicationController
  def index
    # ...
  end
  def show
    # ...
  end
  # etc
end

# app/controllers/profiles_controller.rb
ProfilesController < ApplicationController
  def show
    # ...
  end
  # etc
end

Routes

Route names are snake_case, and usually match the controller. Most of the time routes are plural and use the plural resources.

Singular routes are a special case. These use the singular resource and a singular resource name. However, they still map to a plural controller by default!

Example:

resources :articles
# Users can only see their own profiles, so we'll use `/profile` instead
# of putting an id in the URL.
resource :profile

Views

View file names, by default, match the controller and action that they are tied to.

Views go in app/views/#{resource_name}/#{action_name}.html.erb.

Examples:

app/views/article/index.html.erb
app/views/article/show.html.erb
app/views/profile/show.html.erb

ZarakiLancelot/ruby_and_rails.md

General Ruby conventions

Database

Model

Relations in models

Controllers

Routes

Views

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