Active Model Naming

Creates a model_name method on your object.

To implement, just extend ActiveModel::Naming in your object:

class BookCover
  extend ActiveModel::Naming
end

BookCover.model_name.name   # => "BookCover"
BookCover.model_name.human  # => "Book cover"

BookCover.model_name.i18n_key              # => :book_cover
BookModule::BookCover.model_name.i18n_key  # => :"book_module/book_cover"

Providing the functionality that ActiveModel::Naming provides in your object is required to pass the Active Model Lint test. So either extending the provided method below, or rolling your own is required.

Methods

Class Public methods

param_key(record_or_class)

Returns string to use for params names. It differs for namespaced models regarding whether it's inside isolated engine.

# For isolated engine:
ActiveModel::Naming.param_key(Blog::Post) # => "post"

# For shared engine:
ActiveModel::Naming.param_key(Blog::Post) # => "blog_post"

Source: 

# File activemodel/lib/active_model/naming.rb, line 305
def self.param_key(record_or_class)
  model_name_from_record_or_class(record_or_class).param_key
end

plural(record_or_class)

Returns the plural class name of a record or class.

ActiveModel::Naming.plural(post)             # => "posts"
ActiveModel::Naming.plural(Highrise::Person) # => "highrise_people"

Source: 

# File activemodel/lib/active_model/naming.rb, line 250
def self.plural(record_or_class)
  model_name_from_record_or_class(record_or_class).plural
end

route_key(record_or_class)

Returns string to use while generating route names. It differs for namespaced models regarding whether it's inside isolated engine.

# For isolated engine:
ActiveModel::Naming.route_key(Blog::Post) # => "posts"

# For shared engine:
ActiveModel::Naming.route_key(Blog::Post) # => "blog_posts"

The route key also considers if the noun is uncountable and, in such cases, automatically appends _index.

Source: 

# File activemodel/lib/active_model/naming.rb, line 293
def self.route_key(record_or_class)
  model_name_from_record_or_class(record_or_class).route_key
end

singular(record_or_class)

Returns the singular class name of a record or class.

ActiveModel::Naming.singular(post)             # => "post"
ActiveModel::Naming.singular(Highrise::Person) # => "highrise_person"

Source: 

# File activemodel/lib/active_model/naming.rb, line 258
def self.singular(record_or_class)
  model_name_from_record_or_class(record_or_class).singular
end

singular_route_key(record_or_class)

Returns string to use while generating route names. It differs for namespaced models regarding whether it's inside isolated engine.

# For isolated engine:
ActiveModel::Naming.singular_route_key(Blog::Post) # => "post"

# For shared engine:
ActiveModel::Naming.singular_route_key(Blog::Post) # => "blog_post"

Source: 

# File activemodel/lib/active_model/naming.rb, line 278
def self.singular_route_key(record_or_class)
  model_name_from_record_or_class(record_or_class).singular_route_key
end

uncountable?(record_or_class)

Identifies whether the class name of a record or class is uncountable.

ActiveModel::Naming.uncountable?(Sheep) # => true
ActiveModel::Naming.uncountable?(Post)  # => false

Source: 

# File activemodel/lib/active_model/naming.rb, line 266
def self.uncountable?(record_or_class)
  plural(record_or_class) == singular(record_or_class)
end

Instance Public methods

model_name()

Returns an ActiveModel::Name object for module. It can be used to retrieve all kinds of naming-related information (See ActiveModel::Name for more information).

class Person
  extend ActiveModel::Naming
end

Person.model_name.name     # => "Person"
Person.model_name.class    # => ActiveModel::Name
Person.model_name.singular # => "person"
Person.model_name.plural   # => "people"

Source: 

# File activemodel/lib/active_model/naming.rb, line 237
def model_name
  @_model_name ||= begin
    namespace = parents.detect do |n|
      n.respond_to?(:use_relative_model_naming?) && n.use_relative_model_naming?
    end
    ActiveModel::Name.new(self, namespace)
  end
end