Creates named routes for implementing verb-oriented controllers for a singleton resource. A singleton resource is global to its current context. For unnested singleton resources, the resource is global to the current user visiting the application, such as a user’s /account profile. For nested singleton resources, the resource is global to its parent resource, such as a projects resource that has_one :project_manager. The project_manager should be mapped as a singleton resource under projects:

map.resources :projects do |project|
  project.resource :project_manager
end

See map.resources for general conventions. These are the main differences:

• A singular name is given to map.resource. The default controller name is still taken from the plural name.
• To specify a custom plural name, use the :plural option. There is no :singular option.
• No default index route is created for the singleton resource controller.
• When nesting singleton resources, only the singular name is used as the path prefix (example: ‘account/messages/1’)

For example:

map.resource :account

maps these actions in the Accounts controller:

class AccountsController < ActionController::Base
  # GET new_account_url
  def new
    # return an HTML form for describing the new account
  end

  # POST account_url
  def create
    # create an account
  end

  # GET account_url
  def show
    # find and return the account
  end

  # GET edit_account_url
  def edit
    # return an HTML form for editing the account
  end

  # PUT account_url
  def update
    # find and update the account
  end

  # DELETE account_url
  def destroy
    # delete the account
  end
end

Along with the routes themselves, #resource generates named routes for use in controllers and views. map.resource :account produces these named routes and helpers:

Named Route   Helpers
============  =============================================
account       account_url, hash_for_account_url,
              account_path, hash_for_account_path

new_account   new_account_url, hash_for_new_account_url,
              new_account_path, hash_for_new_account_path

edit_account  edit_account_url, hash_for_edit_account_url,
              edit_account_path, hash_for_edit_account_path

Source Code

# File action_controller/resources.rb, line 392
def resource(*entities, &block)
  options = entities.extract_options!
  entities.each { |entity| map_singleton_resource(entity, options.dup, &block) }
end