Mongoid Slug

Mongoid Slug generates a URL slug or permalink based on one or more fields in a Mongoid model. It sits on top of stringex and works with non-Latin characters.

Quick Start

First, add mongoid_slug to your Gemfile:

gem 'mongoid_slug', :require => 'mongoid/slug'

Say you have a book that embeds many authors. You can set up slugs for both resources like this:

class Book
  include Mongoid::Document
  include Mongoid::Slug
  field :title
  slug  :title
  embeds_many :authors
end

class Author
  include Mongoid::Document
  include Mongoid::Slug
  field :first_name
  field :last_name
  slug  :first_name, :last_name
  embedded_in :book, :inverse_of => :authors
end

In your controller, you can use the find_by_slug helper:

def find_book
  Book.find_by_slug(params[:book_id])
end

def find_author
  @book.authors.find_by_slug(params[:id])
end

To demo some more functionality in the console:

>> book = Book.create(:title => "A Thousand Plateaus")
>> book.to_param
"a-thousand-plateaus"
>> book.title = "Anti Oedipus"
>> book.save
>> book.to_param
"anti-oedipus"
>> author = book.authors.create(:first_name => "Gilles", :last_name => "Deleuze")
>> author.to_param
=> "gilles-deleuze"
>> author.update_attributes(:first_name => "Félix", :last_name => "Guattari")
>> author.to_param
=> "felix-guattari"

Scoping by Associations

Objects that are embedded in a parent document automatically have their slug uniqueness scoped to the parent. If you wish to scope by a reference association, you can pass a :scope option to the slug class method:

class Company
  include Mongoid::Document
  field :name
  references_many :employees
end

class Employee
  include Mongoid::Document
  include Mongoid::Slug
  field :first_name
  field :last_name
  slug  :first_name, :last_name, :scope => :company
  referenced_in :company
end

In this example, if you create an employee without associating it with any company, the slug scope will fall back to the root employees collection. Currently if you have an irregular association name, for instance:

references_many :employees, :class_name => 'Person', :foreign_key => :company_id

you must specify the :inverse_of option on the other side of the assocation.

Indexing

You may optionally pass an :index option to generate an index on the slug in top-level objects.

class Book
  field :title
  slug  :title, :index => true
end

Indexes on non-scoped slugs will be unique.