IMPORTANT: If you are upgrading to Mongoid Slug 1.0.0 please migrate in accordance with the instructions in https://github.com/digitalplaywright/mongoid-slug/wiki/How-to-upgrade-to-1.0.0. Mongoid Slug 1.0.0 stores the slugs in a single field _slugs of array type, and all previous slugs must be migrated.

Mongoid Slug

Mongoid Slug generates a URL slug or permalink based on one or more fields in a Mongoid model. It sits idly on top of [stringex] 1, supporting non-Latin characters.

Installation

Add to your Gemfile:

gem 'mongoid_slug'

Usage

Set up a slug:

class Book
  include Mongoid::Document
  include Mongoid::Slug

  field :title
  slug :title
end

Find a document by its slug:

# GET /books/a-thousand-plateaus
book = Book.find params[:book_id]

Mongoid Slug will attempt to determine whether you want to find using the slugs field or the _id field by inspecting the supplied parameters.

• If your document uses BSON::ObjectId identifiers, and all arguments passed to find are String and look like valid BSON::ObjectId, then Mongoid Slug will perform a find based on _id.
• If your document uses any other type of identifiers, and all arguments passed to find are of the same type, then Mongoid Slug will perform a find based on _id.
• Otherwise, if all arguments passed to find are of the type String, then Mongoid Slug will perform a find based on slugs.

To override this behaviour you may supply a hash of options as the final argument to find with the key force_slugs set to true or false as required. For example:

Book.fields['_id'].type
=> String
book = Book.find 'a-thousand-plateaus' # Finds by _id
=> ...
book = Book.find 'a-thousand-plateaus', { force_slugs: true } # Finds by slugs
=> ...

[Read here] 4 for all available options.

Custom Slug Generation

By default Mongoid Slug generates slugs with stringex. If this is not desired you can define your own slug generator like this:

class Caption
  include Mongoid::Document
  include Mongoid::Slug

  #create a block that takes the current object as an argument
  #and returns the slug.
  slug do |cur_object|
    cur_object.slug_builder.to_url
  end
end

Scoping

To scope a slug by a reference association, pass :scope:

class Company
  include Mongoid::Document
  
  references_many :employees
end

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

In this example, if you create an employee without associating it with any company, the scope will fall back to the root employees collection.

Currently, if you have an irregular association name, you must specify the :inverse_of option on the other side of the assocation.

Embedded objects are automatically scoped by their parent.

The value of :scope can alternatively be a field within the model itself:

class Employee
  include Mongoid::Document
  include Mongoid::Slug
  
  field :name
  field :company_id
  
  slug  :name, :scope => :company_id
end

History

To specify that the history of a document should be kept track of, pass :history with a value of true.

class Page
  include Mongoid::Document
  include Mongoid::Slug
  
  field :title
  
  slug :title, history: true
end

The document will then be returned for any of the saved slugs:

page = Page.new title: "Home"
page.save
page.update_attributes title: "Welcome"

Page.find("welcome") == Page.find("home") #=> true

Reserved Slugs

Pass words you do not want to be slugged using the reserve option:

class Friend
  include Mongoid::Document

  field :name
  slug :name, reserve: ['admin', 'root']
end

friend = Friend.create name: 'admin'
Friend.find('admin') # => nil
friend.slug # => 'admin-1'