Public Id

Description

Simplifies the generation and use of unique, random identifiers for ActiveRecord models.

We generate a string of random (using SecureRandom) alphanumeric characters (a-z, A-Z, 0-9) along with an optional prefix that defaults to the first 3 characters of the model name. The random string has a default length of 12, providing 62 ^ 12 possible strings.

On assignment to the model, if duplicate ID is detected in the database, a new random identifier is generated.

Installation

Add to Gemfile / etc

gem 'public_id'

Usage

Add an additional identifier column. I called it "ident", but call it whatever you want.

# Identifier column MUST be a string
rails generate migration add_ident_to_users ident:string

Tell your activerecord object that ident is your new public identifier.

class User < ActiveRecord::Base
  has_public_id :ident, prefix: 'user'
  # Automatically defines to_param as :ident
end
User.new.ident
# => "user-ECNrdIzvCBh8"

Now change your controllers to lookup the public ID instead of your database ID

class UserController < ApplicationController
  def show
    User.find_by_public_id(params[:id])
    # Or User.find_by_ident(params[:id])
    # Nothing fancy here
  end
end

There's a few other convenience methods that you may find useful.

• Initialize ID's for existing records, useful in a migration.

    def change
      add_column :users, :ident, :string
      User.initialize_public_ids!
    end
  

  • Get a new random ID for your own nefarious purposes:

User.new_public_id

Configuration

By default, ID's have 2 components. A 3 character lowercase prefix of their originating class name and a suffix of a 14 character random, unique, base64 url safe string. The suffix and prefix are joined by a dash.

You can skip the prefix alltogether:

  has_public_id column_name, length: 10, prefix: false

or set it directly:

  has_public_id other_column_name, length: 15, prefix: 'user_'

The "length" option refers to the length argument passed to SecureRandom. The actual length of the random base64 string will be about 4/3's this length. The defaults to 10, for a 14 character base64 string.

Contribute

• Fork this project
• Add tests
• Submit a pull request

This project rocks and uses MIT-LICENSE.