rails new my_app
cd my_app

gem 'friendly_id', '~> 5.1.0' # Note: You MUST use 5.0.0 or greater for Rails 4.0+
rails generate friendly_id
rails generate scaffold user name:string slug:string:uniq
rake db:migrate

class User < ApplicationRecord
  extend FriendlyId
  friendly_id :name, use: :slugged
end

User.create! name: "wiki"

# Change User.find to User.friendly.find in your controller
User.friendly.find(params[:id])

rails server
GET http://localhost:3000/users/wiki

# If we're adding FriendlyId to an existing app and need
# to generate slugs for existing users, do this from the
# console, runner, or add a Rake task:
User.find_each(&:save)

Finders are no longer overridden by default. If we want to do friendly finds, We must do Model.friendly.find rather than Model.find. We can however restore FriendlyId 4-style finders by using the :finders addon


friendly_id :foo, use: :slugged #we must do MyClass.friendly.find('bar')
#or...
friendly_id :foo, use: [:slugged, :finders] # we can now do MyClass.find('bar')

class Restaurant < ActiveRecord::Base
  extend FriendlyId
  friendly_id :slug_candidates, use: :slugged

  # Try building a slug based on the following fields in
  # increasing order of specificity.
  def slug_candidates
    [
      :name,
      [:name, :city],
      [:name, :street, :city],
      [:name, :street_number, :street, :city]
    ]
  end
end

def normalize_friendly_id(string)
   super[0..40]
end