Rails gem "friendly_id": How to get a live preview of the slug, before its object is created

Question

Using the Rails gem "friendly_id", is it possible to get a "live preview" of the slug to be created? Before the object is saved, that is (and to be returned while typing using an ajax request)?

If so, how?

Answer 1

FriendyId author here.

FriendlyId internally uses the private set_slug to do this. This method is invoked via a before_validation callback. If for some reason you do not wish to call valid?, you can invoke the set_slug method via send, or define a method in your model which invokes it:

instance = ModelClass.new
instance.send(:set_slug)

# or
class ModelClass < ActiveRecord::Base
  friendly_id :name, use: :slugged

  def generate_slug_preview
    set_slug
  end
end 

However, note that bypassing or ignoring validations is often a bad idea. For example, if your model included a validation on the name field, and then you used that field as the basis of the slug, then you are previewing a slug that will never actually be generated.