Rails: friendly_id slug relationship

Question

I want to create a slug for my model which depends on a column of a related model. Is that possible?

Here is what I've thought:

# Example::User class
extend FriendlyId
friendly_id user.username, use: :slugged
belongs_to :user, class_name: "::User"

I get the following error:

NoMethodError: undefined method `username' for nil:NilClass

Edit: How records are created.

I have a User and Example::User model.
When running:

User.create(email: "demo@example.com", name: "demo", password: "12345678").encrypted_password

a Example::User record gets automatically created:

# User class
before_action :create_example_user

has_one :example_user, class_name: "Example::User"

def create_example_user
    Example::User.create(user_id: self.id)
end

kobaltz · Accepted Answer · 2017-03-26T08:26:42.347

1

Try something like this

extend FriendlyID
friendly_id user_username, use: :slugged
belongs_to :user

def user_username
  user.username
end

Edit:

Because your example user is trying to reference the user prior to the user being saved, it is causing the error.

Changing

def create_example_user
    Example::User.create(user_id: self.id)
end

to

def create_example_user
    self.build_example_user
end

may fix the problem

edited Mar 26 '17 at 08:26

answered Mar 26 '17 at 07:31

kobaltz

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Can you post the relevant code that is creating the user and this association? – kobaltz Mar 26 '17 at 07:46
in your `before_action` callback, try changing `Example::User.create(user_id: self.id)` to `self.example_user.create` – kobaltz Mar 26 '17 at 08:11
Hmm.. I get `NoMethodError: undefined method `create' for nil:NilClass`. Dunno why the relation is not working... – heroxav Mar 26 '17 at 08:22
My bad, the example user doesn't exist yet. Try `self.build_example_user` – kobaltz Mar 26 '17 at 08:26
that gives me: `SystemStackError: stack level too deep` – heroxav Mar 26 '17 at 08:34
is that maybe creating new `User` and `Example::User` records? – heroxav Mar 26 '17 at 08:38

Rails: friendly_id slug relationship

1 Answers1