> For the complete documentation index, see [llms.txt](https://doorkeeper.gitbook.io/guides/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://doorkeeper.gitbook.io/guides/ruby-on-rails/polymorphic-resource-owner.md).

# Polymorphic Resource Owner

Enables polymorphic Resource Owner feature for Doorkeeper Access Tokens & Grants. By default Doorkeeper set only `resource_owner_id` without knowing model name of the Resource Owner.

Feature available only starting from Doorkeeper 5.4.

### How to use it

Enable configuration option:

{% tabs %}
{% tab title="config/initializers/doorkeeper.rb" %}

```ruby
Doorkeeper.configure do
  orm :active_record

  use_polymorphic_resource_owner
end
```

{% endtab %}
{% endtabs %}

Generate migration to add polymorphic columns to tables:

```bash
$ bundle exec rails g doorkeeper:enable_polymorphic_resource_owner
```

If you previously set foreign key for `:resource_owner_id` column - you need to drop it as now it would be a polymorphic association. You can drop FK in the migration generated above.

Run the migration:

```bash
$ bundle exec rails db:migrate
```

Use the feature!

Now you can access resource owner by `doorkeeper_token.resource_owner` association.

:warning: :warning: **\[ATTENTION]**: If you enabled this option on existing project - you need to manually set polymorphic type column with the class of the Resource Owner. Otherwise your existing users/clients could face issues and spam you logs with errors.

:warning: :warning: **\[ATTENTION]**: Also this feature could be a breaking change for those users that patched Doorkeeper internals, specially models. You need to fix your patches to user `resource_owner` instance instead of it's ID (like it was before).

## Known projects affected

* GitLab (<https://gitlab.com/gitlab-org/gitlab-foss/blob/master/config/initializers/doorkeeper.rb#L129>)
* Doorkeeper ORM extensions

Original PR: <https://github.com/doorkeeper-gem/doorkeeper/pull/1355>