---
title: "Role scopes with gem Rolify"
author: "Yaroslav Shmarov"
date: "2021-06-07"
canonical_url: "https://blog.superails.com/rolify-scopes"
markdown_url: "https://blog.superails.com/rolify-scopes.md"
description: "The magic of Rolify is not in just assigning user roles, but in assigning user roles to resources."
tags: ["ruby","rails","ruby-on-rails","rolify"]
license: "GNU AGPL v3. Credit Yaroslav Shmarov and link the canonical URL."
video_url: "https://www.youtube.com/watch?v=URDKxGn0pxo"
---

# Role scopes with gem Rolify

The magic of Rolify is not in just **assigning user roles**, but in assigning user roles to resources. 

Meaning, 2 different posts can easily have different **admins** and **moderators**.

But Rolify has no default scopes to see all user with a role for a post, or all posts that a user has a role for.

Here are some example relationship scopes that you can add to your models and fix the "problem":

### Scoping

user.rb
```ruby
has_many :posts, through: :roles, source: :resource, source_type: :Post
has_many :moderated_posts, -> { where(roles: {name: :moderator}) }, through: :roles, source: :resource, source_type: :Post
```
let's you do
```ruby
@user.posts 
# => [ all the posts where the @user has a role ]
@user.moderated_posts
# => [ all the posts where the @user has a moderator ]
```
post.rb
```ruby
has_many :users, through: :roles, class_name: 'User', source: :users
has_many :moderators, -> { where(:roles => {name: :moderator}) }, through: :roles, class_name: 'User', source: :users
```
let's you do
```ruby
@post.users
# => [ all the users that have a role in this post ]
@post.moderators
# => [ all the users that have a moderator role in this post ]
```