Authorization settings using pundit gem rails - ruby-on-rails

Question

I'm new at rails so bear with me pls. My problem is so specific. I'm creating a User blog, where they could put any posts. So Users has a blogs, and blogs has posts. So when user create a blog, all posts in his blog should be written by him. Other users can't write not on their blogs.
post_controller.rb
class PostsController < ApplicationController
before_action :authenticate_user!
before_action :authorize_user!, only: [:edit, :update, :destroy]
expose :blog
expose :post
def show
end
def new
end
def edit
end
def create
post.user = current_user
post.save
respond_with post, location: user_blog_path(post.blog.user, post.blog)
end
def update
post.update(post_params)
respond_with post, location: user_blog_path(post.blog.user, post.blog)
end
def destroy
post.destroy
respond_with post, location: user_blog_path(post.blog.user, post.blog)
end
private
def authorize_user!
authorize(post, :authorized?)
end
def post_params
params.require(:post).permit(:title, :content, :user_id, :blog_id)
end
end
Here i'm using pundit to authorize user, when they update or destroy posts (users can update or destroy only their own posts) and it works perfectly.
views/posts/new
.row
.columns
h2 = title("New post")
.row
.medium-5.columns
= simple_form_for post do |f|
= f.error_notification
.form-inputs
= f.input :title
= f.input :content
= f.hidden_field :blog_id, value: blog.id
.form-actions
= f.button :submit
Here i'm using the hidden form to set the blog_id which I take from params. Http link looks like http://localhost:3000/posts/new?blog_id=6. The problem is that each user can copy this link to create the post( and they are not the blog owners).
post_policy.rb
class PostPolicy < ApplicationPolicy
def authorized?
record.user == user
end
end
How should I check the blog's owner before post creating? Maybe I have a wrong way to create posts like this(using hidden form).
Link to create new post
= link_to 'New Post', new_post_path(blog_id: blog.id)

Answer 1

I hope, it will work for you
application_controller.rb
class ApplicationController
include Pundit
after_action :verify_authorized, except: :index
after_action :verify_policy_scoped, only: :index
before_action :authenticate_admin_user!
helper_method :current_user
def pundit_user
current_admin_user
end
def current_user
#current_user ||= User.find(current_admin_user.id)
end
end
posts_controller.rb
class PostsController < ApplicationController
before_action :set_blog
def new
authorize(Post)
end
def edit
#post = #blog.posts.find(params[:id])
authorize(#post)
end
def index
#posts = policy_scope(#blog.posts)
end
private
def set_blog
#blog = current_user.blogs.find(params[:blog_id])
end
end
post_policy.rb
class PostPolicy < ApplicationPolicy
def show?
true
end
def index?
true
end
def new?
create?
end
def create?
true
end
def edit?
update?
end
def update?
scope_include_object?
end
def destroy?
scope_include_object?
end
class Scope < Scope
def resolve
scope.joins(:blog).where(blogs: { admin_user_id: user.id })
end
end
def scope_include_object?
scope.where(id: record.id).exists?
end
end
routes.rb
Rails.application.routes.draw do
devise_for :admin_users
resources :blogs do
resources :posts
end
end