Undefined method songs - ruby-on-rails

I am trying to submit songs to a particular event, and the only thing that is stopping me is an error message. I have gotten this to work when a user has events, but not when a event has songs. Here is what my code looks like:
Event model:
class Event < ApplicationRecord
belongs_to :user
has_many :songs, dependent: :destroy
end
Song model:
class Song < ApplicationRecord
belongs_to :event
validates :artist, presence: true
validates :title, presence: true
end
Events controller
class EventsController < ApplicationController
def show
#event = Event.find(params[:id])
#songs = #event.songs.paginate(page: params[:page])
end
def create
#event = current_user.events.build(event_params)
if #event.save
redirect_to root_url
else
redirect_to root_url
end
end
def destroy
end
private
def event_params
params.require(:event).permit(:name, :code)
end
end
Song controller
class SongsController < ApplicationController
def create
#song = current_event.songs.build(song_params)
if #song.save
flash[:success] = "Song Created"
redirect_to root_url
else
render 'users/show'
end
end
def destroy
end
private
def song_params
params.require(:song).permit(:artist, :title)
end
end
sessions_helper.rb
module SessionsHelper
# Logs in the given user.
def log_in(user)
session[:user_id] = user.id
end
# Returns the current logged-in user (if any).
def current_user
#current_user ||= User.find_by(id: session[:user_id])
end
def current_event
#current_event ||= Event.find_by(id: session[:event_id])
end
# Returns true if the user is logged in, false otherwise.
def logged_in?
!current_user.nil?
end
def log_out
session.delete(:user_id)
#current_user = nil
end
end
Any help on this would be fantastic!

Your current_event method is looking for a session to get the event_id
def current_event
#current_event ||= Event.find_by(id: session[:event_id])
end
But you are not setting a session for this.
You are on the user session:
# Logs in the given user.
def log_in(user)
session[:user_id] = user.id
end
# Returns the current logged-in user (if any).
def current_user
#current_user ||= User.find_by(id: session[:user_id])
end
The result being that current_event is likely not returning an event object (its nil) and therefore .songs is not a valid method to call on it.
So you need to either set a session with event_id or come at it a different way (not using sessions).
Hope it helps

Related

Can't delete using pundit as user.admin or record.user. How can I get them to delete?

I'm using the Pundit gem for the user authorizations in my Rails project. The Edit function works as I expected, just user admin and whoever created the review is able to update it. However, I can't delete them with the pundit set up.
Here's my Reviews Controller:
class ReviewsController < ApplicationController
before_action :set_review, only: [:show, :edit, :update, :destroy]
def index
#reviews = Review.all
end
def new
#review = Review.new
end
def create
#review = Review.new(review_params)
#review.user_id = current_user.id
if #review.save
redirect_to review_path(#review), :alert => "Awesome! Here's your small review!"
else
error_messages(#review)
render 'new'
end
end
def show
end
def edit
authorize #review
end
def update
if #review.update(review_params)
redirect_to review_path(#review), :alert => "That's a good update!"
else
error_messages(#review)
render 'edit'
end
end
def destroy
authorize #review
#review.destroy
redirect_to reviews_path, :alert => "We'll miss that review."
end
private
def set_review
#review = Review.find_by(id: params[:id])
end
def review_params
params.require(:review).permit(:title, :content)
end
end
The Application Policy looks like this:
class ApplicationPolicy
attr_reader :user, :record
def initialize(user, record)
#user = user
#record = record
end
def index?
false
end
def show?
false
end
def create?
false
end
def create?
new?
end
def update?
false
end
def edit?
update?
end
def destroy?
destroy?
end
class Scope
attr_reader :user, :scope
def initialize(user, scope)
#user = user
#scope = scope
end
def resolve
scope.all
end
end
end
And here's my customized Review Policy file:
class ReviewPolicy < ApplicationPolicy
def edit?
user.admin? || record.user == user
end
def destroy?
user.admin? || record.user == user
end
end
In case you're wondering, I created the user_not_authorized helper method. My Application Controller looks like this.
class ApplicationController < ActionController::Base
include Pundit
rescue_from Pundit::NotAuthorizedError, with: :user_not_authorized
protect_from_forgery with: :exception
helper_method :current_user
add_flash_types :info, :error, :warning
def logged_in?
!!current_user
end
def current_user
#current_user ||= User.find_by(id: session[:user_id])
end
def error_messages(obj)
obj.errors.messages.each do |k,v|
flash[:alert] = "#{k.to_s} #{v.first.to_s}"
end
end
private
def user_not_authorized
flash[:alert] = "Ooops sorry. You don't have access to this."
redirect_to (request.referrer || root_path)
end
end
Hope my message is clear enough and would appreciate any help. Remember, '''user.admin? || record.user == user''' works for editing but the user admins and the review creators can't delete the reviews when applying the same methods.
Please let me know if any question.

Error getting user's name and email from the associated model in Ruby on Rails

I am creating a webiste where people can debate with each other. It has 4 main models - post, for_the_motion, against_the_motion, and user( added in the respective order). I ran a migration and made a association between for model and against model.
For each view in "for" model I want to show which user added that particular motion. But I am getting an error
undefined method `image_url' for nil:NilClass
Stuck from long time on this. This is how the models look
user.rb
class User < ApplicationRecord
has_many :posts
has_many :fors
has_many :againsts
class << self
def from_omniauth(auth_hash)
user = find_or_create_by(uid: auth_hash['uid'], provider: auth_hash['provider'])
user.name = auth_hash['info']['name']
user.image_url = auth_hash['info']['image']
user.url = auth_hash['info']['urls'][user.provider.capitalize]
user.save!
user
end
end
end
for.rb
class For < ApplicationRecord
belongs_to :post, optional: true
belongs_to :user,optional: true
end
post.rb
class Post < ApplicationRecord
has_many :fors, dependent: :destroy
has_many :againsts, dependent: :destroy
belongs_to :user, optional: true
end
against.rb
class Against < ApplicationRecord
belongs_to :post, optional: true
belongs_to :user, optional:true
end
CONTROLLERS
posts_controller.rb
class PostsController < ApplicationController
def index
#posts = Post.all
end
def land
end
def show
#post = Post.find(params[:id])
end
def new
#post = Post.new
end
def create
#post = Post.new(post_params)
#post.user = current_user
if #post.save
redirect_to #post
else
render 'new'
end
end
private
def post_params
params.require(:post).permit(:title)
end
end
fors_controller.rb
class ForsController < ApplicationController
def create
#post = Post.find(params[:post_id])
#for = #post.fors.create(fors_params)
#for.user = current_user
redirect_to post_path(#post)
end
private
def fors_params
params.require(:for).permit(:content)
end
end
sessions_controller.rb
class SessionsController < ApplicationController
def create
begin
#user = User.from_omniauth(request.env['omniauth.auth'])
session[:user_id] = #user.id
# flash[:success] = "Welcome, #{#user.name}!"
rescue
# flash[:warning] = "There was an error while trying to authenticate you..."
end
redirect_to root_path
def destroy
if current_user
session.delete(:user_id)
# flash[:success] = 'See you!'
end
redirect_to root_path
end
end
end
This is where I am getting the error
<h1><%=#post.title%></h1>
<div class="fort">
<h3>For the motion</h3>
<%#post.fors.each do |f|%>
<p><%=f.content%></p>
<p><%=f.user.image_url%></p>/*This is where errors arise*/
<%end%>
<%= render "fors/form"%>
</div>
<div class="against">
<h3>Against the motion</h3>
<%#post.againsts.each do |f|%>
<p><%=f.content%></p>
<p><%= #post.user.name%></p>
<%end%>
<%= render "againsts/form"%>
</div>
Here is the github link for any other required information
https://github.com/sarfrazbaig/DebatingSociety2
Seems like you missed saving the .user on fors_controller.rb:
class ForsController < ApplicationController
def create
#post = Post.find(params[:post_id])
#for = #post.fors.create(fors_params)
# .create above already will save a new For record in DB
# therefore your #for.user assignation will be only assigned in memory, but not yet in DB
#for.user = current_user
# you'll need to save it again afterwards:
#for.save
redirect_to post_path(#post)
end
# ...
end
Suggestion:
use .new instead of .create to not-yet-save into the DB, and only call save when everything that you need to assign is already assigned.
class ForsController < ApplicationController
def create
#post = Post.find(params[:post_id])
#for = #post.fors.new(fors_params)
#for.user = current_user
#for.save
redirect_to post_path(#post)
end
# ...
end
Take note that you would still encounter that error even if you already updated your code with the above; this is because currently your For records in the DB all are missing the .user value. You'll have to manually assign and save the .user accordingly for each For record, and probably best that you'd write a...
class For < ApplicationRecord
validates :user, presence: true
end
... validation so that this error will be prevented in the future.
One of the #post.fors is lacking a user, which is permitted by the belongs_to :user, optional: true in your For model.
You can restrict your query to showing only fors that have an associated user:
#post.fors.joins(:users) or you can use the safe navigation operator to return nil when attempting to read the image_url for a non-existent user - f.user&.image_url

How to retrieve nested model data from another model? : undefined method error

So the basis of my code so far is:
a customer has_one calendar
a calendar belongs_to a customer
a calendar has_many events
an event belongs_to a calendar
I am trying to, when creating a new event, specify the customer and calendar it belongs to but it throws error "undefined method `Calendar'":
class EventsController < ApplicationController
def new
#event = Event.new
#currentcalendar = current_customer.calendar # this is where it is failing
end
def create
if #event = #currentcalendar.build.event(event_params)
redirect_to '/main'
else
redirect_to '/compose'
end
end
private
def event_params
params.require(:event).permit(:calendar_id, :name, :starts_at, :ends_at)
end
end
this is my current_customer method within application_controller:
def current_customer
if (customer_id = session[:customer_id])
#current_customer ||= Customer.find_by(id: customer_id)
elsif (customer_id = cookies.signed[:customer_id])
customer = Customer.find_by(id: customer_id)
if customer && customer.authenticated?(cookies[:remember_token])
session[:customer_id] = customer.id #log in
#current_customer = customer
end
end
end
Here are the related controller files. Customer:
class CustomersController < ApplicationController
def new
#customer = Customer.new
#businesses = Business.all
#calendar = Calendar.new
end
def create
#customer = Customer.create(customer_params)
#calendar = #customer.build_calendar
#customer.save!
session[:customer_id] = #customer.id
redirect_to '/'
rescue ActiveRecord::RecordInvalid => ex
render action: 'new', alert: ex.message
end
private
def customer_params
params.require(:customer).permit(:first_name, :last_name, :business_no, :email, :password, :business_id)
end
Calendar:
class CalendarsController < ApplicationController
def new
#calendar = Calendar.new(calendar_params)
end
def create
#calendar = Calendar.new(calendar_params)
end
private
def calendar_params
params.require(:customer_id)
end
end
I'm very new to Ruby/ Rails and so can't figure this out by myself. Is this problem occurring because I have wrongly created my calendar? I wanted it to be created when its user is created, which works, but I just don't know how to get to the calendar and user within the events controller.
Thanks for your help!
EDIT: these are the model classes.
customer:
class Customer < ActiveRecord::Base
belongs_to :business
has_one :calendar
has_secure_password
attr_accessor :remember_token
#remembers a user in the database for use in persistent sessions
def remember
self.remember_token = Customer.new_token
update_attribute(:remember_digest, Customer.digest(remember_token))
end
def Customer.digest(string)
cost = ActiveModel::SecurePassword.min_cost ? BCrypt::Engine::MIN_COST :
BCrypt::Engine.cost
BCrypt::Password.create(string, cost: cost)
end
def forget
update_attribute(:remember_digest, nil)
end
def Customer.new_token
SecureRandom.urlsafe_base64
end
#returns true if the given token matches the digest
def authenticated?(remember_token)
BCrypt::Password.new(remember_digest).is_password?(remember_token)
end
end
calendar:
class Calendar < ActiveRecord::Base
belongs_to :customer
has_many :events
end
event:
class Event < ActiveRecord::Base
belongs_to :calendar
end
Your current_customer can be nil at times. To avoid this you can add a before_filter callback that checks if there is a customer that is logged in or not.
In your application_controller create a method called customer_found?
def customer_found?
current_customer.present?
end
Change your events controller to
class EventsController < ApplicationController
before_filter :customer_found?
before_filter :prepare_calendar, only: [:new, :create]
def new
#event = Event.new
end
def create
if #event = #current_calendar.build.event(event_params)
redirect_to '/main'
else
redirect_to '/compose'
end
end
private
def prepare_calendar
#current_calendar = current_customer.calendar
end
def event_params
params.require(:event).permit(:calendar_id, :name, :starts_at, :ends_at)
end
end
Since you did not assign your #current_calendar in your create method then you are gonna get undefined method build for nil class. You need to initialize the variable since it can not get it from the new method. Each action has its own independent variables so make sure to prepare all necessary variables before using them.

Pundit - Policies are not recognised

I am implementing pundit and wish to restrict the user#edit and user#update actions to only the current_user
def edit
#user = current_user
authorize(#user)
end
def update
#user = current_user
authorise(#user)
if #user.update_attributes(user_params)
flash[:success] = "Profile updated"
redirect_to edit_user_path
else
render 'edit'
end
end
The following is my attempted policy which (a) does not work and (b) is illogical.
class UserPolicy
attr_reader :user, :user
def initialise(user, user)
#user = user
end
def update?
true
end
alias_method :edit?, :update?
end
I have now updated my UserPolicy as per below. I have set the actions to false for testing as everything was being authorised:
class UserPolicy < ApplicationPolicy
def new?
create?
end
def create?
false
end
def edit?
update?
end
def update?
false
#user.id == record.id
end
end
However my policies are not recognised. Upon further reading I added the following to my ApplicationController:
after_filter :verify_authorized, except: :index
after_filter :verify_policy_scoped, only: :index
When I now navigate to my user#edit action I receive:
Pundit::AuthorizationNotPerformedError
First, make sure you have...
your-app/app/controllers/application_controller.rb
class ApplicationController < ActionController::Base
include Pundit
end
your-app/app/policies/application_policy.rb with default permissions for common actions.
class ApplicationPolicy
attr_reader :user, :record
def initialize(user, record)
#user = user
#record = record
end
def index?
false
end
def show?
scope.where(:id => record.id).exists?
end
def create?
false
end
def new?
create?
end
def update?
false
end
def edit?
update?
end
def destroy?
false
end
def scope
Pundit.policy_scope!(user, record.class)
end
class Scope
attr_reader :user, :scope
def initialize(user, scope)
#user = user
#scope = scope
end
def resolve
scope
end
end
Then, in your UserPolicy
your-app/app/policies/section_policy.rb
class UserPolicy < ApplicationPolicy
def edit?
user.id == record.id
end
def update?
edit?
end
end
So, by default, user will be your current user and record will be the #user defined on edit and update actions.
You don't need to call authorize method explicitly. Pundit knows what to do with your #user attribute. So, your controller should be:
def edit
user
end
def update
if user.update_attributes(user_params)
flash[:success] = "Profile updated"
redirect_to edit_user_path
else
render 'edit'
end
end
private
def user
#user ||= User.find(params[:id])
end
you must know if you don't have a current_user method, yo will need to define a pundit_user in your application controller.

In rails, defining Pundit scope subclass to display different sets of posts depending on the type of user

Hello, I'm new to ruby on rails, and currently working on an exercise where I have 3 types of users ( Admin, moderator and member). I'm using the Pundit gem with the Devise Gem.
I was asked to define Pundit scope classes to make Posts accessible according to the role of the user.
Admin and moderator can see all posts. Signed in user can see his posts only. A guest can't see the posts.
Here's the PostsController:
class PostsController < ApplicationController
def index
#posts = policy_scope(Post.all)
authorize #posts
end
def show
#post = Post.find(params[:id])
end
def new
#post = Post.new
authorize #post
end
def create
#post = current_user.posts.build(params.require(:post).permit(:title, :body))
authorize #post
if #post.save
flash[:notice] = "Post was saved"
redirect_to #post
else
flash[:error] = "There was an error saving the post. Please try again"
render :new
end
end
def edit
#post = Post.find(params[:id])
authorize #post
end
def update
#post = Post.find(params[:id])
authorize #post
if #post.update_attributes(params.require(:post).permit(:title, :body))
flash[:notice] = "Post was updated."
redirect_to #post
else
flash[:error] = "There was an error saving the post.Please try again."
render :edit
end
end
end
Here's my application policy:
class ApplicationPolicy
attr_reader :user, :record
def initialize(user, record)
#user = user
#record = record
end
def index?
false
end
def show?
scope.where(:id => record.id).exists?
end
def create?
user.present?
end
def new?
create?
end
def update?
user.present? && (record.user == user || user.admin?)
end
def edit?
update?
end
def destroy?
update?
end
def scope
record.class
end
class Scope
attr_reader :user, :scope
def initialize(user, scope)
#user = user
#scope = scope
end
def resolve
scope
end
end
end
And my post policy:
class PostPolicy < ApplicationPolicy
class Scope < Scope
def resolve
if user.admin? || user.moderator?
scope.all
else
scope.where(:id => user.id).exists?
end
end
end
def index?
user.admin? || user.id?
end
end
Also, is there anywhere I can read or learn more about scope policies with Pundit and authorization on rails?
Make sure to always write the methods to declare the admin and the moderator in your User model if you want to work with Pundit policies.
def admin?
role == 'admin'
end
def moderator?
role == 'moderator'
end
There is a better way to define admins, moderators and members. First do:
rails g migration AddRoleToUsers role:integer
Then in your users model make an enum
enum role: [:member, :moderator, :admin] # add whatever roles you want
The enum will automatically create for each role a
.member? # checks if role is member
.member! # turns the user into a member so like current_user.member!
# and the same for all other roles.
Not sure if this really helps but hope you find it useful!

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