Trying to figure out a better way of assigning a review it's associated models.
I have the following classes:
class User < ActiveRecord::Base
has_many :reviews, dependent: :destroy
end
class Review < ActiveRecord::Base
belongs_to :user
belongs_to :restaurant
end
class Restaurant < ActiveRecord::Base
has_many :reviews, dependent: :destroy
end
Pretty straightforward stuff. A review must have a restaurant and a user. My create action looks like this:
def create
#restaurant = Restaurant.find(params[:restaurant_id])
#review = #restaurant.reviews.build(review_params)
#review.user = current_user
if #review.save
redirect_to #restaurant
else
render 'new'
end
end
private
def review_params
params.require(:review).permit(:content)
end
Currently I build the review for the restaurant and then I assign the review's user to the current user.
This all works fine but is there a cleaner way to build the associations?
Is there a way to add additional arguments to the build method alongside the strong params?
I looked at accepts_nested_attributes_for but I couldn't get it to work.
Thanks!
You can use merge in the review_params like below
def review_params
params.require(:review).permit(:content).merge(user_id: current_user.id)
end
so that you can erase this line #review.user = current_user in the create method
In your form, you can put a hidden field with the user_id that you want to assign:
<%= f.hidden_field :user_id, value: #user.id %>
Then, add it to your review_params:
params.require(:review).permit(:content, :user_id)
Related
I'm still somewhat new to Ruby and am having trouble displaying data on the show page from another class. I have two classes, Company and Job. On the Job show page I would like to display the Company's name, website and description from the Company form fields that created/posted the job when a job applicant views the respective job.
Was receiving an error when tinkering with the Job show controller action. Not entirely sure if the company is not being assigned an id when being created or if there's an issue with the show action login in the controller or a model association error on my end. Any help and explanation to resolve this issue is greatly appreciated.
Screenshot for Error Received on Job Show Page
Models
class Company < ApplicationRecord
has_many :jobs
has_many :job_applications, through: :jobs
class Job < ApplicationRecord
belongs_to :user
belongs_to :company, optional: true
has_many :job_applications, dependent: :destroy
class JobApplication < ApplicationRecord
belongs_to :user
belongs_to :job
Controllers
class CompaniesController < ApplicationController
private
# Use callbacks to share common setup or constraints between actions.
def set_company
#company = Company.find(params[:id])
# #company = self.create_company
end
# Only allow a list of trusted parameters through.
def company_params
params.require(:company).permit(:name, :website, :about, :user_id, :avatar)
end
class JobsController < ApplicationController
# GET /jobs/1 or /jobs/1.json
def show
#company = Company.find(params[:user_id])
# #company = Company.all
# #job = Job.find(params[:id])
end
Routes
resources :companies
resources :jobs
resources :jobs do
resources :job_applications
end
Job Show Page
<%= #company.name %>
<%= #company.website %>
<%= #company.about %>
I believe the problem lies in your show method in the JobsController.
It should look something like this:
class JobsController < ApplicationController
# GET /jobs/1 or /jobs/1.json
def show
#job = Job.find(params[:id])
#company = #job.company
end
This might throw some errors since you have optional: true in your relation. Also, I didn't care of n+1 queries since it's just a record, but this could be improved to be only 1 SQL query to the database.
I have the following code letting a user to create a new album through a join table with an extra params (creator).
In order to do it, my controller does 2 requests (one for creating the album object and the collaboration object / the other to update the collaboration object with the extra params).
I would like to know if there is a way to do this call with only one request. (add the extra "creator" params in the same time than the album creation)
Thank you.
albums_controller.rb
class AlbumsController < ApplicationController
def new
#album = current_user.albums.build
end
def create
#album = current_user.albums.build(album_params)
if current_user.save
#album.collaborations.first.update_attribute :creator, true
redirect_to user_albums_path(current_user), notice: "Saved."
else
render :new
end
end
private
def album_params
params.require(:album).permit(:name)
end
end
Album.rb
class Album < ApplicationRecord
# Relations
has_many :collaborations
has_many :users, through: :collaborations
end
Collaboration.rb
class Collaboration < ApplicationRecord
belongs_to :album
belongs_to :user
end
User.rb
class User < ApplicationRecord
has_many :collaborations
has_many :albums, through: :collaborations
end
views/albums/new
= simple_form_for [:user, #album] do |f|
= f.input :name
= f.button :submit
You can just add associated objects on the new album instance:
#album = current_user.albums.new(album_params)
#album.collaborations.new(user: current_user, creator: true)
When you call #album.save ActiveRecord will automatically save the associated records in the same transaction.
class AlbumsController < ApplicationController
def new
#album = current_user.albums.new
end
def create
#album = current_user.albums.new(album_params)
#album.collaborations.new(user: current_user, creator: true)
if #album.save
redirect_to user_albums_path(current_user), notice: "Saved."
else
render :new
end
end
private
def album_params
params.require(:album).permit(:name)
end
end
You are also calling current_user.save and not #album.save. The former does work due to fact that it causes AR to save the associations but is not optimal since it triggers an unessicary update of the user model.
I want show the user email as author of comment, but I see this error "undefined method `email' for nil:NilClass"
comment.rb
class Comment < ActiveRecord::Base
belongs_to :hotel
belongs_to :user
end
user.rb
class User < ActiveRecord::Base
has_many :hotels
has_many :comments
end
hotel.rb
class Hotel < ActiveRecord::Base
belongs_to :user
belongs_to :address
has_many :comments
mount_uploader :avatar, AvatarUploader
accepts_nested_attributes_for :address
end
comments_controller.rb
def create
#hotel = Hotel.find(params[:hotel_id])
#comment = #hotel.comments.new(comment_params)
#comment.user_id = current_user.id
#comment.save
redirect_to #hotel
end
private
def comment_params
params.require(:comment).permit(:user_id, :body, :hotel_id)
end
_comments.html.haml
= div_for comment do
%p
%strong
Posted #{time_ago_in_words(comment.created_at)} ago
%br/
= h comment.user.email
%br
= comment.body
Method
The error that you're calling a method which doesn't exist.
The problem is you're calling a method on an associated object which doesn't exist. You probably don't have any user associated to the comment - thus preventing you from being able to call the email method.
Firstly, you need to make sure you have the correct association. Here's how to do that:
$ rails c
$ comment = Comment.find([id])
$ comment.update(user_id: [your_user_id])
$ exit
This will allow you to associate the comment to a particular user, giving you the ability to call the associated method.
--
Controller
When you save your comment in your controller, you need to assign your user to it. We do this using the strong_params functionality, as its the DRYest way we've found:
#app/controllers/comments_controller.rb
Class CommentsController < ApplicationController
def create
#comment = Comment.new(comment_params)
end
private
def comment_params
params.require(:comment).permit(:your, :comment: attributes).merge(user_id: current_user.id)
end
end
This will allow you to associate the user at save time, giving you the ability to call the methods you need next time you call the record!
Delegate
You'll also benefit from using the delegate method like this:
#app/models/comment.rb
Class Comment < ActiveRecord::Base
belongs_to :user
belongs_to :hotel
delegate :email, to: :user, prefix: true #-> allows you to call `#comment.user_email`
end
This will solve the law of Demeter issue (where you should aim to have one "point" in your calls")
I'm new to Rails. I'm building my first app - simple blog. I have User and Post models, where each user can write many posts. Now I want to add Comment model, where each post can have many comments, and also each user can comment on any post created by any other user.
In Comment model I have
id \ body \ user_id \ post_id
columns.
Model associations:
user.rb
has_many :posts, dependent: :destroy
has_many :comments
post.rb
has_many :comments, dependent: :destroy
belongs_to :user
comment.rb
belongs_to :user
belongs_to :post
So how do I correctly define create action in CommentsController?
Thank you.
UPDATE:
routes.rb
resources :posts do
resources :comments
end
comments_controller.rb
def create
#post = Post.find(params[:post_id])
#comment = #post.comments.create(comment_params)
if #comment.save
redirect_to #post
else
flash.now[:danger] = "error"
end
end
The result is
--- !ruby/hash:ActionController::Parameters
utf8: ✓
authenticity_token: rDjSn1FW3lSBlx9o/pf4yoxlg3s74SziayHdi3WAwMs=
comment: !ruby/hash:ActionController::Parameters
body: test
action: create
controller: comments
post_id: '57'
As we can see it doesnt send user_id and works only if I delete validates :user_id, presence: true string from comment.rb
Any suggestions?
In your way you should put this:
def create
#post = Post.find(params[:post_id])
#comment = #post.comments.create(comment_params)
#comment.user_id = current_user.id #or whatever is you session name
if #comment.save
redirect_to #post
else
flash.now[:danger] = "error"
end
end
And also you should remove user_id from comment_params as strong parameters .
Hope this will help you .
Associations
To give you a definition of what's happening here, you have to remember whenever you create a record, you are basically populating a database. Your associations are defined with foreign_keys
When you ask how to "add comments to User and Post model" - the bottom line is you don't; you add a comment to the Comment model, and can associate it with a User and Post:
#app/models/comment.rb
Class Comment < ActiveRecord::Base
belongs_to :user
belongs_to :post
end
This prompts Rails to look for user_id and post_id in the Comment model by default.
This means if you wanted to create a comment directly, you can associate it to either of these associations by simply populating the foreign_keys as you wish (or use Rails objects to populate them)
So when you want to save a comment, you can do this:
#app/controllers/comments_controller.rb
Class CommentsController < ApplicationController
def create
#comment = Comment.new(comment_params)
end
private
def comment_params
params.require(:comment).permit(:user_id, :post_id, :etc)
end
end
Conversely, you can handle it by using standard Rails objects (as the accepted answer has specified)
Class CommentsController < ApplicationController
before_action :set_user
before_action :set_post
def create
#comment = #post.comments.create(comment_params)
if #comment.save
redirect_to #post
else
flash.now[:danger] = "error"
end
end
private
set_post
#post = User.posts.find(params[:post_id])
end
set_user
#user = User.find(params[:user_id])
end
comment_params
params[:comment].permit()
end
Basically my idea is very simple - I want to create a new cart for each new user. The form itself is generated with scaffold and we're talking rails 4.0.1 here.
Is there a way to do that and if so - how? Maybe you can link me some live examples?
You do not need multiple forms to create multiple objects in Rails controller. Assuming that you have relationships like this:
class User < ActiveRecord::Base
has_many :carts #or has_one :cart
end
class Cart < ActiveRecord::Base
belongs_to :user
end
Then it's perfectly acceptable to do this:
class UsersController < ApplicationController
def new
#user = User.new
end
def create
#user = User.new user_params
if #user.save
#user.carts.create # or #user.create_cart
redirect_to user_path
else
render action: :new
end
end
private
def user_params
params.require(:user).permit(...)
end
end
If the new user form happens to include some cart-specific details, then use fields_for to make them available in the form:
= form_for :user do |f|
... f.blah for user fields ...
= fields_for :cart do |cart_fld|
... cart_fld.blah for cart fields ...
and add cart_params to your controller.