In my rails app I have a User Model where I have an attribute: points
class User < ActiveRecord::Base
attr_accessible :points
has_many :answers
end
Is there a way to make the attribute updated only from specific controller actions?
class AnswersController < ApplicationController
....
def create
#user = current_user
#answer = #user.answers.build(params[:answer])
if #answer.save
#user.points += 10 # <-- I want to make points updatable only from this action
#user.save
else
...
end
...
end
Related
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.
More specifically, if I have two options: do a check in the controller or override an association method in the model, which one should I prefer?
Edit:
class Book < ApplicationRecord
belongs_to :author
def author
super || build_author
end
end
Is the code above ok or should I prefer another solution like the one below?
class BooksController < ApplicationController
def update
set_author
if #book.update_attributes(params[:book])
#redirect
else
#render show page - unprocessable entity
end
end
def set_author
a = Author.where(fields)
#book.author = a || #book.build_author
end
end
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 do I add parameters to methods for rendering the current place in favorites?
I tried this:
class Place < ActiveRecord::Base
has_and_belongs_to_many :users
def in_fav(user)
if user.places.include?Place.find(id)
return true
else
return false
end
end
end
class User < ActiveRecord::Base
has_and_belongs_to_many :places
end
class PlacesController < ApplicationController
places = Place.all
user = User.first
render json: {desc:true, status:1; data: places}.to_json(:methods => :in_fav(user))
end
I find same problem here
attr_accessor :current_user
def is_favorited_by_user?(user=nil)
user ||= current_user
end
#drops.current_user = current_user
render :json => #drops.to_json(:methods => :is_favorited_by_user?)
I don't understand current_user - it's assocciations? and how to use method current_user for collection #drops
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.