Find category within category model - Rails - ruby-on-rails

When a category is deleted, contents/posts with same category_id also needs be destroyed.
Here is my categories controller.
#Categories Controller
def destroy
authorize #category
#category.destroy
respond_to do |format|
format.html { redirect_to categories_url, notice: 'Category was successfully destroyed.' }
format.json { head :no_content }
end
end
private
def set_category
#category = Category.find(params[:id])
end
def category_params
params.require(:category).permit(:title, :user_id, :image)
end
Inside my Category model, I have added a after_destory.
#Category model
after_destroy :remove_content
private
def remove_content
if Content.exists?(:category_id => self.id)
Content.destroy(the_content)
end
end
def the_content
#the_content = Content.where(category_id: self.id)
end
I use self.id to grab category_id, but the category uses id and title as uri.
def to_param
"#{id} #{title}".parameterize
end
Content belongs to category.
#Content model
class Content < ActiveRecord::Base
has_attached_file :image, styles: { medium: "300x160#", thumb: "100x53#" }, default_url: "/images/:style/missing.png"
validates_attachment_content_type :image, content_type: /\Aimage\/.*\Z/
belongs_to :user
belongs_to :category
def to_param
"#{id} #{title}".parameterize
end
end
How can I grab category_id from CategoriesController without self.id ?

Just use association for this:
classs Category < ActiveReocrd::Base
has_many :contents, dependent: :destroy
dependend: :destroy does exactly what you are trying to achieve. It adds a hook destroying all the contents which belongs to deleted category. Note, do not use #category.delete as it is not triggering any hooks - always use #category.destroy

Like what BroiStaste said, you'd be best using the dependent: :destroy switch in the Category model:
#app/models/category.rb
class Category < ActiveRecord::Base
has_many :contents, dependent: :destroy
This is a very simple principle, in that you're telling ActiveRecord that if you destroy a Category object (which is what you're doing), it should destroy any of the dependent Content objects it has.
From the Docs:
If you set the :dependent option to:
:destroy, when the object is destroyed, destroy will be called on its associated objects.
:delete, when the object is destroyed, all its associated objects will be deleted directly from the database without calling their destroy method.

Related

has_many :through add extra param in join table in one call (object creation)

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.

Rails accepts_nested_attributes_for associated models not created

I have two models (Company and User) that have a belongs_to/has_many relationship.
class Company < ActiveRecord::Base
attr_accessor :users_attributes
has_many :users
accepts_nested_attributes_for :users, allow_destroy: true
end
class User < ActiveRecord::Base
belongs_to :company
end
In my CompaniesController I want to create a new instance of Company along with a group of Users.
class Cms::CompaniesController < ApplicationController
def create
company = Company.new(company_params)
respond_to do |format|
if company.save
format.json { render json: company, status: :ok }
else
format.json { render json: company.errors.messages, status: :bad_request }
end
end
end
private
def company_params
params.require(:company).permit(
:id,
:name,
users_attributes: [
:id,
:_destroy,
:first_name,
:last_name,
:email
]
)
end
end
When I call company.save, I would expect a new instance of Company along with several new instances of User to be saved, depending on how many users I have in my params, however no users are persisted.
Here is a sample of what company_params looks like:
{"id"=>nil, "name"=>"ABC", "users_attributes"=>[{"first_name"=>"Foo", "last_name"=>"Bar", "email"=>"foo#bar.com"}]}
What am I missing here?
Remove attr_accessor:
class Company < ActiveRecord::Base
has_many :users
accepts_nested_attributes_for :users, allow_destroy: true
end
Everything else should work.
--
attr_accessor creates getter/setter methods in your class.
It's mostly used for virtual attributes (ones which aren't saved to the database). Your current setup is preventing you from being able to save the users_attributes param, thus your users are not saving.

Rails create action with multiple belongs_to

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)

Include both joined tables in Rails JSON API call

I am getting the following Active Record Association error when trying to join two tables (with a polymorphic relationship) and include all data from both tables in a JSON API response:
Association named 'categories' was not found; perhaps you misspelled it?
Here is the controller action that I am trying to call:
def index
#items = Item.includes(:categories)
respond_to do |format|
format.json { render :json => #items.to_json }
end
end
And here are the two models that I am trying to join:
class Category < ActiveRecord::Base
attr_accessible :name
has_many :items, :as => :linkable
end
class Item < ActiveRecord::Base
attr_accessible :due_date, :linkable_id, :linkable_type, ...
belongs_to :linkable, :polymorphic => true, :counter_cache => true
end
Specifically, I want to return each Item in the database along with its Category. I have tried everything that I can think of. Any help will be greatly appreciated.
Have you tried :
def index
#items = Item.includes(:linkable).where(:linkable_type => 'Category')
respond_to do |format|
format.json { render :json => #items.to_json(include: :linkable) }
end
end
The name of your association is actually :linkable for the Item model, and not :categories (especially because it's a belongs_to so it would be :category).

Ruby On Rails Pagination and delete :through association

I am running into a strange situation, considering the following models:
class Collection < ActiveRecord::Base
attr_accessible :name, :season, :year
has_many :collection_items_assocs
has_many :items, :through => :collection_items_assocs
end
class Item < ActiveRecord::Base
attr_accessible :name, :reference, :item_type_id
has_many :pictures
has_one :item_type
end
class CollectionItemsAssoc < ActiveRecord::Base
attr_accessible :collection_id, :item_id
belongs_to :item
belongs_to :collection
end
I can successfully retrieve Items associated to a Collection with the following code:
# GET /collections/1
# GET /collections/1.json
def show
#collection = Collection.find(params[:id])
#collection.items = Collection.find(params[:id]).items
respond_to do |format|
format.json { render json: #collection.to_json(:include => {:items => #collection}) }
end
end
But when I try to include pagination (for items) like that
# GET /collections/1
# GET /collections/1.json
def show
#collection = Collection.find(params[:id])
**#collection.items = Collection.find(params[:id]).items.paginate(:page => params[:page],:per_page =>1)**
respond_to do |format|
format.json { render json: #collection.to_json(:include => {:items => #collection}) }
end
end
It works for the following call
/retailapp/collections/1?format=json&**page=1**
Then if I call
/retailapp/collections/1?format=json&**page=2**
the records in the association table CollectionItemsAssoc are deleted
I really don't get it
Thanks for your help
The problem is the code to fetch the items
#collection.items = Collection.find(params[:id]).items
it assigned the fetched items to current collection object.
you need to change the response to support the pagination on associate objects
  def show
   #collection = Collection.find(params[:id])
respond_to do |format|
format.json {
json_hash = #collection.as_json
json_hash[:items] = #collection.items.paginate(:page => params[:page],:per_page =>1).as_json
render json: json_hash.to_json
}
end
Additionally you can overwrite to_json method inside Collection model.

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