Styjun

I've built a classic Rails API backend that has User, Comment, Sighting. I've set up Comment as Commentable via polymorphic morphic relationship. Incidentally, Sighting is also a join table between User and Animal but Animal is not relevant here.
I am able to create comments via Sighting.first.comments.create() and comment on comments via `Comment.first.comments.create() in Console but when I try to view them in routes, I get not method errors or routing errors. I need to do fetch requests from React so these routes need to work.

My Models:

class Comment < ApplicationRecord

 belongs_to :commentable, :polymorphic => true
 has_many :comments, as: :commentable, dependent: :destroy
end

class Sighting < ApplicationRecord
 has_one_attached :image
 belongs_to :user
 belongs_to :animal
 has_many :comments, :as => :commentable, dependent: :destroy

 def image_filename
 self.image.filename.to_s if self.image.attached?
 end

 def image_attached?
 self.image.attached?
 end


end

class User < ApplicationRecord
 include Rails.application.routes.url_helpers
 has_many :sightings
 has_many :animals, through: :sightings
 has_many :comments, :as => :commentable, dependent: :destroy

 has_secure_password
 has_one_attached :avatar

 def avatar_filename
 self.avatar.filename.to_s if self.avatar.attached?
 end

 def avatar_attached?
 self.avatar.attached?
 end



 validates :username, uniqueness: true

 def attachment_url
 if self.attachment.attached?
 Rails.application.routes.url_helpers.rails_blob_url(self.attachement, only_path: false)
 else
 nil
 end
 end

end

My Controllers:

class Api::V1::CommentsController < ApplicationController
 before_action :find_comment, only: [:index, :update, :destroy]
 before_action :find_commentable


 def index
 @comments = Comment.all
 render json: @comments
 end



 def create
 @comment = @commentable.comments.new(comment_params)
 if @comment.save
 render json: @comment, status: :accepted
 else
 render json: errors: @comment.errors.full_messages , status: :unprocessible_entity
 end
 end


 def update
 @comment.update(comment_params)
 if @comment.save
 render json: @comment, status: :accepted
 else
 render json: errors: @comment.errors.full_messages , status: :unprocessible_entity
 end
 end




 private

 def comment_params
 params.require(:comment).permit(:body, :likes)
 end

 def find_comment
 @comment = Comment.find(params[:id])
 end

 def find_commentable
 @commentable = Sighting.find_by_id(params[:sighting_id])
 if params[:sighting_id]
 @comentables = Comment.find_by_id(params[:comment_id])
 if params[:comment_id]
 end
 end
 end

end

class Api::V1::SightingsController < ApplicationController
 before_action :find_sighting, only: [:update, :show, :destroy]

 def index
 @sightings = Sighting.all
 render json: @sightings
 end

 def show
 render json: @sighting, status: :ok
 end




 def create
 @sighting = Sighting.new(sighting_params)
 # @sighting.image.attach(params[:sighting][:image])
 if @sighting.save
 render json: @sighting, status: :accepted
 else
 render json: errors: @sighting.errors.full_messages , status: :unprocessible_entity
 end
 end


 def update

 # if curr_user.id == @sighting.user_id
 @sighting.update(sighting_params)
 if @sighting.save
 render json: @sighting, status: :accepted
 else
 render json: errors: @sighting.errors.full_messages , status: :unprocessible_entity
 end
 end


 def destroy
 if curr_user.id == @sighting.user_id

 @sighting.delete
 render json: "sighting deleted"
 else
 render json: errors: "You are not authorized to delete"
 end
 end


 private

 def sighting_params
 params.require(:sighting).permit(:title, :body, :likes, :image, :user_id, :animal_id)
 end

 def find_sighting
 @sighting = Sighting.find(params[:id])
 end
end

class Api::V1::UsersController < ApplicationController

 before_action :find_user, only: [:update, :show, :avatar_upload, :destroy]


 def index
 @users = User.all
 render json: @users
 end


 def create

 @user = User.new(
 username: params[:username],
 password: params[:password]
 )
 if @user.save
 encode_token(@user.id)
 render json: user: UserSerializer.new(@user), token: ENV['jwt'], status: :ok
 else
 render json: errors: @user.errors.full_messages
 end
 end


 def show
 if @user
 if curr_user.id == @user.id
 render json: @user
 elsif
 curr_user.id == @user.id
 # @user.avatar.attach(params[:user][:avatar])
 render json: @user
 else
 render json: errors: @user.errors.full_messages , status: :unprocessible_entity
 end
 else
 render json: errors: "User not found!"
 end

 end


 def update

 if curr_user.id == @user.id
 @user.update(user_params)
 # @user.avatar.attach(params[:user][:avatar])
 if @user.save
 render json: @user, status: :accepted
 else
 render json: errors: @user.errors.full_messages , status: :unprocessible_entity
 end
 end
 end

 def avatar_upload
 @user.update(user_params)
 if @user.save
 render json: @user, status: :accepted
 else
 render json: errors: @user.errors.full_messages , status: :unprocessible_entity
 end
end


 def destroy
 if curr_user.id == @user.id
 @user.avatar.purge_later if @user.avatar
 @user.delete
 render json: "user deleted"
 else
 render json: errors: "You are not authorized to delete"
 end
 end

 private

 def user_params
 params.require(:user).permit(:name, :username, :password, :avatar)
 end


 def find_user
 @user = User.find(params[:id])
 end

end

my Serializers

class CommentSerializer < ActiveModel::Serializer

 attributes :id, :body, :likes, :user_id

 belongs_to :commentable, :polymorphic => true
 has_many :comments, as: :commentable, dependent: :destroy

 def user_name
 User.all.find .username
 end

end

class SightingSerializer < ActiveModel::Serializer
 include Rails.application.routes.url_helpers

 belongs_to :user
 belongs_to :animal
 has_many :comments, :as => :commentable, dependent: :destroy


 attributes :id, :title, :body, :likes, :image, :created_at, :user_id



 def image
 rails_blob_path(object.image, only_path: true) if object.image.attached?
 end

end

class UserSerializer < ActiveModel::Serializer
 include Rails.application.routes.url_helpers

 attributes :id, :name, :username, :avatar

 has_many :sightings
 has_many :animals, through: :sightings
 has_many :comments, :as => :commentable, dependent: :destroy


 def avatar
 rails_blob_path(object.avatar, only_path: true) if object.avatar.attached?
 end


end

and My Routes:

Rails.application.routes.draw do
 # For details on the DSL available within this file, see http://guides.rubyonrails.org/routing.html
 post "/rails/active_storage/direct_uploads", to: "direct_uploads#create"

 root to: 'sightings#index'

 namespace :api do
 namespace :v1 do

 resources :users, only: [:index, :show, :create, :update, :destroy] do
 resources :comments
 end

 resources :animals, only: [:index, :show, :update]

 resources :sightings, only: [:index, :show, :create, :update, :destroy] do
 resources :comments
 end

 resources :comments, only: [:create, :update, :destroy] do
 resources :comments
 end

 put "/users/avatar_upload/:id", to: "users#avatar_upload"
 post "/login", to: "auth#login"
 get "/current_user", to: "auth#get_user_from_token"

 end
 end

end

Here is an error for localhost:9000/api/v1/sightings/17/comments

Started GET "/api/v1/sightings/17/comments" for 127.0.0.1 at 2019-03-27 19:15:03 -0400
Processing by Api::V1::CommentsController#index as HTML
 Parameters: "sighting_id"=>"17"
Completed 404 Not Found in 27ms (ActiveRecord: 19.8ms)



ActiveRecord::RecordNotFound (Couldn't find Comment without an ID):

app/controllers/api/v1/comments_controller.rb:42:in `find_comment'

and for localhost:9000/api/v1/sightings

Completed 200 OK in 157ms (Views: 117.3ms | ActiveRecord: 33.9ms)


Started GET "/api/v1/comments" for 127.0.0.1 at 2019-03-27 19:17:07 -0400

ActionController::RoutingError (No route matches [GET] "/api/v1/comments"):

First Error

/api/v1/sightings/17/comments is /api/v1/sightings/:sighting_id/comments

That route has only params[:sighting_id].

It calls before_action :find_comment before running index action and find_comment needs params[:id]

But Api::V1::CommentsController#index does not have params[:id]

So Rails would emit to 'Couldn't find Comment without an ID'

I think that you don't need call a before_action when request to index

Remove :index to only condition

before_action :find_comment, only: [:update, :destroy]

Second Error

 resources :comments, only: [:create, :update, :destroy] do
 resources :comments
 end

this routes does not have :index

Add :index to only condition

 resources :comments, only: [:index, :create, :update, :destroy] do