Merge pull request #81 from iaebots/polymorphic-relations

Polymorphic relations

app/controllers/api/v1/comments_controller.rb

@@ -3,13 +3,13 @@
 module Api
   module V1
     class CommentsController < ApplicationController
-      before_action :find_post, only: :create
-      before_action :new_comment, only: :create
-      before_action :find_comment, only: %i[show destroy]
-      before_action :find_bot, only: :destroy
+      before_action :find_commentable, only: :create
+      before_action :create_comment, only: :create
+      before_action :find_comment, only: :destroy
+      before_action :find_commenter, only: :destroy
       before_action :require_authorization!, only: :destroy
 
-      # POST /:username/posts/:post_id/resource
+      # POST /api/v1/:username/posts/:post_id/comment
       def create
         if @comment.save
           render json: { status: 'success', message: 'Comment created', data: @comment }, status: :created
@@ -18,7 +18,7 @@ def create
         end
       end
 
-      # DELETE /:username/posts/:post_id/resource/:id
+      # DELETE /api/v1/:username/posts/:post_id/comment/:id
       def destroy
         if @comment.destroy
           render json: { status: 'success', message: 'Comment deleted', data: @comment }, status: :accepted
@@ -27,44 +27,44 @@ def destroy
         end
       end
 
-      # GET /:username/posts/:post_id/resource/:id
-      def show
-        render json: { status: 'success', message: 'Comment loaded', data: @comment }, status: :ok
-      end
-
       private
 
-      # Find post by post_id
-      def find_post
-        @post = Post.find(params[:post_id])
+      # Find commentable. If :post_id exists, commentable is a post
+      def find_commentable
+        @commentable = Post.find(params[:post_id]) if params[:post_id]
       end
 
       # Define what params are permitted
       def comment_params
-        params.permit(:body)
+        params.require(:comment).permit(:id, :body, :post_id)
       end
 
       # Find comment by id
       def find_comment
         @comment = Comment.find(params[:id])
       end
 
-      # Define new comment content
-      def new_comment
-        @comment = Comment.new(comment_params)
-        @comment.bot = @current_bot
-        @comment.post = @post
+      # Create new comment with body passed as param
+      # Bot as commenter
+      # Post as commentable
+      def create_comment
+        @comment = @commentable.comments.create(commenter_id: @current_bot.id, commenter_type: 'Bot',
+                                                body: params[:comment][:body])
       end
 
-      # Find comment's bot
-      def find_bot
-        @bot = @comment.bot
+      # Find comment's commenter
+      def find_commenter
+        @commenter = @comment.commenter
       end
 
-      # Verify if bot owns comment (is authorized)
+      # Return if current_bot is equal to commenter (comment's owner)
+      #
+      # Render unauthorized otherwise
       def require_authorization!
+        return if @current_bot == @commenter
+
         render json: { status: 'error', message: 'Resource does not belong to you' },
-               status: :unauthorized unless @current_bot == @bot
+               status: :unauthorized
       end
     end
   end

app/controllers/api/v1/likes_controller.rb

@@ -3,43 +3,55 @@
 module Api
   module V1
     class LikesController < ApplicationController
-      before_action :find_post
+      before_action :find_likeable
       before_action :find_like, only: :destroy
 
-      # POST /:username/posts/:post_id/like
+      # POST /:username/posts/:post_id/like if like belongs to a post
+      #
+      # POST /:username/posts/:post_id/comments/:comment_id/like if like belongs to a comment
       def create
         if already_liked?
           render json: { status: 'error', message: 'Already liked', data: nil }, status: :unprocessable_entity
         else
-          @post.likes.create(bot_id: @current_bot.id)
-          render json: { status: 'success', message: 'Post liked', data: @post }, status: :created if @post.save
+          @likeable.likes.create(liker_id: @current_bot.id, liker_type: 'Bot')
+          render json: { status: 'success', message: "#{@likeable.class.name} liked", data: @likeable }, status: :created if @likeable.save
         end
       end
 
-      # DELETE /:username/posts/:post_id/like
+      # DELETE /:username/posts/:post_id/like if like belongs to a post
+      #
+      # DELETE /:username/posts/:post_id/comments/:comment_id/like if like belongs to a comment
       def destroy
         if already_liked?
-          render json: { status: 'success', message: 'Post unliked', data: @post }, status: :accepted if @like.destroy
+          if @like.destroy
+            render json: { status: 'success', message: "#{@likeable.class.name} unliked", data: @likeable }, status: :accepted
+          end
         else
           render json: { status: 'error', message: 'Cannot unlike', data: nil }, status: :unprocessable_entity
         end
       end
 
       private
 
-      # Find post by post_id
-      def find_post
-        @post = Post.find(params[:post_id])
+      # Find likeable
+      # Likeable is a Post if post_id is present and comment_id is not present
+      # This happens because comments belong to posts, therefore post_id is always going to be present
+      def find_likeable
+        if params[:post_id] && !params[:comment_id]
+          @likeable = Post.find(params[:post_id])
+        elsif params[:comment_id]
+          @likeable = Comment.find(params[:comment_id])
+        end
       end
 
       # Find current bot's like by current_bot.id
       def find_like
-        @like = @post.likes.find_by(bot_id: @current_bot.id)
+        @like = @likeable.likes.where(liker_id: @current_bot.id, liker_type: 'Bot').first
       end
 
-      # Check if current bot already liked post
+      # Check if current bot has already liked current resource
       def already_liked?
-        Like.where(bot_id: @current_bot.id, post_id: params[:post_id]).exists?
+        @likeable.likes.where(liker_id: @current_bot.id, liker_type: 'Bot').exists?
       end
     end
   end

app/controllers/api/v1/posts_controller.rb

@@ -35,7 +35,7 @@ def destroy
 
       # Define permitted params
       def post_params
-        params.permit(:body, :media)
+        params.permit(:body, :media, :username)
       end
 
       # Define new post content
@@ -47,7 +47,7 @@ def new_post
       # Set post and its content (comment and likes)
       def set_post
         @post = Post.find(params[:id])
-        @comments = Comment.where(post_id: @post.id)
+        @comments = @post.comments.where(commentable_id: @post.id, commentable_type: 'Post').first
         @likes = @post.likes.count
       end
 
@@ -61,9 +61,9 @@ def set_response
       end
 
       def require_authorization!
-        unless @current_bot == @post.bot
-          render json: { status: 'error', message: 'Resource does not belong to you' }, status: :unauthorized
-        end
+        return if @current_bot == @post.bot
+
+        render json: { status: 'error', message: 'Resource does not belong to you' }, status: :unauthorized
       end
     end
   end

app/models/bot.rb

@@ -2,8 +2,8 @@
 
 class Bot < ApplicationRecord
   has_many :posts, dependent: :destroy
-  has_many :comments, dependent: :destroy
-  has_many :likes, dependent: :destroy
+  has_many :comments, as: :commenter, dependent: :destroy
+  has_many :likes, as: :liker, dependent: :destroy
 
   mount_uploader :avatar, AvatarUploader
 

app/models/comment.rb

@@ -1,8 +1,10 @@
 # frozen_string_literal: true
 
 class Comment < ApplicationRecord
-  belongs_to :post
-  belongs_to :bot
+  belongs_to :commentable, polymorphic: true
+  belongs_to :commenter, polymorphic: true
+
+  has_many :likes, as: :likeable, dependent: :destroy
 
   validates_presence_of :body
   validates_length_of :body, maximum: 512 # validates length of  a comment

app/models/like.rb

@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
 class Like < ApplicationRecord
-  belongs_to :post
-  belongs_to :bot, optional: true
+  belongs_to :likeable, polymorphic: true
+  belongs_to :liker, polymorphic: true
 end

app/models/post.rb

@@ -3,8 +3,8 @@
 class Post < ApplicationRecord
   belongs_to :bot
 
-  has_many :comments, dependent: :destroy
-  has_many :likes, dependent: :destroy
+  has_many :comments, as: :commentable, dependent: :destroy
+  has_many :likes, as: :likeable, dependent: :destroy
 
   mount_uploader :media, MediaUploader
 

config/routes.rb

@@ -1,29 +1,29 @@
 # frozen_string_literal: true
 
 Rails.application.routes.draw do
-
   namespace 'api' do
     namespace 'v1' do
       # posts
-      resources :posts, only: %i[create]
+      resources :posts, only: :create
 
       get '/:username/posts/:id', to: 'posts#show'
       delete '/:username/posts/:id', to: 'posts#destroy'
 
-      # posts/comments
-      get '/:username/posts/:post_id/comment/:id', to: 'comments#show'
+      # Comments that belongs to posts
       post '/:username/posts/:post_id/comment', to: 'comments#create'
       delete '/:username/posts/:post_id/comment/:id', to: 'comments#destroy'
 
-      # posts/likes
+      # Likes that belongs to posts
       post '/:username/posts/:post_id/like', to: 'likes#create'
       delete '/:username/posts/:post_id/like', to: 'likes#destroy'
 
+      # Likes that belongs to comments
+      post '/:username/posts/:post_id/comments/:comment_id/like', to: 'likes#create'
+      delete '/:username/posts/:post_id/comments/:comment_id/like', to: 'likes#destroy'
+
       # bots
       resources :bots, param: :username
 
-      resources :comments
-
       # likes
       resources :likes, param: :post_id
     end