http status code article expiation

comments_controller.rb

class CommentsController < ApplicationController
  
  # v3 example
  def show
    #oop I forget add '#' to comment at line 6 then server will thown error 500
    check paramter is exist
    if !params[:id].present? 
      render json: { response: { data: nil }, success: false} and return
    end
    
    comment = Comment.find_by(id: params[:id])
    render json: { response: { data: comment }, success: true} 
  end 
  
end

http_code.rb

code = { 
  success: 200,
  bad_request: 400,
  unauthorized: 401,
  forbidden: 403,
  not_found: 404,
  internal_server_error: 500,
  bad_gateway: 502,
  service_unavailable: 503 
  }

jq_ajax.js

 $.ajax({ url: '127.0.0.1',
         dataType: 'json',
         type: "POST",
         data: data,
         success: function(data, textStatus, xhr) {
          // do something
         },
         error: function(xhr, textStatus, errorThrown) {
          // do something
         }
   });

jq_article.js

 $.ajax({ url: '127.0.0.1/aritcles/1',
         dataType: 'json',
         type: "GET",
         success: function(data, textStatus, xhr) {
          // this line will show true or false depen on server response
          alert(data.success);
         },
         error: function(xhr, textStatus, errorThrown) {
          // this line no longer user beacase ervery response is 200
          // data.success gose to undefined 
          alert(data.success);
         }
   });

jq_comment.js

 $.ajax({ url: '127.0.0.1/comments/1',
         dataType: 'json',
         type: "GET",
         success: function(data, textStatus, xhr) {
          // this line will show true or false depen on server response
          if(data.sucess) {
            // do someting on webpage
          } else {
            alert('comment ID is missing, please check you data');
            // do process or error handle code gose here
          }
         },
         error: function(xhr, textStatus, errorThrown) {
          // this line will work because server thown 500 and line 9 not working
           alert('comment ID is missing, please check you data');
         }
   });

jq_review.js

$.ajax({ url: '127.0.0.1/reviews/1',
         dataType: 'json',
         type: "GET",
         success: function(data, textStatus, xhr) {
          // do something in web page 
          add_review_to_html(data);
         },
         error: function(xhr, textStatus, errorThrown) {
           alert('review ID is missing, please check you data');
           // other handle
         }
   });

posts_controller.rb

class PostsController < ApplicationController
  
  # v2 example
  def show
    # check paramter is exist
    if !params[:id].present? 
      render json: { response: { data: nil }, success: false} and return
    end
    
    post = Post.find_by(id: params[:id])
    render json: { response: { data: post }, success: true} 
  end 
  
end

render.rb

render status: 200, json: { response: { data: data }, success: true }
render status: 400, json: { response: { data: data }, success: false }

reviews_controller.rb

class ReviewsController < ApplicationController
  
  # v4 example
  def show
    # check paramter is exist
    if !params[:id].present? 
      render status: 400, json: { response: { data: nil }, success: false} and return
    end
    
    review = Review.find_by(id: params[:id])
    render status: 200, json: { response: { data: review }, success: true} 
  end 
  
end

users_controller.rb

class UsersController < ApplicationController
  
  # v1 example
  def index
    user = User.all
    render status: 200, json: { response: { data: user }, success: true} 
  end 
  
end