Create basic Book API with search by ISBN and POST new book.

Author: Juraj Chlebec

Gemfile

@@ -26,6 +26,7 @@ gem 'jbuilder', '~> 2.5'
 group :development, :test do
   # Call 'byebug' anywhere in the code to stop execution and get a debugger console
   gem 'byebug', platforms: [:mri, :mingw, :x64_mingw]
+  gem 'pry-rails'
 end
 
 group :development do
@@ -37,3 +38,5 @@ end
 
 # Windows does not include zoneinfo files, so bundle the tzinfo-data gem
 gem 'tzinfo-data', platforms: [:mingw, :mswin, :x64_mingw, :jruby]
+
+gem 'roar'

Gemfile.lock

@@ -41,8 +41,11 @@ GEM
     arel (8.0.0)
     builder (3.2.3)
     byebug (9.1.0)
+    coderay (1.1.2)
     concurrent-ruby (1.0.5)
     crass (1.0.2)
+    declarative (0.0.10)
+    declarative-option (0.1.0)
     erubi (1.7.0)
     ffi (1.9.18)
     globalid (0.4.0)
@@ -72,6 +75,11 @@ GEM
     nokogiri (1.8.1)
       mini_portile2 (~> 2.3.0)
     pg (0.21.0)
+    pry (0.11.1)
+      coderay (~> 1.1.0)
+      method_source (~> 0.9.0)
+    pry-rails (0.3.6)
+      pry (>= 0.10.4)
     puma (3.10.0)
     rack (2.0.3)
     rack-test (0.7.0)
@@ -103,6 +111,12 @@ GEM
     rb-fsevent (0.10.2)
     rb-inotify (0.9.10)
       ffi (>= 0.5.0, < 2)
+    representable (3.0.4)
+      declarative (< 0.1.0)
+      declarative-option (< 0.2.0)
+      uber (< 0.2.0)
+    roar (1.1.0)
+      representable (~> 3.0.0)
     ruby_dep (1.5.0)
     spring (2.0.2)
       activesupport (>= 4.2)
@@ -120,6 +134,7 @@ GEM
     thread_safe (0.3.6)
     tzinfo (1.2.3)
       thread_safe (~> 0.1)
+    uber (0.1.0)
     websocket-driver (0.6.5)
       websocket-extensions (>= 0.1.0)
     websocket-extensions (0.1.2)
@@ -132,8 +147,10 @@ DEPENDENCIES
   jbuilder (~> 2.5)
   listen (>= 3.0.5, < 3.2)
   pg (~> 0.18)
+  pry-rails
   puma (~> 3.7)
   rails (~> 5.1.4)
+  roar
   spring
   spring-watcher-listen (~> 2.0.0)
   tzinfo-data

app/controllers/api/v1/api_controller.rb

@@ -0,0 +1,5 @@
+module Api::V1
+  class ApiController < ApplicationController
+    # Generic API stuff here
+  end
+end

app/controllers/api/v1/books/crud_controller.rb

@@ -0,0 +1,55 @@
+module Api::V1
+  module Books
+    class CrudController < ApiController
+
+      #  POST /book-add(.:format)          api/v1/books/crud#create
+      def create
+        book = Book.new
+        BookRepresenter.new(book).from_json(request.body.string)
+        book.save!
+
+        render status: 200, json: {
+          status: 200,
+          message: "Book saved!"
+        }
+      rescue ActiveRecord::RecordInvalid => e
+        render status: 422, json: {
+          status: 422,
+          message: "Invalid request! #{e.message}"
+        }
+      end
+
+      #  POST /book-add(.:format)          api/v1/books/crud#create
+      def create
+        book = Book.new
+        BookRepresenter.new(book).from_json(request.body.string)
+        book.save!
+
+        render status: 200, json: {
+          status: 200,
+          message: "Book saved!"
+        }
+      rescue ActiveRecord::RecordInvalid => e
+        render status: 422, json: {
+          status: 422,
+          message: "Invalid request! #{e.message}"
+        }
+      end
+
+      # GET  /:id(.:format)               api/v1/books/crud#read
+      def read
+        book = Book.find_by(id: params[:id])
+
+        if book.nil?
+          render status: 404, json: {
+            status: 404,
+            message: 'Book not found!'
+          }
+        else
+          render json: BookRepresenter.new(book).to_json
+        end
+      end
+
+    end
+  end
+end

app/controllers/api/v1/books/search_controller.rb

@@ -0,0 +1,21 @@
+module Api::V1
+  module Books
+    class SearchController < ApiController
+
+      # GET  /search/isbn/:isbn(.:format) api/v1/books/search#isbn
+      def isbn
+        book = Book.find_by(isbn: params[:isbn])
+
+        if book.nil?
+          render status: 404, json: {
+            status: 404,
+            message: 'Book not found!'
+          }
+        else
+          render json: BookRepresenter.new(book).to_json
+        end
+      end
+
+    end
+  end
+end

app/jobs/application_job.rb

@@ -0,0 +1,5 @@
+class Book < ApplicationRecord
+  validates :title,   presence: true
+  validates :author,  presence: true
+  validates :isbn,    presence: true, uniqueness: true
+end

app/models/book.rb

@@ -0,0 +1,16 @@
+require 'roar/decorator'
+require 'roar/json/hal'
+
+class BookRepresenter < Roar::Decorator
+  include Roar::JSON::HAL
+  include Roar::Hypermedia
+
+  property :id
+  property :title
+  property :author
+  property :isbn
+
+  link :self do
+    "http://books/#{represented.id}"
+  end
+end

app/representers/book_representer.rb

@@ -1,3 +1,15 @@
 Rails.application.routes.draw do
-  # For details on the DSL available within this file, see http://guides.rubyonrails.org/routing.html
+  scope module: 'api' do
+    scope module: 'v1' do
+
+      # Search books API
+      scope 'search'do
+        get   'isbn/:isbn', to: 'books/search#isbn'
+      end
+
+      post 'book-add',      to: 'books/crud#create'
+      get  ':id',           to: 'books/crud#read',  constraints: { id: /[0-9]+/ }
+
+    end
+  end
 end

config/routes.rb

@@ -0,0 +1,11 @@
+class CreateBooks < ActiveRecord::Migration[5.1]
+  def change
+    create_table :books do |t|
+      t.string :author, null: false,  index: true
+      t.string :title,  null: false,  index: true
+      t.string :isbn,   null: false,  index: true, unique: true
+
+      t.timestamps null: false
+    end
+  end
+end

db/migrate/20171016111510_create_books.rb

@@ -0,0 +1,29 @@
+# This file is auto-generated from the current state of the database. Instead
+# of editing this file, please use the migrations feature of Active Record to
+# incrementally modify your database, and then regenerate this schema definition.
+#
+# Note that this schema.rb definition is the authoritative source for your
+# database schema. If you need to create the application database on another
+# system, you should be using db:schema:load, not running all the migrations
+# from scratch. The latter is a flawed and unsustainable approach (the more migrations
+# you'll amass, the slower it'll run and the greater likelihood for issues).
+#
+# It's strongly recommended that you check this file into your version control system.
+
+ActiveRecord::Schema.define(version: 20171016111510) do
+
+  # These are extensions that must be enabled in order to support this database
+  enable_extension "plpgsql"
+
+  create_table "books", force: :cascade do |t|
+    t.string "author", null: false
+    t.string "title", null: false
+    t.string "isbn", null: false
+    t.datetime "created_at", null: false
+    t.datetime "updated_at", null: false
+    t.index ["author"], name: "index_books_on_author"
+    t.index ["isbn"], name: "index_books_on_isbn"
+    t.index ["title"], name: "index_books_on_title"
+  end
+
+end