REST API vs GraphQL

In this very simple example we’re comparing Rest API and GraphQL on the email management application.

Very good examples from folks from Shopify: https://shopify.dev/docs/api/admin/migrate

Understanding GraphQL

GraphQL is a query language for APIs developed by Facebook that provides a more efficient, flexible, and powerful alternative to traditional REST APIs. With GraphQL, clients can specify exactly which data they need, reducing over-fetching and under-fetching of data common in REST APIs. GraphQL also allows clients to retrieve data from multiple resources in a single request, improving performance and reducing network overhead.

Benefits of Using GraphQL

Migrating from a REST API to GraphQL in your Ruby on Rails application offers several advantages:

1. Efficient Data Fetching: GraphQL enables clients to request only the data they need, reducing the amount of data transferred over the network and improving performance.

2. Flexible Querying: With GraphQL, clients can specify complex queries to retrieve data from multiple resources in a single request, eliminating the need for multiple round trips to the server.

3. Strongly Typed Schema: GraphQL uses a strongly typed schema to define the structure of the API, providing clear documentation and validation of data types and relationships.

4. Improved Developer Experience: GraphQL provides a self-documenting API, interactive query exploration, and built-in introspection, making it easier for developers to understand and work with the API.

Migration Steps to GraphQL

Now, let’s walk through the steps to migrate your email management system from a REST API to GraphQL in your Ruby on Rails application.

Step 1: Install GraphQL Gem

Start by adding the graphql gem to your Gemfile and running bundle install to install the gem.

gem 'graphql'

Step 2: Define GraphQL Schema

Define a GraphQL schema that represents the data types and relationships relevant to email management in your application.

# app/graphql/types/email_type.rb
module Types
  class EmailType < GraphQL::Schema::Object
    field :id, ID, null: false
    field :subject, String, null: false
    field :body, String, null: false
    field :sender, UserType, null: false
    field :recipient, UserType, null: false
    # Define other fields and relationships
  end
end

Step 3: Implement Query Resolvers

Implement query resolvers to fetch data from your database and resolve GraphQL queries.

# app/graphql/queries/emails_query.rb
module Queries
  class EmailsQuery < GraphQL::Schema::Resolver
    type [Types::EmailType], null: false

    def resolve
      Email.all
    end
  end
end

Step 4: Expose GraphQL Endpoint

Expose a GraphQL endpoint in your Rails application to accept incoming queries and execute them against your GraphQL schema.

# config/routes.rb
Rails.application.routes.draw do
  post '/graphql', to: 'graphql#execute'
end

Implementation of REST API for Email Management

Now, let’s compare the GraphQL approach with the implementation of a REST API for email management in a Ruby on Rails application.

Step 1: Define Routes

Define routes in your Rails application to handle CRUD operations for emails.

# config/routes.rb
Rails.application.routes.draw do
  resources :emails
end

Step 2: Implement Email Controller

Implement a controller to handle email-related actions such as creating, reading, updating, and deleting emails.

# app/controllers/emails_controller.rb
class EmailsController < ApplicationController
  def index
    @emails = Email.all
    render json: emails
  end

  def show
    @email = Email.find(params[:id])
    render json: email
  end

  # Implement other CRUD actions
end

Step 3: Define Email Model

Define an ActiveRecord model to represent emails and their attributes in your database.

# app/models/email.rb
class Email < ApplicationRecord
  # Define email attributes and associations
end

Conclusion

Migrating from a REST API to GraphQL for email management in your Ruby on Rails application offers numerous benefits, including efficient data fetching, flexible querying, and improved developer experience.

While both approaches have their merits, GraphQL provides a modern and powerful alternative to traditional REST APIs, enabling you to optimize client-server communication and deliver exceptional user experiences.

Embrace GraphQL and empower your application with enhanced performance, flexibility, and scalability in email management.

Happy coding!