GraphQL Subscriptions for Tracking Shopify Sales in Real-Time

1. Introduction
   • Importance of real-time sales tracking in e-commerce
   • Overview of GraphQL subscriptions and their benefits for Shopify store owners
2. Understanding GraphQL Subscriptions
   • Basic concepts of GraphQL subscriptions
   • How GraphQL subscriptions differ from traditional polling methods
3. Setting Up Your Node.js Environment
   • Preparing Node.js for using GraphQL subscriptions
   • Necessary packages and tools, such as Apollo Client, @shopify/shopify-api
4. Creating a Subscription Server
   • Setting up an Apollo Server to handle subscriptions
   • Configuring WebSocket connection for real-time data transmission
   • Node.js code example: Initializing a subscription server
5. Defining GraphQL Subscription Schema
   • Designing a GraphQL schema for tracking sales data
   • Node.js code example: Schema definition for sales tracking
6. Implementing Subscription Resolvers
   • Writing resolvers for handling real-time sales updates
   • Node.js code example: Resolver for new sale notifications
7. Frontend Integration
   • Connecting a frontend application to receive updates from GraphQL subscriptions
   • Node.js code example: Frontend subscription setup using Apollo Client
8. Securing Subscriptions
   • Best practices for securing GraphQL endpoints
   • Implementing authentication and authorization for subscription data
9. Handling Connectivity Issues
   • Strategies for managing WebSocket disconnections and retries
   • Techniques to ensure data consistency during network failures
10. Performance Optimization
    • Optimizing subscription performance for handling high traffic
    • Caching strategies and load balancing for scalable real-time data delivery
11. Monitoring and Debugging
    • Tools and practices for monitoring GraphQL subscription performance
    • Debugging common issues in real-time data subscriptions
12. Conclusion
    • Recap of the advantages of using GraphQL subscriptions for real-time sales tracking
    • Encouragement to adopt advanced GraphQL features to boost business operations

const { ApolloServer, gql, PubSub } = require('apollo-server');
const { Shopify } = require('@shopify/shopify-api');

const pubsub = new PubSub();
const SALE_CREATED_TOPIC = 'SALE_CREATED';

const typeDefs = gql`
  type Sale {
    id: ID!
    amount: Float!
    createdAt: String!
  }

  type Subscription {
    saleCreated: Sale
  }
`;

const resolvers = {
  Subscription: {
    saleCreated: {
      subscribe: () => pubsub.asyncIterator([SALE_CREATED_TOPIC])
    },
  },
};

const server = new ApolloServer({ typeDefs, resolvers });

server.listen().then(({ url }) => {
  console.log(`🚀 Server ready at ${url}`);
});

// Simulate a new sale event
function simulateSale() {
  const sale = {
    id: "1",
    amount: 299.99,
    createdAt: new Date().toISOString(),
  };
  pubsub.publish(SALE_CREATED_TOPIC, { saleCreated: sale });
}

setInterval(simulateSale, 10000);  // simulate a sale every 10 seconds