Unlocking Real-Time Communication in Oracle APEX with WebSockets

Oracle Application Express (APEX) is a powerful low-code development framework that lets you build robust web applications on top of an Oracle database, But in today’s world of instant updates and dynamic web experiences, traditional polling methods for data exchange can feel sluggish. That’s where WebSockets shine.

What are WebSockets?

WebSockets are a communication protocol that provides a persistent, full-duplex connection between a web browser and a server. This means:

• Bidirectional Communication: Unlike HTTP, where the client initiates requests, both the server and client can send data at any time.
• Real-time Updates: Changes are pushed to the client without the need for constant polling.
• Low Overhead: WebSockets reduce the overhead compared to repeated HTTP requests, making them efficient for frequent updates.

Why WebSockets in Oracle APEX?

Here are some compelling use cases for WebSockets in your APEX applications:

• Real-time Data Dashboards: Update charts, graphs, and visualizations instantly as your database changes, without requiring page refreshes.
• Live Collaboration: Build features like shared whiteboards, where changes made by one user are instantly visible to others.
• Chat Systems: Implement robust chat applications for real-time communication among users.
• Progress Indicators: Provide fine-grained progress bars for long-running processes, updating in real-time.
• Notifications: Send timely alerts and notifications to users without manual refreshes.

How to Implement WebSockets in Oracle APEX

While APEX doesn’t have a built-in WebSocket server, there are a couple of ways to integrate WebSockets:

1. Oracle REST Data Services (ORDS) with WebSockets: ORDS offers experimental WebSocket support. You’ll need to configure this on the ORDS side and use JavaScript on the APEX front-end to manage the WebSocket connection.
2. External WebSocket Server: Utilize a dedicated WebSocket server (like a Node.js server with Socket.io) for flexibility. Your APEX application can interact with it using PL/SQL and AJAX to send and receive messages.

Example: Creating a Simple APEX Chat with WebSockets

Let’s outline the steps involved in using an external WebSocket server for a chat application:

1. Set up a WebSocket Server: You’d create a Node.js server using a library like Socket.io to handle WebSocket connections and broadcast messages.
2. APEX Front-end: Design your chat interface in APEX with a text input and a message display area. Use JavaScript to establish the WebSocket connection and handle message sending and receiving.
3. APEX Back-end: Create PL/SQL procedures to interact with the WebSocket server (likely using APEX_WEB_SERVICE to make calls to the Node.js server)

Important Considerations

• Security: Properly secure your WebSocket endpoints like any other web service to prevent unauthorized access.
• Scalability If you’re expecting a large number of concurrent connections, consider how you’ll scale your WebSocket server.