In our previous post, “From RPG to REST,” we explored how REST APIs are the foundation for modern integration. Now, let’s dive into the third essential skill from our Seven Must-Have Skills for Building Modern IBM i APIs: JavaScript. While RPG has been the backbone of IBM i development for decades, JavaScript has become equally crucial for modern enterprise applications.
Why JavaScript Matters for IBM i Developers
If you’re an IBM i developer, you might wonder why you should add JavaScript to your toolkit when RPG and COBOL handle your business logic perfectly well. The answer lies in the evolving landscape of enterprise applications. Today’s businesses need to:
- Deliver responsive web interfaces that users expect
- Process data in real-time from multiple sources
- High speed data transformations
- Handle complex asynchronous operations
- Integrate seamlessly with cloud services and web APIs
- Support modern development practices and tools
JavaScript excels in all these areas, and with IBM’s official support for Node.js on IBM i, it’s become a natural complement to your existing skills.
JavaScript vs. RPG: Different Tools for Different Jobs
Think of JavaScript not as a replacement for RPG, but as an additional tool in your development arsenal. Here’s a practical comparison:
RPG excels at:
- High-performance batch processing
- Complex business calculations
- Direct database operations
- System-level integrations
JavaScript shines in:
- Web-based user interfaces
- Real-time data processing
- Asynchronous operations
- API integration
- Data Transformations
- JSON (JavaScript Object Notation) data handling
Getting Started with JavaScript: A Practical Approach
For IBM i developers, the transition to JavaScript can feel like learning a new language (because it is!). However, many programming concepts you already know will transfer over. Let’s look at some examples:
Code Example 1: // RPG-style structured programming in JavaScript function calculateOrderTotal(orderLines) { let total = 0; for (const line of orderLines) { total += line.quantity * line.unitPrice; } return total; }
// Modern JavaScript approach const calculateOrderTotal = orderLines => orderLines.reduce((total, line) => total + (line.quantity * line.unitPrice), 0);
Key JavaScript Concepts for IBM i Developers
Dynamic Typing
Unlike RPG, JavaScript uses dynamic typing. While this might seem scary at first, it offers flexibility when dealing with varied data formats:
Code Example 2: // JavaScript handles different data types automatically const customerNumber = “1234567890”; // String const orderCount = 42; // Number const isActive = true; // Boolean const customerInfo = { // Object name: “ACME Corp”, address: “123 Business Ave” };
Asynchronous Programming
One of JavaScript’s strongest features is its handling of asynchronous operations, which is crucial for web applications:
Code Example 3: async function getCustomerOrders(custNumber) { try { const customer = await fetchCustomerDetails(custNumber); const orders = await fetchCustomerOrders(custNumber); return { customer, orders }; } catch (error) { console.error(‘Error fetching customer data:’, error); throw error; } }
JSON Handling
JavaScript’s native JSON handling makes it perfect for modern API integration:
Code Example 4: // Converting RPG-style fixed-format data to JSON const customerRecord = { CUSTNO: “1234567890”, CUSTNAME: “ACME CORP “, CUSTADDR: “123 BUSINESS AVE ” };
const cleanCustomer = { customerNumber: customerRecord.CUSTNO, name: customerRecord.CUSTNAME.trim(), address: customerRecord.CUSTADDR.trim() };
// Ready for API response const jsonResponse = JSON.stringify(cleanCustomer);
Practical Applications in IBM i Environment
When using JavaScript with IBM i, you’ll often find yourself:
- Building API layers that transform traditional RPG program calls into RESTful endpoints
- Processing and transforming data between different formats
- Implementing modern security protocols
- Creating real-time integrations with web services
Here’s a practical example using Node.js on IBM i:
Code Example 5: const express = require(‘express’); const { dbconn } = require(‘idb-connector’);
const app = express();
app.get(‘/api/customers/:id’, async (req, res) => { const connection = new dbconn(); try { const customer = await queryCustomer(connection, req.params.id); res.json(customer); } catch (error) { res.status(500).json({ error: ‘Internal server error’ }); } finally { connection.close(); } });
Development Tools and Best Practices
To get the most out of JavaScript in your IBM i development:
- Use Visual Studio Code with IBM i development extensions
- Implement proper error handling and logging
- Follow JavaScript best practices and modern coding standards
- Leverage npm packages for common functionality
- Implement proper security measures for web applications
Security Considerations
While JavaScript opens up new possibilities, it also brings security responsibilities. Always:
- Validate and sanitize input data
- Use proper authentication and authorization
- Implement rate limiting for APIs
- Follow secure coding practices
- Keep dependencies updated
Moving Forward with JavaScript
As you begin incorporating JavaScript into your IBM i development toolkit, remember that platforms like Eradani Connect can help bridge the gap between traditional IBM i applications and modern JavaScript-based solutions. These tools can provide:
- Secure integration between RPG and JavaScript code
- Automated API generation
- Enterprise-grade security features
- Performance monitoring and optimization
- Development best practices and patterns
Conclusion
JavaScript is no longer just a language for web browsers – it’s an essential tool for modern enterprise development. As an IBM i developer, adding JavaScript to your skill set opens up new possibilities for creating modern, integrated applications while leveraging your existing RPG expertise.
In our next post, we’ll explore Node.js and how it enables server-side JavaScript execution on IBM i, creating even more possibilities for modern application development.
Ready to start your JavaScript journey? Remember that understanding the fundamentals is crucial, but you don’t have to build everything from scratch. Tools like Eradani Connect can help you leverage JavaScript’s power while maintaining the security and reliability your enterprise applications require.
Have questions about incorporating JavaScript into your IBM i development workflow? We’d love to hear from you!
