RhoMobile Architecture Overview

Core Components of the Suite

  • RhoElements: For UI and device integration
  • Rhoconnect: Handles server-side sync
  • RhoStudio: IDE for development and debugging
  • Rhodes: Ruby-based app framework with JavaScript integration

RhoMobile uses a hybrid model—HTML/JavaScript UI with Ruby backend logic and native device integration through extensions.

Common Issues and Deep Diagnostics

1. Sync Failures with Rhoconnect

Symptoms: Data does not sync, or sync operations hang indefinitely.

Cause: Often due to token mismatches, stale partitions, or unresponsive Rhoconnect sources.

// Example error log
[ERROR] SourceAdapter: Error in query: undefined method 'find' for nil:NilClass

Fix:

  • Ensure each model's adapter implements query, create, update, delete
  • Reset partition tokens via admin console or API
  • Verify Rhoconnect source configuration for proper credentials and endpoint URLs

2. UI Rendering Issues on Modern Devices

Symptoms: Broken layout, text overlapping, or input fields not responding.

Cause: RhoElements uses outdated WebView components and legacy CSS not compatible with Android 10+ or iOS 14+.

// Legacy meta tag
<meta name="viewport" content="width=device-width">

Fix:

  • Update CSS with modern flexbox or grid layout (avoid floats)
  • Use viewport-fit=cover for newer iOS devices
  • Test layouts on native browser engine of target OS version

3. Barcode Scanner Not Responding

Symptoms: Hardware scanner does not trigger events or crashes the app.

Cause: Improper initialization or deprecated Rho APIs for hardware access.

// Deprecated call
Rho.Barcode.start();

Fix:

  • Use the latest Zebra DataWedge plugin for native barcode capture
  • Ensure permissions are explicitly set for camera and input devices
  • Wrap barcode initialization in document.addEventListener("deviceready")

4. Build Failures with Native Extensions

Symptoms: RhoStudio build fails with missing JNI headers or platform libraries.

Cause: Platform SDK mismatch or outdated NDK references.

// Error
fatal error: jni.h: No such file or directory

Fix:

  • Update Android NDK and point ndk.dir in local.properties
  • Use Rakefile to isolate native extension build steps
  • Recompile native extensions with matching API levels

5. Persistent Session or Cookie Issues

Symptoms: Users are logged out between sessions or session data is not retained.

Cause: RhoMobile apps rely on WebView session memory, which can be cleared by OS updates or aggressive memory cleanup.

Fix:

  • Move session tracking to secureStorage or SQLite
  • Use RhoConnect tokens to rehydrate sessions automatically
  • Audit device logs to ensure cookies are not blocked by WebView security policies

Advanced Fix Strategies

1. Migrating to Cordova Plugins

Problem: Rho extensions are limited and often outdated.

Solution:

  • Use cordova plugin add with wrapper JavaScript for integration
  • Map Rho JS APIs to Cordova equivalents
  • Gradually replace native modules with maintained Cordova counterparts

2. Debugging on Newer Android Versions

Issue: Rho apps crash or fail silently on Android 11+.

Solution:

  • Enable verbose logging in Android Studio logcat
  • Ensure scoped storage compliance for file access
  • Update targetSdkVersion and android:exported attributes as per new manifest requirements

3. Managing Device-Specific APIs

RhoMobile supports hardware APIs that behave differently per manufacturer.

Fix:

  • Encapsulate hardware logic using platform conditionals
  • Use abstraction layers to isolate Motorola/Zebra-specific code
  • Validate capabilities via Rho.System.platform and version checks

Best Practices for RhoMobile in Production

  • Pin versions of Ruby, NDK, SDK, and RhoStudio to prevent build drift
  • Use automated tests with RhoSimulator to catch regressions
  • Maintain clear separation between UI, sync logic, and hardware interactions
  • Implement centralized logging across devices and platforms
  • Schedule periodic audits for third-party libraries and OS compatibility

Conclusion

RhoMobile Suite offers unique strengths in barcode scanning and enterprise mobility, but requires diligence to keep it functional in today's mobile ecosystem. From sync layer debugging to UI modernization and native module upgrades, addressing these advanced issues ensures your RhoMobile applications remain reliable and scalable. With thoughtful migration planning, even legacy RhoMobile projects can evolve alongside modern mobile standards.

FAQs

1. Can RhoMobile apps run on the latest Android versions?

Yes, but they require manifest and WebView updates, including scoped storage and permission handling compliance.

2. How do I troubleshoot Rhoconnect authentication issues?

Use the Rhoconnect admin console to inspect logs, reset partitions, and confirm token validity. Enable verbose logging on the client for clarity.

3. What is the best way to handle offline data in RhoMobile?

Leverage Rhoconnect's offline sync with delta updates, and implement custom conflict resolution handlers for critical models.

4. Is there a migration path from RhoMobile to modern frameworks?

Yes. Many teams migrate progressively to Cordova or React Native by replacing Rho modules with plugin equivalents and decoupling sync logic.

5. Why does the UI look different on new iOS devices?

Outdated CSS and meta viewport tags cause rendering issues on edge-to-edge iPhones. Use modern CSS layout systems and test on native simulators.