Handling High-Volume Ticket Scanning in React Native: A Case Study from the Saudi Arabia First Division League (FDL)
Tags: reactnative, ticketing, achieveone, expo
Published: 2023-09-16 02:25:22

The Saudi Arabia First Division League (FDL) is a prominent event, attracting thousands of passionate football fans. Ensuring a smooth check-in process for such a large audience is crucial. Let's delve into a real-world challenge faced during one of these events and explore the solution implemented to overcome it.

### The Challenge

During one of the FDL matches, Easyticket Scan app(a component from Achieveone Group ticketing suite) was used to scan and verify the tickets of attendees. Given the stature of the event, a massive turnout was expected. The task was to scan and check in about three thousand tickets consecutively using iPhone devices.

However, as the event proceeded, a peculiar issue arose. After scanning a barcode, the scanner component in the app disappeared, making it impossible to scan the next ticket without manually triggering the scanner. This glitch, while seemingly minor, could lead to long queues, frustrated fans, and a tarnished event experience.

### The Diagnosis

Initial investigations pointed towards potential memory leaks or unintended state changes in the React Native application. Given the volume of scans, even a tiny leak could accumulate over time, leading to degraded performance or unexpected behaviors. The primary suspects were:

**State Management**: The barcode scanner's visibility was controlled by the application's state. An unintended state change could make the scanner disappear.
**Memory Leaks**: Continuous scanning without proper cleanup might lead to memory accumulation, affecting the app's performance.
**Component Lifecycle**: Components might be re-rendering or unmounting unexpectedly, leading to the disappearance of the scanner.

### The Solution

1. **State Management Refinement**: The state transitions were refined to ensure that the scanner only disappears once a barcode is successfully scanned and does not reappear until explicitly triggered.

2. **Memory Profiling**: Tools like React Native Debugger and Xcode's Instruments were used to profile the app for potential memory leaks.

3. **Component-Level Checks**: Ensured that components, especially the barcode scanner, were not unmounting unintentionally. The component's lifecycle was optimized to prevent unnecessary re-renders.

4. **User Experience (UX) Refinements**: A clear UX flow was established. After scanning a ticket, a clear prompt was provided to the user to scan the next ticket, ensuring seamless consecutive scans.

### Extra Tips for High-Volume Scanning Apps

1. **Optimize State Transitions**: Ensure that state transitions are minimal and only occur when necessary. This reduces the chances of unintended behaviors.

2. **Regular Profiling**: Especially in high-volume scenarios, regularly profile the app to check for memory leaks or performance bottlenecks.

3. **Feedback Mechanism**: Provide clear feedback to the user after each scan, ensuring they know the result (success/failure) and the next steps.

4. **Hardware Considerations**: Ensure that the devices used for scanning are optimized for performance. Close unnecessary background apps and ensure sufficient battery life.

5. **Fallback Options**: Always have a manual check-in option in case of technical glitches.

### Conclusion
The case of the FDL ticket scanning challenge underscores the importance of thorough testing, especially in scenarios with high operational demands. By understanding the challenge, applying systematic solutions, and adhering to best practices, the event's check-in process was streamlined, ensuring that football fans could focus on what truly mattered - enjoying the match.

Reference: [Achieveone Group](https://www.linkedin.com/posts/achieveonegroup_excited-to-announce-our-successful-collaboration-activity-7104088813714485248-yowU?utm_source=share&utm_medium=member_desktop)