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# GN3 Error Handling
## Tags
* type: docs, documentation
* status: open, ongoing
* keywords: gn3, error_handling, exceptions, docs, documentation
## Introduction
This documentation explains how GN3 handles errors in the application.
## Notes
GN3 uses app-level error handling in Flask
instead of try and except blocks within individual routes.
## Benefits
* Centralized error management simplifies maintenance by centralizing error handling in one location.
* Ensures uniform behavior across the application, making it more predictable.
* Promotes code reuse by handling errors through shared logic.
* Keeps route functions clean and focused by removing redundant error handling.
* Enhances scalability by efficiently managing error handling as the application grows.
In this approach, errors are registered and handled at the application level. For example:
## Error Handler
```python
def handle_generic(exc: Exception) -> Response:
"""Handle generic exceptions."""
current_app.logger.error(exc)
response = jsonify({
"error": type(exc).__name__,
"error_description": exc.args[0] if exc.args else "Generic Exception",
"trace": traceback.format_exc()
})
response.status_code = 500
return response
```
## Registering Error Handlers at the App Level
```python
def register_error_handlers(app: Flask):
"""Register application-level error handlers."""
app.register_error_handler(NotFound, page_not_found)
app.register_error_handler(Exception, handle_generic)
```
## Flask Route Without Try-Except Blocks
```python
@app.route('/some_route')
def some_route():
# If an error occurs, it is handled at the app level
data = computation()
return jsonify(data)
```
For more examples in GN3, see the link below:
=> https://github.com/genenetwork/genenetwork3/blob/main/gn3/errors.py
Related issues:
=> https://issues.genenetwork.org/issues/error-handling-external-errors
|
