Creating custom error pages
In addition to error handlers in Flask, you can also create custom error pages that provide a better user experience. When an error occurs in your application, the error handler can return a custom error page with information about the error, instructions for resolving the issue, or any other content that may be appropriate.
To create a custom error page in Flask, simply create an error handler as described in the preceding section and return a JSON
response that contains the content for the error page.
For instance, let’s take a look at the JSON
response containing a custom error message in the following code:
@app.errorhandler(404)def not_found(error): return jsonify({'error': 'Not found'}), 404
The preceding code returns a JSON
response containing an error message, along with the corresponding HTTP error codes, when a 404
error occurs. Let’s define the React frontend to handle the UI...