1 files changed, 31 insertions, 0 deletions
diff --git a/gn2/wqflask/app_errors.py b/gn2/wqflask/app_errors.py
new file mode 100644
index 00000000..c6081e08
--- /dev/null
+++ b/gn2/wqflask/app_errors.py
@@ -0,0 +1,31 @@
+"""Handle errors at the application's top-level"""
+from flask import flash, redirect, current_app, render_template
+from authlib.integrations.base_client.errors import InvalidTokenError
+
+from gn2.wqflask.oauth2 import session
+from gn2.wqflask.decorators import AuthorisationError
+
+def handle_authorisation_error(exc: AuthorisationError):
+    """Handle AuthorisationError if not handled anywhere else."""
+    current_app.logger.error(exc)
+    return render_template(
+        "authorisation_error.html", error_type=type(exc).__name__, error=exc)
+
+def handle_invalid_token_error(exc: InvalidTokenError):
+    flash("An invalid session token was detected. "
+          "You have been logged out of the system.",
+          "alert-danger")
+    session.clear_session_info()
+    return redirect("/")
+
+__handlers__ = {
+    AuthorisationError: handle_authorisation_error,
+    InvalidTokenError: handle_invalid_token_error
+}
+
+def register_error_handlers(app):
+    """Register all error handlers."""
+    for klass, handler in __handlers__.items():
+        app.register_error_handler(klass, handler)
+
+    return app