Add error page

formula10/controller/error_controller.py

@@ -0,0 +1,17 @@
+from typing import cast
+from flask import redirect, render_template, session
+from werkzeug import Response
+
+from formula10.frontend.template_model import TemplateModel
+from formula10 import app
+
+def error_redirect(error_message: str) -> Response:
+    session["error_message"] = error_message
+    return redirect(f"/error")
+
+@app.route("/error")
+def error_root() -> str:
+    model = TemplateModel(active_user_name=None, active_result_race_name=None)
+    message: str = cast(str, session["error_message"])
+
+    return render_template("error.jinja", model=model, error_message=message)