error-handling – Tarik Billa

How to do error handling with bloc pattern in flutter?

December 29, 2023 by Tarik

This is how we handle it in my team: First we build our main page (The navigation root) like this: @override Widget build(BuildContext context) { return BlocBuilder<SuspectEvent, SuspectState>( bloc: _bloc, builder: (context, state) { if (state.cameras.isEmpty) _bloc.dispatch(GetCamerasEvent()); if (!_isExceptionHandled) { _shouldHandleException( hasException: state.hasException, handleException: state.handleException); } return Scaffold( … We declare the _shouldHandleException like this … Read more

NLog rotate and cleanup logfiles

December 6, 2023 by Tarik

It looks like the problem is the shortdate in your filename definition. See my answer at this question: Delete log files after x days You have to define the filename without the date part fileName=”${basedir}/logs/Log.info.txt

How to report errors in a procedural macro using the quote macro?

December 3, 2023 by Tarik

Apart from panicking, there are currently two ways to reports errors from a proc-macro: the unstable Diagnostic API and “the compile_error! trick”. Currently, the latter is mostly used because it works on stable. Let’s see how they both work. The compile_error! trick Since Rust 1.20, the compile_error! macro exists in the standard library. It takes … Read more

Should I avoid unwrap in production application?

December 2, 2023 by Tarik

While the whole “error handling”-topic is very complicated and often opinion based, this question can actually be answered here, because Rust has rather narrow philosophy. That is: panic! for programming errors (“bugs”) proper error propagation and handling with Result<T, E> and Option<T> for expected and recoverable errors One can think of unwrap() as converting between … Read more

How can I match on a specific io::Error type?

September 22, 2023 by Tarik

This works in Rust version 1.17.0 (and probably back to Rust 1.0): let binary = match file.read_u16::<BigEndian>() { Err(ref e) if e.kind() == std::io::ErrorKind::UnexpectedEof => break, Err(e) => panic!(“Can’t read from file: {}, err {}”, filename, e), Ok(binary) => binary, };

Is there a way to globally catch all unhandled errors in a Blazor single page application?

August 23, 2023 by Tarik

In .NET 6 there is component called ErrorBoundary. Simple example: <ErrorBoundary> @Body </ErrorBoundary> Advanced Example: <ErrorBoundary> <ChildContent> @Body </ChildContent> <ErrorContent Context=”ex”> @{ OnError(@ex); } @*calls custom handler*@ <p>@ex.Message</p> @*prints exeption on page*@ </ErrorContent> </ErrorBoundary> For the global exception handling I see this as an option: Create CustomErrorBoundary (inherit the ErrorBoundary) and override the OnErrorAsync(Exception exception). … Read more

Kubernetes has a ton of pods in error state that can’t seem to be cleared [closed]

August 18, 2023 by Tarik

kubectl delete pods –field-selector status.phase=Failed -n <your-namespace> …cleans up any failed pods in your-namespace.

How to manually return a Result?

August 14, 2023 by Tarik

Error is a trait and you want to return a trait object (note the dyn keyword), so you need to implement this trait: use std::error::Error; use std::fmt; #[derive(Debug)] struct MyError(String); impl fmt::Display for MyError { fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { write!(f, “There is an error: {}”, self.0) } } impl Error for … Read more

How to do error handling in Rust and what are the common pitfalls?

August 9, 2023 by Tarik

Rust generally solves errors in two ways: Unrecoverable errors. Once you panic!, that’s it. Your program or thread aborts because it encounters something it can’t solve and its invariants have been violated. E.g. if you find invalid sequences in what should be a UTF-8 string. Recoverable errors. Also called failures in some documentation. Instead of … Read more

Is try-catch like error handling possible in ASP Classic?

June 6, 2023 by Tarik

There are two approaches, you can code in JScript or VBScript which do have the construct or you can fudge it in your code. Using JScript you’d use the following type of construct: <script language=”jscript” runat=”server”> try { tryStatements } catch(exception) { catchStatements } finally { finallyStatements } </script> In your ASP code you fudge … Read more