About

Blog on development in general, and specifically on .NET, since 2009 (original blog is here).
Created and maintained by Ricardo Peres.
I am a portuguese developer from Coimbra, Portugal, where I graduated in Informatics Engineering from the University of Coimbra.
I am currently Founding Team Lead at Evolve Software Portugal and was a Microsoft Most Valuable Professional (MVP) for Visual Studio and Development Technologies.
I also wrote a few books and maintain some open source software.
Always happy to get feedback and comments, either agreeing with what I say or otherwise!

Popular posts from this blog

Domain Events with .NET

Introduction Domain Events  is a pattern and concept made popular by Domain Driven Design . A Domain Event is something that happened on your system and you want interested-parties to know about. It is a way to publish information in a decoupled, usually asynchronous, way. A publisher publishes (raises) an event, and interested subscribers receive a notification and act accordingly. A subscriber can also be a publisher, of course. In this post I'm going to present a Domain Events library for .NET. It's not the first time that I write about decoupling messages and subscribers in an application, I implemented a few years ago the Postal.NET library which does something similar. Mind you, there are many implementations out there, MediatR coming first to my mind, but this is mine. I obviously got some ideas from other implementations, but mine is substantially different from all the others. Concepts First, a few concepts: An event is just some class that implements IDomainEvent A
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ASP.NET Core Pitfalls – Posting a String

This is another post on my ASP.NET Core pitfalls series . It is actually related to this one  ASP.NET Core Pitfalls – Null Models in Post Requests . What happens if you try to submit a string containing JSON as a POST? I mean, you always submit strings, but this time you don't want for it to be parsed into some class. Like this: [HttpPost] public IActionResult PostString([FromBody] string json) { ... } You may be surprised to find out that this fails with a HTTP 415 Unsupported Media Type . Now, you might be tempted to add an [Consumes] attribute to it, such as: [HttpPost] [Consumes("application/json")] public IActionResult PostString([FromBody] string json) { ... } And this will actually work! The problem is, or could be, that it requires the sender to send the appropriate Content-Type header (" application/json "). Another, better, solution is to just read the string from the from the request stream: [HttpPost] public IActionResult PostString() { using v
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Domain Events with .NET - New Features

Introduction You may remember my post on the Domain Events framework I created, a few days ago. Well, I've been working on it, cleaning things a bit, correcting a few bugs, and I introduced two new features/concept:  Event interceptors can now return a boolean from the BeforePublish event in order to cancel the publication of the event Event transformers Changes to Event Interceptors The changes to the IDomainEventInterceptor / IDomainEventInterceptor<TEvent> interface look like this: public interface IDomainEventInterceptor { ValueTask<bool> BeforePublish(IDomainEvent @event, CancellationToken cancellationToken = default); Task AfterPublish(IDomainEvent @event, CancellationToken cancellationToken = default); } public interface IDomainEventInterceptor<TEvent> where TEvent : IDomainEvent { ValueTask<bool> BeforePublish(TEvent @event, CancellationToken cancellationToken = default); Task AfterPublish(TEvent @event, CancellationToken cancellat
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