Hola Amigos del Rigor! Acabamos con la serie sobre “Named Constructors” con el último video de los cuatro. He creado una lista de reproducción pública con los videos que vaya publicando. La podéis encontrar aquí. Espero que os guste!

#MayTheRigorBeWithYou

Hola Amigos del Rigor! Seguimos con la serie sobre “Named Constructors” con el tercer de los cuatro videos. He creado una lista de reproducción pública con los videos que vaya publicando. La podéis encontrar aquí. Espero que os guste!

#MayTheRigorBeWithYou

Hola Amigos del Rigor! Seguimos con la serie sobre “Named Constructors” con el segundo de los cuatro videos. He creado una lista de reproducción pública con los videos que vaya publicando. La podéis encontrar aquí. Espero que os guste!

#MayTheRigorBeWithYou

Hola Amigos del Rigor! Vamos a arrancar un serie de 4 videos sobre “Named Constructors”. También conocidos como “Semantic Constructors” o “Constructor Methods”. Aquí os dejo el primero.

He creado una lista de reproducción pública con los videos que vaya publicando. La podéis encontrar aquí. Espero que os guste!

#MayTheRigorBeWithYou

After my post about “Good ORMs do not call __construct a.k.a. where to fire my Domain Events”, nice discussions (and trolling) are happening in the Barcelona Engineering Slack Channel. Thanks to everyone for the feedback, ideas and concerns. You are more than welcome! The main concerns are:

1. How do I fetch an Entity from ElasticSearch, using new and without firing the Event?
2. How do I create stubs on the Entity that is firing the Domain Event?
3. What are pros and cons of firing the Domain Event in the __constructor or in the named constructor?

So, I’ll take the original code as a starting point, and I’ll suggest different strategies to answer those questions. 

tl;dr: Entity constructor should be called once in its entire life. That’s why good ORMs don’t use constructor to reconstitute objects from the database. Good ORMs use reflection, deserialization or proxies. So, fire your Domain Events in the constructor.

Last week, I saw a presentation about going from coupled-to-framework code to a Domain-Driven Design approach in a sample application. It was a good talk. However, in my honest opinion, there were some mistakes that are important to address. In order not to troll, I have checked with the speakers to write this post ;).

One of the mistakes, that I would like to point is where a Domain Event about “a new product was created” should be trigger specifically inside the Product Entity.

Speakers were showing a “Video” Entity with a named constructor called “create”. They were calling _new _inside the named constructor and then firing the event. I mean, the Domain Event was not fired inside of the real constructor. Let’s see the code we’re talking about (the whole repository can be found here):