7hoenix

7hoenix

Real-World Event Sourcing:

@autodidaddict

Real World Event Sourcing: Page 105 of version 3 (PDF)

Inconsistent descriptions around whether Aggregates can process events or only commands.

An aggregate’s internal state can change by replaying events that predate the newly deployed aggregate, but that doesn’t alter the timeline, so it’s allowed.

The book seems to not be internally consistent with if aggregates are meant to process events or only commands.

Sometimes the book says that Aggregates execute commands to produce events (with Process Managers doing the inverse), but then quotes like this trickle through and I get a little confused.

I did look at the Commanded api, and it doesn’t seem to provide a way to process events in aggregates.

First Post!

swrenn

swrenn

Hello. I’m also reading this book. I believe aggregates consume events to build internal state and then use that state to vet commands. It looks like apply/2 serves this purpose. There’s an example here.

Where Next?

Popular Pragmatic Bookshelf topics Top

herminiotorres
Hi @Margaret , On page VII the book tells us the example and snippets will be all using Elixir version 1.11 But on page 3 almost the en...
New
joepstender
The generated iex result below should list products instead of product for the metadata. (page 67) iex> product = %Product{} %Pento....
New
jeremyhuiskamp
Title: Web Development with Clojure, Third Edition, vB17.0 (p9) The create table guestbook syntax suggested doesn’t seem to be accepted ...
New
leonW
I ran this command after installing the sample application: $ cards add do something --owner Brian And got a file not found error: Fil...
New
jskubick
I’m under the impression that when the reader gets to page 136 (“View Data with the Database Inspector”), the code SHOULD be able to buil...
New
digitalbias
Title: Build a Weather Station with Elixir and Nerves: Problem connecting to Postgres with Grafana on (page 64) If you follow the defau...
New
Charles
In general, the book isn’t yet updated for Phoenix version 1.6. On page 18 of the book, the authors indicate that an auto generated of ro...
New
dsmith42
Hey there, I’m enjoying this book and have learned a few things alredayd. However, in Chapter 4 I believe we are meant to see the “>...
New
s2k
Hi all, currently I wonder how the Tailwind colours work (or don’t work). For example, in app/views/layouts/application.html.erb I have...
New
New

Other popular topics Top

Devtalk
Hello Devtalk World! Please let us know a little about who you are and where you’re from :nerd_face:
New
New
AstonJ
Inspired by this post from @Carter, which languages, frameworks or other tech or tools do you think is killing it right now? :upside_down...
New
Exadra37
Oh just spent so much time on this to discover now that RancherOS is in end of life but Rancher is refusing to mark the Github repo as su...
New
AstonJ
Seems like a lot of people caught it - just wondered whether any of you did? As far as I know I didn’t, but it wouldn’t surprise me if I...
New
mafinar
Crystal recently reached version 1. I had been following it for awhile but never got to really learn it. Most languages I picked up out o...
New
foxtrottwist
A few weeks ago I started using Warp a terminal written in rust. Though in it’s current state of development there are a few caveats (tab...
New
First poster: joeb
The File System Access API with Origin Private File System. WebKit supports new API that makes it possible for web apps to create, open,...
New
DevotionGeo
I have always used antique keyboards like Cherry MX 1800 or Cherry MX 8100 and almost always have modified the switches in some way, like...
New
AstonJ
This is cool! DEEPSEEK-V3 ON M4 MAC: BLAZING FAST INFERENCE ON APPLE SILICON We just witnessed something incredible: the largest open-s...
New

Sub Categories: