Pragmatic>PragProg

Ash Framework: variable assignment mistake (page 38)

mattvanhorn

mattvanhorn

Ash Framework: variable assignment mistake (page 38)

In the “Defining an update action” section
artist = Tunez.Music.get_artist_by_id!(​"​​an-artist-id"​)
should be:
{:ok, artist} = Tunez.Music.get_artist_by_id!(​"​​an-artist-id"​)

Otherwise the next line will fail with an error about resource ID

3 comments
/book-ash-framework#errata
2 52 3

Most Liked

sevenseacat

sevenseacat

Author of Ash Framework

Hi there!

In this case, no it shouldn’t - the bang version of a function (ie. get_artist_by_id! vs. get_artist_by_id) will return the object by itself, not as part of an ok or error tuple.

I’ll check and see if we need a note clarifying this…

2
Post #2

Popular Pragmatic topics Top

ianwillie
Pragmatic>PragProg

Build Websites with Hugo: Code will not run in a working Hugo setup
Hello Brian, I have some problems with running the code in your book. I like the style of the book very much and I have learnt a lot as...
#question/book-build-websites-with-hugo
0 1498 3
New
jesse050717
Pragmatic>PragProg

Web Development with Clojure, Third Edition: Issue adding Shadow CLJS
Title: Web Development with Clojure, Third Edition, pg 116 Hi - I just started chapter 5 and I am stuck on page 116 while trying to star...
#question/book-web-development-with-clojure-third-edition
4 1188 4
New
lirux
Pragmatic>PragProg

The Ray Tracer Challenge: "Computing the normal on a transformed sphere" ebook test
Hi Jamis, I think there’s an issue with a test on chapter 6. I own the ebook, version P1.0 Feb. 2019. This test doesn’t pass for me: ...
#errata/book-the-ray-tracer-challenge
10 1446 5
New
Mmm
Pragmatic>PragProg

Hands-on Rust: Build depending on bracket-lib fails
Hi, build fails on: bracket-lib = “~0.8.1” when running on Mac Mini M1 Rust version 1.5.0: Compiling winit v0.22.2 error[E0308]: mi...
#question/book-hands-on-rust
1 1214 1
New
raul
Pragmatic>PragProg

Distributed Services with Go: Chapter 3 suggestions
Page 28: It implements io.ReaderAt on the store type. Sorry if it’s a dumb question but was the io.ReaderAt supposed to be io.ReadAt? ...
#errata/book-distributed-services-with-go
0 1291 3
New
AleksandrKudashkin
Pragmatic>PragProg

Modern Front-End Development for Rails: B7 no main folder in the source code (page xv)
On the page xv there is an instruction to run bin/setup from the main folder. I downloaded the source code today (12/03/21) and can’t see...
#errata/book-modern-front-end-development-for-rails
2 1425 11
New
joepstender
Pragmatic>PragProg

Programming Phoenix LiveView: errata and remarks Version B2.0
The generated iex result below should list products instead of product for the metadata. (page 67) iex> product = %Product{} %Pento....
#errata/book-programming-phoenix-liveview
0 1798 20
New
gilesdotcodes
Pragmatic>PragProg

Modern CSS with Tailwind: setting up Rails app
In case this helps anyone, I’ve had issues setting up the rails source code. Here were the solutions: In Gemfile, change gem 'rails' t...
#errata/book-modern-css-with-tailwind
3 1273 2
New
leba0495
Pragmatic>PragProg

A Common-Sense Guide to Data Structures and Algorithms, Second Edition: (pg460)
Hello! Thanks for the great book. I was attempting the Trie (chap 17) exercises and for number 4 the solution provided for the autocorre...
#errata/book-a-common-sense-guide-to-data-structures-and-algorithms-second-edition
0 1148 3
New
brunogirin
Pragmatic>PragProg

Python Testing with pytest, Second Edition: InterpreterNotFound error when running tox (page 150)
When running tox for the first time, I got the following error: ERROR: InterpreterNotFound: python3.10 I realised that I was running ...
#errata/book-python-testing-with-pytest-second-edition
0 1297 1
New

Other popular topics Top

AstonJ
General Dev>Dev Chat

Best chairs for developers?
What chair do you have while working… and why? Is there a ‘best’ type of chair or working position for developers?
#workspace#opinions
74 4687 41
New
AstonJ
Science/Tech>Tech Chat

What are you watching?
Or looking forward to? :nerd_face:
#community
480 9177 251
New
PragmaticBookshelf
Game Dev>Learning Resources

Apple Game Frameworks and Technologies
Design and develop sophisticated 2D games that are as much fun to make as they are to play. From particle effects and pathfinding to soci...
pragprog.com
/swift#pragprog/book-apple-game-frameworks-and-technologies#published-book#macos#game-dev#ios#apple
30 3131 10
New
First poster: bot
Backend>In The News

Bit – A modernized Git CLI written in Go
github.com
#git/go
1 5376 0
New
Exadra37
macOS>Chat

Your Mac Isn't Yours - worse, it spies on you and sends it home unencrypted
On modern versions of macOS, you simply can’t power on your computer, launch a text editor or eBook reader, and write or read, without a ...
sneak.berlin
#macos#macs#apple#privacy#mac-privacy#big-sur
24 3445 24
New
AstonJ
Backend>Questions

Erlang's not installing on macOS Big Sur "You are natively building Erlang/OTP for a later version of MacOSX than current version"
Just done a fresh install of macOS Big Sur and on installing Erlang I am getting: asdf install erlang 23.1.2 Configure failed. checking ...
/erlang#asdf#macos#big-sur
10 5398 8
New
AstonJ
Backend>Chat

How to install Ruby 3 with ASDF
In case anyone else is wondering why Ruby 3 doesn’t show when you do asdf list-all ruby :man_facepalming: do this first: asdf plugin-upd...
/ruby#asdf
11 5145 4
New
Margaret
General Dev>Sales

Get 50% off these PragProg books during our Think Again Sale
Think Again 50% Off Sale » The theme of this sale is new perspectives on familiar topics. Enter coupon code ThinkAgain2021 at checkout t...
#community#pragprog/elixir/book-a-common-sense-guide-to-data-structures-and-algorithms-second-edition/book-programming-machine-learning/book-the-ray-tracer-challenge/book-forge-your-future-with-open-source/book-software-design-x-rays#algorithms/book-testing-elixir#machine-learning#sale/book-concurrent-data-processing-in-elixir/book-intuitive-python
8 5842 2
New
PragmaticBookshelf
Community>In The Spotlight

Spotlight: Chris Pine (Author)
A Hero’s Journey with Chris Pine @chrispine Chris Pine, author of Learn to Program, Third Edition, discusses his journey to beco...
#author-spotlight/book-learn-to-program-third-edition/ruby
81 3261 26
New
AstonJ
General Dev>Code Editors

Doom-Emacs: Can't find emacs in your PATH
If you get Can't find emacs in your PATH when trying to install Doom Emacs on your Mac you… just… need to install Emacs first! :lol: bre...
#macos/emacs#doom-emacs
4 4659 0
New
Back to top

Latest in PragProg

Ash Framework B4.0: Typo (page 83)
PragProg Customers
Hotwire Native for Rails Developers: Collected Errata from our class at the University of Chicago
PragProg Customers
Agile Web Development with Rails 7 p1.0—May2023: foreman Gem (page 73)
PragProg Customers
The Definitive ANTLR 4 Reference: No download link provided for TestSimple.java (Page 240)
PragProg Customers
Programming Phoenix LiveView: Wrong closing element tag (page 106)
PragProg Customers
Programming Phoenix LiveView: Typo (page 103)
PragProg Customers
Programming Phoenix LiveView: Wrong HTML comment tag in example (page 102)
PragProg Customers
Programming Phoenix LiveView: typo missing word (page 101)
PragProg Customers
Agile Web Development with Rails 8 B7.0: order_mailer_test failing (page 196)
PragProg Customers
Simplicity: Let’s Change Our World — Again
PragProg Customers
Simplicity: "detail"→"derail" (page 74, B2.0)
PragProg Customers
Agile Web Development with Rails 8: Page 9
PragProg Customers
Kotlin Coroutine Confidence: Code does not run (pg 225)
PragProg Customers
Agile Web Development with Rails 8 B7.0: partials folder (page 151)
PragProg Customers
Kotlin Coroutine Confidence: Change function name, maybe (pg 182)
PragProg Customers
Modern Front-End Development for Rails, Second Edition: can't get code to run
PragProg Customers
Kotlin Coroutine Confidence: Book & source code do not match (pg 180)
PragProg Customers
Kotlin Coroutine Confidence: Add formatter off/on comments (pg 162)
PragProg Customers
Kotlin Coroutine Confidence: What's the IntelliJ IDEA inspection? (pg 133 & 141)
PragProg Customers
Kotlin Coroutine Confidence: Add `parallel/v9` (pg 125)
PragProg Customers

View all threads ❯

Latest (all)

Symfony v7.3.0-BETA2 released!
Backend Official News
Actix web-v4.11.0, http-v3.11.0 and awc-v3.7.0 released!
Backend Official News
Cell Mates: Extracting Useful Information From Tables for LLMs
AI In The News
Odin, A Pragmatic C Alternative with a Go Flavour
Backend In The News
What's new in Swift 6.2?
iOS In The News
New Tool: lsds - List All Linux Block Devices and Settings in One Place - Tanel Poder Consulting
Linux In The News
Kodee’s Kotlin Roundup: Compose Multiplatform for iOS is Stable (Plus AI, Web, and More!)
Backend Official News
Write the most clever code you possibly can
In The News
Dasung Paperlike 13K is a 13.3 inch E Ink color monitor - Liliputing
In The News
V weekly.2025.19 released!
Backend Official News
Wikidive - AI-Guided Wikipedia Exploration
AI In The News
Node.js v24.0.1 released!
Backend Official News
Mind-reading AI recreates what you're looking at with amazing accuracy
AI In The News
Why do LLMs have emergent properties?
AI In The News
Announcing Ivar: Ruby’s Missing Instance Variable Typo Warnings
Backend In The News

View all threads ❯

We ❤️ helpful members!

We reward our most helpful members via our MOTM scheme - by giving away a whopping 25 books per year!

Member of the Month

Devtalk Sponsors

Pragmatic Bookshelf

Practical resources that improve the lives of professional developers.

Erlang Solutions

We build trusted fault-tolerant systems that scale to billions of users.

Manning Publications

Develop your skills with books, videos, and courses.

AppSignal

Catch errors, track performance, monitor hosts and more.

WyeWorks

Enabling companies to succeed by building software people love.

Pragmatic Studio

Courses that'll move you from confusion to "Aha, now I get it!"

View all our sponsors ❯

Categories:

Popular Portals

Devtalk Sponsors

Pragmatic Bookshelf

Practical resources that improve the lives of professional developers.

Erlang Solutions

We build trusted fault-tolerant systems that scale to billions of users.

Manning Publications

Develop your skills with books, videos, and courses.

AppSignal

Catch errors, track performance, monitor hosts and more.

WyeWorks

Enabling companies to succeed by building software people love.

Pragmatic Studio

Courses that'll move you from confusion to "Aha, now I get it!"

View all our sponsors ❯

We're in Beta

About us Mission Statement See our Roadmap