PragProg Customers

Real Time Phoenix Errata P47: missing {} on channel creation causes blocking error

kentbull

kentbull

Real Time Phoenix Errata P47: missing {} on channel creation causes blocking error

As of 2020-11-25 The syntax of channel.push(...) should be updated to include a second parameter.
As written the book states on page 47:

channel.push("ping")
    .receive(...)

This causes an error that precedes and prevents joining the channel in addition to preventing the reception of any messages back from the server:

image
image492×151 15.3 KB

A slight modification allows success:

channel.push("ping", {})
    .receive(...)

This error is likely due to a contract change in the Phoenix channel library.

3 comments
#errata/book-real-time-phoenix
5 964 3

Marked As Solved

sb8244

sb8244

Author of From Ruby to Elixir and Real-Time Phoenix

Hello,

Thanks for this report. You are correct. It looks like a change was introduced that assumes payload is an object, although the book uses it as undefined for that example.

I’m going to see if it’s intended that payload cannot be undefined.

Best,
Steve

2
Post #2

Also Liked

sb8244

sb8244

Author of From Ruby to Elixir and Real-Time Phoenix

Hi @kentbull. I submitted a PR to Phoenix that was accepted. This should stop being an issue when the next patch of Phoenix 1.5 is released. When I first checked this bug out, I missed that the documentation still showed channel.push("event") as valid syntax.

1
Post #3
kentbull

kentbull

That’s cool, I’m glad we caught it. Great book by the way, just finished Part 1 and am working on Part 2.

1
Post #4

Where Next?

View thread on forum
View Real Time Phoenix's book portal
Post errata for this book
Post a suggestion for this book
Post a question about this book
Post a review about this book
Home PragProg Customers
#errata/book-real-time-phoenix
5 964 3
Last post

Popular Pragmatic Bookshelf topics Top

jon
PragProg Customers

The Pragmatic Programmer, 20th Anniversary Edition errata
Some minor things in the paper edition that says “3 2020” on the title page verso, not mentioned in the book’s errata online: p. 186 But...
#errata/book-the-pragmatic-programmer-20th-anniversary-edition
10 2636 9
New
sdmoralesma
PragProg Customers

Web Development with Clojure, Third Edition: migrations/create not working: p159
Title: Web Development with Clojure, Third Edition - migrations/create not working: p159 When I execute the command: user=> (create-...
#question/book-web-development-with-clojure-third-edition
5 1084 2
New
raul
PragProg Customers

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 1302 3
New
joepstender
PragProg Customers

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 1800 20
New
adamwoolhether
PragProg Customers

Distributed Services With Go: Unable to pass readiness/liveness checks. (page 210, 215)
I’m not quite sure what’s going on here, but I’m unable to have to containers successfully complete the Readiness/Liveness checks. I’m im...
/book-distributed-services-with-go
5 1420 5
New
brunogirin
PragProg Customers

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 1306 1
New
jwandekoken
PragProg Customers

Programming Phoenix LiveView: Live Upload Match Error
Book: Programming Phoenix LiveView, page 142 (157/378), file lib/pento_web/live/product_live/form_component.ex, in the function below: d...
#errata/book-programming-phoenix-liveview
7 1158 10
New
EdBorn
PragProg Customers

Agile Web Development with Rails 7: (page 70)
Title: Agile Web Development with Rails 7: (page 70) I am running windows 11 pro with rails 7.0.3 and ruby 3.1.2p20 (2022-04-12 revision...
#question/book-agile-web-development-with-rails-7
0 1129 1
New
roadbike
PragProg Customers

Programming Machine Learning: Setting up your system (p 13)
From page 13: On Python 3.7, you can install the libraries with pip by running these commands inside a Python venv using Visual Studio ...
#question/book-programming-machine-learning
1 989 3
New
bdarla
PragProg Customers

SQL Antipatterns, Volume 1: Volume 2?
Is there any plan for volume 2? :slight_smile:
#question/book-sql-antipatterns-volume-1
4 673 3
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 5463 41
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
#pragprog#ios#game-dev#macos/swift#published-book#apple/book-apple-game-frameworks-and-technologies
30 7995 10
New
brentjanderson
General Dev>Hardware

Moonlander Keyboard (Mechanical) (Ergonomic) (Split) (Ortholinear)
Bought the Moonlander mechanical keyboard. Cherry Brown MX switches. Arms and wrists have been hurting enough that it’s time I did someth...
#hardware/keyboards#moonlander#mechanical-keyboards#ortholinear#ergonomic
212 17779 90
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 5961 4
New
DevotionGeo
General Dev>Dev Chat

The V Programming Language
The V Programming Language Simple language for building maintainable programs V is already mentioned couple of times in the forum, but I...
#programminguages/v
21 13874 7
New
Maartz
General Dev>Dev Chat

Roc Language - a new purely functional programming language built for speed and ergonomics
Hi folks, I don’t know if I saw this here but, here’s a new programming language, called Roc Reminds me a bit of Elm and thus Haskell. ...
#programminguages#functional-programming
49 5164 14
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 5837 0
New
AstonJ
Backend>Questions

Psql: error: connection to server on socket "/tmp/.s.PGSQL.5432" failed: No such file or directory
If you’re getting errors like this: psql: error: connection to server on socket “/tmp/.s.PGSQL.5432” failed: No such file or directory ...
#macos/rails/postgresql
1 5553 1
New
PragmaticBookshelf
Backend>Learning Resources

Ash Framework
Explore the power of Ash Framework by modeling and building the domain for a real-world web application. Rebecca Le @sevenseacat and ...
pragprog.com
#pragprog/elixir#published-book/ash/book-ash-framework
15 7555 9
New
AstonJ
AI>Chat

Post your DeepSeek results
Curious what kind of results others are getting, I think actually prefer the 7B model to the 32B model, not only is it faster but the qua...
/deepseek
15 4275 15
New
Back to top

Latest in Real-Time Phoenix

Real-Time Phoenix Portal ❯

PragProg Customers

Pragmatic Bookshelf PragProg Customers ❯

Latest on Devtalk

Devtalk ❯

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.

Honeybadger

Real-time error tracking, performance insights, and observability for devs.

EEF

Supporting innovation across the BEAM ecosystem.

coders51

We build reliable cloud platforms for business-critical systems.

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 move you from confusion to "Aha, now I get it!"

Linux New Media

Publishing Linux Magazine, ADMIN, and MakerSpace for 25+ years.

View all our sponsors ❯

Categories:

Sub 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.

Honeybadger

Real-time error tracking, performance insights, and observability for devs.

EEF

Supporting innovation across the BEAM ecosystem.

coders51

We build reliable cloud platforms for business-critical systems.

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 move you from confusion to "Aha, now I get it!"

Linux New Media

Publishing Linux Magazine, ADMIN, and MakerSpace for 25+ years.

View all our sponsors ❯

We're in Beta

About us Mission Statement See our Roadmap