bmads_51

bmads_51

Web Development with Clojure, Third Edition: guestbook.auth functions not invocable (P. 168)

Dmitri Sotnikov @dmitri and Scot Brown @svmbrown

I was trying to execute the following code on p. 168:

user> (in-ns 'guestbook.auth)
#namespace[guestbook.auth]
guestbook.auth> (create-user! “testuser” “testpass”)
1
guestbook.auth> (authenticate-user “testuser” “testpass”)
{:login “testuser”, :created_at #inst “2019-09-20T02:22:53.217-00:00”}
guestbook.auth> (authenticate-user “testuser” “wrongpass”)

but the functions in the guestbook.auth namespace were simply unavailable after I switched to that namespace. I was getting No such var error messages.

After a lot of searching, I stumbled upon this from https://clojure.org/guides/repl/navigating_namespaces

How to make sure a lib is loaded

To make sure that a lib with namespace mylib.ns1 has been loaded in the REPL, you can do any one of the following:

  1. require it directly: (require '[mylib.ns1])
  2. load a namespace which itself requires mylib.ns1 (directly or indirectly).
  3. evaluate manually all the code in the source file mylib.ns1

So I believe this section in the book was too premature. I actually went on to type in the login route code further down on pp. 168-9. Since that login route code loads (a la #2 above) the guestbook.auth namespace, once you jack-in or lein repl you will be able to execute the functions in the guestbook.auth namespace. So I think if the code blocks are reversed, that would help solve this issue.

First Post!

Dmitri

Dmitri

Author of Web Development with Clojure

Yeah, using require would force the namespace to load. Simply doing in-ns will switch to the namespace, but won’t trigger for the functions there to be evaluated. I think you’re right that loading the namespace would be the way to go here to avoid the behavior.

Where Next?

Popular Pragmatic Bookshelf topics Top

jeffmcompsci
Title: Design and Build Great Web APIs - typo “https://company-atk.herokuapp.com/2258ie4t68jv” (page 19, third bullet in URL list) Typo:...
New
jdufour
Hello! On page xix of the preface, it says there is a community forum "… for help if your’re stuck on one of the exercises in this book… ...
New
herminiotorres
Hi! I know not the intentions behind this narrative when called, on page XI: mount() |> handle_event() |> render() but the correc...
New
cro
I am working on the “Your Turn” for chapter one and building out the restart button talked about on page 27. It recommends looking into ...
New
brian-m-ops
#book-python-testing-with-pytest-second-edition Hi. Thanks for writing the book. I am just learning so this might just of been an issue ...
New
adamwoolhether
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...
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
akraut
The markup used to display the uploaded image results in a Phoenix.LiveView.HTMLTokenizer.ParseError error. lib/pento_web/live/product_l...
New
AufHe
I’m a newbie to Rails 7 and have hit an issue with the bin/Dev script mentioned on pages 112-113. Iteration A1 - Seeing the list of prod...
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
Devtalk
Reading something? Working on something? Planning something? Changing jobs even!? If you’re up for sharing, please let us know what you’...
1050 20964 393
New
PragmaticBookshelf
Tailwind CSS is an exciting new CSS framework that allows you to design your site by composing simple utility classes to create complex e...
New
PragmaticBookshelf
Learn different ways of writing concurrent code in Elixir and increase your application's performance, without sacrificing scalability or...
New
New
PragmaticBookshelf
Rails 7 completely redefines what it means to produce fantastic user experiences and provides a way to achieve all the benefits of single...
New
hilfordjames
There appears to have been an update that has changed the terminology for what has previously been known as the Taskbar Overflow - this h...
New
First poster: bot
zig/http.zig at 7cf2cbb33ef34c1d211135f56d30fe23b6cacd42 · ziglang/zig. General-purpose programming language and toolchain for maintaini...
New
First poster: AstonJ
Jan | Rethink the Computer. Jan turns your computer into an AI machine by running LLMs locally on your computer. It’s a privacy-focus, l...
New
AstonJ
This is a very quick guide, you just need to: Download LM Studio: https://lmstudio.ai/ Click on search Type DeepSeek, then select the o...
New

Sub Categories: