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

iPaul
page 37 ANTLRInputStream input = new ANTLRInputStream(is); as of ANTLR 4 .8 should be: CharStream stream = CharStreams.fromStream(i...
New
mikecargal
Title: Hands-On Rust (Chapter 11: prefab) Just played a couple of amulet-less games. With a bit of debugging, I believe that your can_p...
New
Mmm
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...
New
HarryDeveloper
Hi @venkats, It has been mentioned in the description of ‘Supervisory Job’ title that 2 things as mentioned below result in the same eff...
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
brunogirin
When running tox for the first time, I got the following error: ERROR: InterpreterNotFound: python3.10 I realised that I was running ...
New
oaklandgit
Hi, I completed chapter 6 but am getting the following error when running: thread 'main' panicked at 'Failed to load texture: IoError(O...
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
mcpierce
@mfazio23 I’ve applied the changes from Chapter 5 of the book and everything builds correctly and runs. But, when I try to start a game,...
New

Other popular topics Top

Devtalk
Reading something? Working on something? Planning something? Changing jobs even!? If you’re up for sharing, please let us know what you’...
1062 22827 403
New
PragmaticBookshelf
Brace yourself for a fun challenge: build a photorealistic 3D renderer from scratch! In just a couple of weeks, build a ray tracer that r...
New
PragmaticBookshelf
Write Elixir tests that you can be proud of. Dive into Elixir’s test philosophy and gain mastery over the terminology and concepts that u...
New
DevotionGeo
I know that these benchmarks might not be the exact picture of real-world scenario, but still I expect a Rust web framework performing a ...
New
Exadra37
I am thinking in building or buy a desktop computer for programing, both professionally and on my free time, and my choice of OS is Linux...
New
siddhant3030
I’m thinking of buying a monitor that I can rotate to use as a vertical monitor? Also, I want to know if someone is using it for program...
New
DevotionGeo
I know that -t flag is used along with -i flag for getting an interactive shell. But I cannot digest what the man page for docker run com...
New
AstonJ
Curious to know which languages and frameworks you’re all thinking about learning next :upside_down_face: Perhaps if there’s enough peop...
New
New
AstonJ
I’ve been hearing quite a lot of comments relating to the sound of a keyboard, with one of the most desirable of these called ‘thock’, he...
New

Sub Categories: