Clojurians Log v2

I have an embedded environment (arm v7l) and want to get a cljs repl using only node. Anyone an idea how to get there? using shadow-cljs I can compile cljs to js and run it on the target platform, but the target platform has no java

@b you can just run shadow-cljs on your machine. all you need is a websocket connection from node back to your machine

@thheller I wouldn't even know where to start with that, do you have a pointer?

noob question: this resets my-atom:

(reset! my-atom 300)

(#(reset! my-atom %) 2)

well I don't know enough about your runtime environment

do you copy the code there manually? is it some sort of mounted disk? sshfs or so?

ok it seems it was something in my keybindings that was evaluating the wrong thing. Never mind 😄

I copy the code manually via scp and run it via ssh "node script.js"

in my mind I would have to deploy a nrepl-server cljs bundle, which I can then invoke via "node nrepl.js" and that way I can connect to it from my dev environment

that would not work with shadow-cljs

the output of the shadow-cljs build is designed to connect back to the running shadow-cljs watch

so you can totally have that running on your machine

while copying the output to the other thing

I'd typically recommend using something like sshfs though

avoid copying all the things all the time

you just might need to tune a couple settings since the :node-script output usually assumes that is running on the machine it was compiled on

I don't actually know if this will work at all but in theory it can

okay I think I get the gist

sshfs to the target platform, so my "out"-dir is on the target platform and then I invoke shadow-cljs with watch and tune some parameters so my dev environment IP is used to connect back from node when I run node on the target platform

exactly

I will give it a try, thanks

probably want to set :devtools-url, see the docs

defaults to use localhost which won't work

I had this problem before, if I don't use release then I get an error when trying to run the script.js on the target

Error: ENOENT: no such file or directory, open '/home/root/.shadow-cljs/builds/script/dev/out/cljs-runtime/goog.debug.error.js'

you need to configure :output-dir as well as :output-to

otherwise it defaults to using the .shadow-cljs temp dir which you probably haven't mounted

now I get a new error when running "node script.js" on the target platform: Error: Cannot find module 'ws'

npm install ws

I assume here you have :output-dir "out" or so and that dir is mounted

you can cd out; npm init -y; npm install ws on your machine

okay now there is no error, now we're at the part where it tries to connect to localhost

(I've set :devtools-url to http://my-internal/ip

okay I manually edited the global.CLOSURE_DEFINES property of shadow.cljs.devtools.client.env.server_host and it connects! Very cool

probably configured :devtools-url in the wrong place

should be in :devtools

manually editing will override it on every compiled which will get annoying

don't forget the port too so :devtools {:devtools-url "<http://your-ip:9630>"} in your build config of course

yeah it works! this is incredible! 🙂 thanks a lot

Hello! Two questions: 1 - Can I use cljsjs packages along with npm packages in the same project? 2 - If I use npm packages do I have to import react if I'm using reagent?

1 - yes, https://clojurescript.org/news/2017-07-12-clojurescript-is-not-an-island-integrating-node-modules

2 - no, react comes bundled with reagent - but you can exclude it and add your own, see :exclusions here https://github.com/reagent-project/reagent

The answer to 2 depends on the build tool. With shadow-cljs, you don't have to exclude anything - you just need to install React via NPM.

Interesting reagent atom behavior that I am stuck on. I'm a few callbacks deep in a callback stack, and am trying to reset an atom to the argument passed into the callback. A call to reset! does nothing, while I am still unable to print the value. I wrote a little test function

(defn reset-and-print [atom val]
  (print val)
  (reset! atom val))

it is a bad idea to use cljsjs AND npm at the same time. you'll very likely have things duplicated and possibly conflicting with each other.

I tried with a normal atom, not an r/atom and I see the same behavior

probably the atom is being reset but you didn't close over it and so its recreating the component with a fresh atom each time and so it appears like nothing is changing.

(defn my-component-with-state []
	(let [showing (r/atom false)]
	  (fn [] 
	   	(if @showing 
	   	  [:div "Showing"]
	   	  [:button {:on-click #(reset! showing true)} "Not showing"]))))

My atom is top level though

ok

I added a watch to it, and it is not getting updated

I'm trying to make a MWE

what is MWE ?

minimal working example

:thumbsup:

Apparently my repl wasn't connected to the right browser session.

All good! Thank you for your help @rutledgepaulv

np. glad it was something silly