Clojurians Log v2

What Clojurescript repl type do people usually use? :o

Really don't quite understand the cider clojurescript workflow - if any

Evaluation within Emacs won't work unless I use weasel is that correct ?

Don’t think weasel is really a thing

there are largely three ways to go about this. figwheel (deprecated but still widely used), figwheel main and shadow-cljs. Clojurescript is a clojure library that compiles cljs files into js files. Evaluating code requires a js context, as clojurescript can only emit code, not evaluate it. This is where figwheel-main and shadow come in. They have all of the filewatchers to keep recompiling, and open websockets to update the javascript environment with the latest code.

for the purposes of CIDER, a cljs repl is a regular clj repl that gets "upgraded". you start a clj repl, and call functions in either figwheel main or shadow that move evaluation from the jvm and into the js context

Hmmm, I'm using shadow-cljs but not sure if im supposed to be able to be able to evaluate code inside cider. I am able to get hot-reloading by saving

you absolutely should be able to. m-x cider-jack-in-cljs should prompt you for a few things. pick shadow and then choose your build and it should just work

Am i supposed to have a project.clj ? Am wondering if it is because I only have shadow-cljs.edn with ..

;; shadow-cljs configuration
{:source-paths
 ["src"]

 :dev-http {8081 "public"}

 :dependencies
 [[reagent "1.0.0"]
  [re-com "2.13.2"]
  [binaryage/devtools "1.0.3"]]

 :builds {:app {:target     :browser
                :output-dir "public/scripts/"
                :asset-path "/scripts/"
                :modules    {:main {:init-fn ura.frontend.core/run}}}}}

that will start a shadow process npx shadow-cljs ... and then at the repl it calls (do (require '[shadow.cljs.devtools.api :as shadow]) (shadow/nrepl-select %s)) for you where the %s is replaced with your build

you only need a project.clj file if you need a lein process

totally fine to just have just a frontend

hmmmm

the equivalent for figwheel main is (do (require 'figwheel.main) (figwheel.main/start %s)), basically the same api

let me try again

this call: (do (require '[shadow.cljs.devtools.api :as shadow]) (shadow/nrepl-select %s)) should be done by cider right ?

correct

just jack-in-cljs

and hopefully just follow the prompts

Is it supposed to change from shadow.user> to cljs.user>

Yeah once you open the browser to your app

Local host 8081 for you according to your file above

I think I have this issue https://shadow-cljs.github.io/docs/UsersGuide.html#missing-js-runtime

Have you opened the browser to your site and seeing your app?

Yeapp. But it doesn't watch the app. Doesn't hot reload. Need to manually start the watch

honest question: can shadow-cljs do something different that makes this easier to understand? seems like A LOT of people struggle with this in cider?

this question never comes up for cursive but somehow the cider jack-in process seems to make this complicated? why?

I think it opens the browser automatically. I don’t understand

maybe it is because most start with the clj experience and the cljs experience is very foreign to most ?

But the symptoms here are strange. If it’s not watching the app. If you change some string In your files does it reload the app and show a bit of ui from shadow?

Oh it opens the browser and the app is there but ill get shadow-cljs - Stale Output! Your loaded JS was not produced by the running shadow-cljs instance. Is the watch for this build running?

Let me try again... hmm

I think I remember seeing that when the browser opens before compilation has finished. The repl should show compiling and then when it finishes

And then just hit refresh in your browser

Now i seem getting sync nrepl timeout. If I do (do (require '[shadow.cljs.devtools.api :as shadow]) (shadow/watch :app) (shadow/nrepl-select :app)) myself, it seems to work . Like on save it will say [:app] configuring build. [:app] Compiling ...

but doesn't actually update the app

that sounds like a configuration problem. did you read through how to set up the init and after-refresh functions?

@zackteo here's how I set things up with deps.edn in case it provides some pointers https://github.com/codeasone/starter-cider-tools-deps-shadow

wait. Emacs setup or shadow-cljs.edn?

you can try this repo here: <https://github.com/dpsutton/asg-ignite-app>. just clone, npm install and then cider-jack-in-cljs, choose shadow, and the app build, then open localhost 3000

I found the cider session handling confusing.

https://code.thheller.com/blog/shadow-cljs/2019/08/25/hot-reload-in-clojurescript.html

having some issues with npm install @dpsutton can't seem to find this tho semver.simplifyRange is not a function

when doing npm install?

yeap

weird. for me ran just fine, added 114 packages

189 verbose stack TypeError: semver.simplifyRange is not a function
189 verbose stack     at Advisory.[calculateRange] (/usr/lib/node_modules/npm/node_modules/@npmcli/metavuln-calculator/lib/advisory.js:191:16)
189 verbose stack     at Advisory.load (/usr/lib/node_modules/npm/node_modules/@npmcli/metavuln-calculator/lib/advisory.js:148:28)
189 verbose stack     at Calculator.[calculate] (/usr/lib/node_modules/npm/node_modules/@npmcli/metavuln-calculator/lib/index.js:59:14)
189 verbose stack     at async Promise.all (index 0)
189 verbose stack     at async Map.[init] (/usr/lib/node_modules/npm/node_modules/@npmcli/arborist/lib/audit-report.js:177:7)
189 verbose stack     at async Map.run (/usr/lib/node_modules/npm/node_modules/@npmcli/arborist/lib/audit-report.js:105:7)

hmmmm

looks like that's in the audit report. there are some advisories in these deps but it doesn't matter for demo purposes

might be fine to just ignore and continue

not sure why my nrepl sync keeps timing out now but probably might be resolved with a restart hmm

one thing you can try is npx shadow-cljs compile app and then try everything. if its timing out due to compilation taking a while, you can kinda help it out

don't know if compilation can cause a timeout or not but something to try

Okay it works so it is my app config

could i ask what is ["react-modal" :as Modal]

yeah evaluation works with your project too

that is a require for the react-modal npm package, what exactly that does I don't know 😉

the hot reload seems to work already. But evaluation still does not work for my project ... hjmmm

Okay cool it works now

@zackteo if working with any npm code, it is good to be aware of the different ways you can translate JS requires to CLJS. There is a useful Table 1: ES6 Import to CLJS Require in this section: https://shadow-cljs.github.io/docs/UsersGuide.html#_using_npm_packages

Oooo! Thank you! So using a string like so is the standard for npm packages?

As an aside, @thheller - I've had to reference and point to that table many times; any chance you can add a page id so one can link to the table directly? It's not immediately "obvious" when you link to the section, because it's below the page fold.

@zackteo yes; the strings are used only for external JS imports