assuming you are using Figwheel or some other hot reloading scheme those two can bring you a bit closer to “classic” IDE-centric debugging experience

https://github.com/binaryage/dirac/blob/master/docs/integration.md

@darwin thank you

I realized that i had not included dirac as dependency on my project.. and definitely not in nrepl as middleware. This may be the reason for the issue i mentioned above

I will go through them and try again

no, you were just missing the REPL feature of Dirac, but the debugging part should work independently

unfortunately there are some bugs in source-mapping support in DevTools and some more complex clojurescript-generated javascript code causes confusion in DevTools debugger UI, like this https://github.com/binaryage/dirac/issues/53, also generated code which tends to produce long lines with a lot of javascript statements tends to hit DevTools debugger limits and UX issues (e.g. placing breakpoints to proper locations)

is there a cljs pair programming channel?

I'm using some foreign-libs (bundled by webpack) in my cljs project. Is there any way to let the compiler do tree-shaking/dead code elimination on the foreign js? For example, I'm using only 4 components from materialize-css and don't need the code of the other components.

@burke shadow-cljs does DCE on npm modules. If that's not a option you could just bundle what you need, for example create a webpack project with an entry point index.js:

import { foo , bar } from "foobar-lib";
var exports = {};
exports.foo = foo;
exports.bar = bar;
module.exports = export;

:foreign-libs [{:file "libs/bundle.js"
                 :provides ["foobar-lib"]}]

@fbielejec I think I will try shadow-cljs. Tweaking the webpack entry point seems too manually.

@burke http://www.blog.nodrama.io/shadow-cljs-cider 😉

@burke @fbielejec shadow-cljs does not do much DCE of node_modules. only :simple optimizations are applied to npm sources. you'll still get better result that webpack probably but it mostly depends on what you require.

I hope that It'll be worth the effort. My project is a mix of cljsjs and webpack-bundle(everything that was not available in cljsjs). Unfortunately the cljsjs packages I used aren't in shadow-cljsjs 😫

@burke what do you hope to gain from this? bundle size reduction?

@pesterhazy yes I think so.

personally I'm thinking that running non-closure-aware js libs through GCC is a bit risky. I'd rather have slightly larger bundles and things guaranteed to work (as in the "double bundle" method)

I thought that this is one of the main features of the gcc. I dont know.. is it okay to have cljs app of >2mb?

How do I eval code in a different namespace w/o switching to that namespace?

@burke is that post-gzip? it's the size after gzip that counts

I'm not arguing against using gcc for your cljs deps, only raising a question about applying it to foreign libs

@pesterhazy its pre-gzip. Download time is okay because of gzip compression. But it feels like wasting memory and processing time if the js-interpreter on the client has to interpret 30% that isnt needed in the app. I thought that gcc is able to optimize it, but maybe you're right; better have a working app than a small app

stop talking about GCC as if it only did one thing. running things through GCC can mean many things. 🙂

@burke which cljsjs packages in particular are you using?

@burke ClojureScript / Closure JS Module support can allow transpilation of CJS/ES6 modules to Closure modules which allows Closure optimizations. This is what ClojureScript uses when using Node Modules. But as mentioned by @pesterhazy, this can have problems (not many npm packages work yet) and the feature is experimental.

Cljsjs packages could also use Closure module transpilation but none currently do.

In clojure I seem to be able to do this:

(binding [*ns* (the-ns 'foo.bar)] (eval '(foo)))

I remember some discussion about eval in ClojureScript, I think Planck recently added it, but it’s not an option for the non-self-hosted version…

You can mess with eval in ClojureScript but it ends up needing self-hosted ClojureScript to do it. This might be of interest: https://gist.github.com/mfikes/66a120e18b75b6f4a3ecd0db8a976d84

@mfikes, that at least gave me a pointer to find-ns. 😃

Executing code in another namespace like that is not possible without eval?

Self-hosted seems to be unavailable as an option for my use case.

what is the go-to react component when I need a data table (preferably with collapsible rows) these days?

this seems ok https://react-table.js.org

Yes, that looks very nice. Some of the examples breaks and some get a lot of complaints in the console, but that could be the demo that is out of sync, I guess. Most of it seems to work.

Hi guys, I am wondering what is the idiomatic way of updating a js array within an js object? I have been reading that I should use goog.object/get and goog.object/set for js objects and use aset and aget for js arrays. For example:

#js{:k1 #js [1 2 3] :k2 "v2"}

@jamesthibaudeau I think I would do (aset (.-k1 obj) 0 "new val") or maybe (-> (.-k1 obj) (aset 0 “new val”))

In this problem, is the original object actually meant to be the following?

#js {:k1 #js [1 2 3] :k2 "v2"}

Well, at least it actually works then, @mfikes 😃

We can probably assume so as "js array" was used

@thheller I reviewed the different options a while ago and didn't come up with a clear winner

react-virtualized supports very large tables but isn't a full datatable solution

react-table seems to work well for what I want

cool. it's not even in this list: https://github.com/brillout/awesome-react-components#table--data-grid

ah, just used what came up in google. that list might be useful though. thx.

@mfikes yeah that was what I meant sorry

It’s too bad there is no goog.object/setValueByKeys, but I suppose you can compose a goog.object/getValueByKeys with a goog.object/set to mutate something deeply nested in a JavaScript object.

disregard. it occurs to me I should be able to accomplish almost the same thing with promesa/alet

I required a nodejs library, (require '["crypto" :as crypto]), and now I want to be able to print all of the functions within this namespace. How do I get them? Within the repl, stuff like (ns-publics crypto) are returning {}.

Using lumo repl and clojurescript 1.9.x

@montanonic

cljs.user=> (require 'crypto '[goog.object :as gobj])

cljs.user=> (filter (comp fn? (fn [x] (gobj/get crypto x))) (js/Object.keys crypto))

one way of doing it

Okay, interesting. Thank you. I'll play with that.

Is this more work because it's a foreign import?

I'm guessing yes.

yes

crypto is a Node.js module, not a CLJS namespace

This is very strange... I can't :require any namespaces I've created

clojure.lang.ExceptionInfo: voke.state.events does not exist

One simple thing to check is that your ns declarations match your filesystem paths. Not that I’ve ever made that mistake…I ah…know other people who have.

They definitely do

http://shekels.wtf/i/f1a8be86168b5a65c4ff33a6f956357b.png

that's a jvm exception and your files are cljs

0.0!? good point

The repl itself is definitely cljs, though? :thinking_face:

http://shekels.wtf/i/f3aa18760554b63678b25381ba2e6843.png

eval (class 'map) for example

in cljs "class" is not a thing

voke.core> (class 'map)
----  Compiler Warning on   <cljs form>   line:1  column:2  ----

  Use of undeclared Var voke.core/class

  1  (class 'map)
      ^--- 

----  Compiler Warning  ----
#object[TypeError TypeError: voke.core.class$ is undefined]
nil

Looks right

yes

So why tf am i getting jvm exceptions??

how are you requiring?

(ns voke.core (:require [voke.state.events])

have you tried requiring from the repl?

(require 'voke.state.events)

Same jvm exception

wtf

something weird I notice is that I can't get that error message in any environment I've tried

The rest of the error message comes back to piggieback and figwheel

I'll paste the whole thing

clojure.lang.ExceptionInfo: voke.state.events does not exist
 at clojure.core$ex_info.invokeStatic (core.clj:4739)
    clojure.core$ex_info.invoke (core.clj:4739)
    cljs.repl$ns__GT_input.invokeStatic (repl.cljc:202)
    cljs.repl$ns__GT_input.invoke (repl.cljc:198)
    cljs.repl$load_namespace.invokeStatic (repl.cljc:217)
    cljs.repl$load_namespace.invoke (repl.cljc:208)
    cljs.repl$load_dependencies.invokeStatic (repl.cljc:245)
    cljs.repl$load_dependencies.invoke (repl.cljc:241)
    cljs.repl$evaluate_form.invokeStatic (repl.cljc:547)
    cljs.repl$evaluate_form.invoke (repl.cljc:484)
    cljs.repl$eval_cljs.invokeStatic (repl.cljc:672)
    cljs.repl$eval_cljs.invoke (repl.cljc:665)
    clojure.lang.Var.invoke (Var.java:396)
    figwheel_sidecar.repl$catch_warnings_and_exceptions_eval_cljs.invokeStatic (repl.clj:286)
    figwheel_sidecar.repl$catch_warnings_and_exceptions_eval_cljs.invoke (repl.clj:278)
    clojure.lang.Var.invoke (Var.java:396)
    cljs.repl$repl_STAR_$read_eval_print__6536.invoke (repl.cljc:957)
    cljs.repl$repl_STAR_$fn__6542$fn__6551.invoke (repl.cljc:998)
    cljs.repl$repl_STAR_$fn__6542.invoke (repl.cljc:997)
    cljs.compiler$with_core_cljs.invokeStatic (compiler.cljc:1285)
    cljs.compiler$with_core_cljs.invoke (compiler.cljc:1274)
    cljs.repl$repl_STAR_.invokeStatic (repl.cljc:960)
    cljs.repl$repl_STAR_.invoke (repl.cljc:839)
    cemerick.piggieback$run_cljs_repl.invokeStatic (piggieback.clj:169)
    cemerick.piggieback$run_cljs_repl.invoke (piggieback.clj:155)
    clojure.lang.AFn.applyToHelper (AFn.java:171)
    clojure.lang.AFn.applyTo (AFn.java:144)
    clojure.core$apply.invokeStatic (core.clj:661)
    clojure.core$apply.invoke (core.clj:652)
    cemerick.piggieback$evaluate.invokeStatic (piggieback.clj:259)
    cemerick.piggieback$evaluate.invoke (piggieback.clj:255)
    clojure.lang.Var.invoke (Var.java:381)
    cemerick.piggieback$wrap_cljs_repl$fn__36179$fn__36181$fn__36182.invoke (piggieback.clj:291)
    cemerick.piggieback$enqueue$fn__36165.invoke (piggieback.clj:247)
    clojure.tools.nrepl.middleware.interruptible_eval$run_next$fn__32431.invoke (interruptible_eval.clj:190)
    clojure.lang.AFn.run (AFn.java:22)
    java.util.concurrent.ThreadPoolExecutor.runWorker (ThreadPoolExecutor.java:1149)
    java.util.concurrent.ThreadPoolExecutor$Worker.run (ThreadPoolExecutor.java:624)
    java.lang.Thread.run (Thread.java:748)

I have no idea, maybe put all in a public repo so that someone can give you a hand

Well shit, yeah I'll do that later tonight if I can't fix this on my own

Why do I always get the weird errors

Thanks for trying

everyone gets the weird errors from time to time 🙂

Could someone please explain why I see double vector brackets on some anonymous functions?

Example?

hunting for one ...

Okay, the Matchbox (cljs firebase connector) quick spin has..

`(m/listen-children root [:users :mike :friends] (fn [[event-type data]] (prn data)))`

That's argument destructuring

[[event-type data]] means the function takes a vector argument with two members, event-type and data respectively

Cool. Makes sense. So the arity is technically one, and that one thing is a vector with 2 elements

exactly

awesome. high five

😄

destructuring can get a lot more complicated and useful too though

One example from my code, [{:keys [filename tempfile size]} image]

I do that to get three keys from the image in one line

there's a ton you can do with it

so in that case, image is a map and you're grabbing :filename, :tempfile, and :size ?

mhm

okay, while i have your attention, do you know what the heck is going on here..

https://clojure.org/guides/destructuring Here's the corresponding bible verse to today's lesson

lol corresponding bible verse

I want to say it has something to do with spec, tbh i'm unfamiliar

cool. thanks for taking a look anyway.

just one of those things it's impossible to google for

my name is backslash colon hyphen the 3rd

If you figure out what that is let me know

deal

when* i figure out what it is. >=)

well I found the actual code on the repo

https://github.com/jakemcc/backgammon/blob/master/src/cljs/bg/subs.cljs#L74

woo, here it is! (in the reframe reg-sub code) "syntactic sugar"

https://github.com/Day8/re-frame/blob/master/examples/todomvc/src/todomvc/subs.cljs#L128