Hey, everyone. Is there anyone used the react navigation as a clojurescript format? It's really confused for me to write it, when the react class component used. For example:

class HomeScreen extends React.Component {
  static navigationOptions = {
    title: 'Home',
    headerStyle: {
      backgroundColor: '#f4511e',
    },
    headerTintColor: '#fff',
    headerTitleStyle: {
      fontWeight: 'bold',
    },
  };
  render() {
    return ...
  };
}

is there a way to ^:exportdefault in ClojureScript?

@nha what would that do?

existing export isn't about JS modules btw, it about preserving an api through advanced compilation

I am hoping to do something like this: https://babeljs.io/en/repl#?babili=false&browsers=&build=&builtIns=false&spec=false&loose=false&code_lz=KYDwDg9gTgLgBAMwK4DsDGMCWEVwCYQDKEAtsDABaYoDmAFCAJRwDeAUHHFOUlLiHABUcAcJABuNgF82bUJFj5gCAIZIANvGTosOOCRUBrYA2btO3GL35CRtidKA&debug=false&forceAllTransforms=false&shippedProposals=false&circleciRepo=&evaluate=false&fileSize=false&timeTravel=false&sourceType=module&lineWrap=true&presets=es2015%2Creact%2Cstage-2&prettier=false&targets=&version=7.5.5&externalPlugins= At the moment my understanding is that it is possible to do (defn ^:export doSomething [...]) but not something for make as above

@godwin.ko it's really the only proper way - anything else breaks caching if you're not careful

@nha we don't really support ES6 stuff (from ClojureScript itself), you should just write some JS if you need to do that for JS consumers

Something like that you mean? (untested)

(js/Object.defineProperty js/exports
                          "__esModule"
                          #js {
                               :value true
                               }
                          )
(js/goog.exportSymbol "exports.default" make)

(yes the idea is to expose a nicer API to JS consumers)

yes use JS tooling - we have some support for ES6 modules but it's not very active and I don't know how much we've look at the export side of things

I was hoping for something else but that’s understandable 🙂 thanks!

we can't do everything 🙂

honestly the only real interest we've had wrt. ES6, is allowing you to write ES6 libs that are Closure aware so they can be a part of your build

stuff like Transit falls into this category

Completely fair 😄 And that makes a lot of sense for transit.

Is there a way in ClojureScript to call a function defined as private, in another namespace, without a warning that it is private? Not a big deal if there isn't -- just curious.

@andy.fingerhut you should be able to use the var pattern from Clojure

I'm learning clojurescript. Coming from backend compiled language, can someone recommend some readings / approaches on ways to avoid runtime exceptions. Even typos are harder to spot in dynamic languages. Thanks.

I tried with-redefs attempting to temporarily reassign the value of function into (or perhaps it was some other function in cljs.core), and it seems not to have taken effect. Is this known limitation of ClojureScript with-redefs?

with-redefs works

Hmmm. Let me see if I can repro.

you should demonstrate something that doesn't work

@andy.fingerhut oh I know - ClojureScript direct links the standard lib

Like this: https://gist.github.com/jafingerhut/63a17a7b9562237954cf4be62bb9fae4

with-redefs does work

but you can't with-redefs any references already in the standard lib

not w/o recompiling the standard lib w/ that off

In the case of the test where I wanted to with-redefs on a function in cljs.core, it was straightforward for me to work around this by calling my own function my-vector instead of vector, and do (def my-vector vector), the code that called my-vector, then with-redefs to temporarily change the definition of my-vector

right

the reason is that redefining the standard lib isn't useful for most users

So this sounds like a similar kind of direct linking that exists for Clojure, then. Makes sense.

but having the standard lib be directly linked is

This kind of with-redefs does work for Clojure, though, at least for calls from user code to core fns. So perhaps ClojureScript has one extra 'level' of direct links in the user's code?

Yeah, just double-checked. The same example in my gist linked above works differently with Clojure/Java, I think because Clojure's direct linking only applies to calls between functions in core, unless you explicitly compile your own code with direct linking enabled, too.

well it seems to me that should work as long as you're doing this in a REPL

feel free to open a minor issue in JIRA w/ this example

if you think so, I'm happy to do that. Also perfectly content if the resolution is only a caveat in the docs somewhere.

I mean it should work at the REPL

just won't work for compiled code

which is probably why it hasn't come up before

how does prepl work in CLJS?

does it actually start an honest-to-goodness socket REPL in the JS process? or does it rely on a socket repl being started in the JVM compiler process and then does something like piggieback?

(I’ve only seen it used in Node.js as an example)

and even if most uses is of the latter piggyback style, is there any “native” support for prepl in CLJS where I could bridge it over websockets or some other protocol?

I don't know about prepl. I recently started using ClojureScript with a Node-based socket REPL, and did some experiments to note that starting the JVM process does not also create a node process until and unless some TCP client connects to the socket REPL TCP port. Then it fires up a new node process.

From that I am inferring that the TCP connection is going to the JVM process, not the node process.

yeah that makes sense

I am hoping there’s some sort of prepl machinery in CLJS as well, where I could build a bridge over websockets or browser messaging protocols to do repl-y things

@lilactown Hi there! Just a small shout-out to thank you for hx! It saves me a lot of troubles when working with third-party libraries relying on react hooks 🙂

my use case is that I am building a dev tool that listens to tap> and interacts with the CLJS process directly. atm I’ve built it with a specific protocol over websockets / Chrome APIs for the exact interactions I need with the user’s runtime state, but I am quickly building just another REPL protocol

how do i check if my code is running is nodejs or a browser? I was thinking (exists? js/window)

@currentoor I'd maybe opt for (and (exists? process) (not (empty? (.-version process))))

Which would yield true for a node environment

@alpox i think mean (and (exists? js/process) (not (empty? (.-version js/process))))?

Yes, sorry 😄

and yes i like that better, js/window can be set when someone tries to write compatible code, this is less likely to accidentally get stomped on

thank you

Yes I was thinking the same. I remember seeing some node environments where js/window was set