I saw this in an example... brings up a question, ...

# javascript

[Gunslingor]

I saw this in an example... brings up a question, how does one change an external interface declared already? The examples just seem to show inheritance.

// Simple warn notifier
      var origWarn = console.warn;
      toastr.options = {
        closeButton: true,
        preventDuplicates: true,
        showDuration: 250,
        hideDuration: 150
      };
      console.warn = function (msg) {
        if (msg.indexOf('[undefined]') == -1) {
          toastr.warning(msg);
        }
        origWarn(msg);
      };

[Big Chungus]

You can redeclare it and both will bind to same js (or rather ts) interfaces

[Gunslingor]

hmm... I realized console was an "interface" in the std lib so I tried overriding the function, but I don't think it worked, maybe because of the public val... js("") worked but is ugly of course. Here is the std lib declaration, will try to re-declare as you suggest.

/**
 * Exposes the [console API](<https://developer.mozilla.org/en/DOM/console>) to Kotlin.
 */
@Suppress("NOT_DOCUMENTED")
public external interface Console {
    public fun dir(o: Any): Unit
    public fun error(vararg o: Any?): Unit
    public fun info(vararg o: Any?): Unit
    public fun log(vararg o: Any?): Unit
    public fun warn(vararg o: Any?): Unit
}

/**
 * Exposes the [console API](<https://developer.mozilla.org/en/DOM/console>) to Kotlin.
 */
public external val console: Console

[Gunslingor]

Yeah, I think that wouldn't work either... I need to redefine the actual external interface, this is the problem:

console.warn = function (msg) {}

Kotlin doesnt seem to allow it.. thinks warn should be warn() and then doesn't get the reassignment.

[Gunslingor]

I might be close to a solution

[Big Chungus]

What about external interface with your stuff and then external val console: YourFancyExternalInterface

[Gunslingor]

Trying everything, failing. I don't think there is a way to do this in Kotlin, redefine an external interface (that is obviously defined externally).

[Gunslingor]

I need to be able to do this:

override external val console: Notifier

but can't =(

[Big Chungus]

Ah i see, you want to override external fun with kotlin code, right? You can do it with extersion functions

[Gunslingor]

extersion function, is that like a crevortis function?

[Big Chungus]

fun Console.log() = ...

[Big Chungus]

Extension*

[Gunslingor]

hmm... sort of, but even then, I would extend from

kotlin.js.console

which is a bunch of externals... so I'd be trying to extend a library of external declarations, one val and one interface. The only way to extend the interface would be to create a NEW class (since its an interface, i think) and inherit from it which I did... but it doesn't need extension it needs to be override, which I did... but I still run against the same problem, reassign the JS console functions.

To clarify: The goal here is to be able to see Toastr alerts AND console warnings for ALL console warnings submitted BY ANYTHING, not just my code 😃

[Big Chungus]

Ah, i see, then just add some js code into your resources and do it there. Or just execute it in main as raw js via js() function

[Big Chungus]

Either way you'd be doing js overriding via js, don't think kotlin supports overriding js stuff

[Gunslingor]

yeah, js("") is the solution... but then I ask myself, what advantage is kotlin providing me with if it's less flexible than the destination and forces me to put real production code in resources or a string... kinda crazy.

[Gunslingor]

So I waste time.

[Gunslingor]

Don't really understand why that works either, or how. I mean I know that if I try to reference kotlinJS variables in the js() string it fails.

[Big Chungus]

Well it kas its tradeoffs. If you find yourself doing js() often, then drop kotlin, otherwise i think it's still worth it

[Gunslingor]

ok. thanks

[Big Chungus]

Js() only sees global values

[Big Chungus]

I think you can get your kotlin vals visible as well if you annotate them with jsExport and jsName

[Gunslingor]

hmmm: https://stackoverflow.com/questions/54612728/how-to-define-a-global-js-function-in-kotlin

[Gunslingor]

Okay, js() it is, moving on from the abyss of the impossible...