Hi everyone :slightly_smiling_face: I'm new to Kot...

# javascript

[Tiago Nunes]

Hi everyone 🙂
I'm new to Kotlin/JS, and I'm following the docs.

I was testing how I could work with jQuery in kotlin. I followed this steps:
https://kotlinlang.org/docs/reference/js-external-declarations-with-dukat.html

implementation(npm("jquery", "3.5.1"))
implementation(npm("@types/jquery", "3.5.1", generateExternals = true))

However, I got a bunch of compile errors when running gradlew run, errors like:
'addEventListener' overrides nothing
'addEventListener' overrides nothing
'addEventListener' overrides nothing
'addEventListener' overrides nothing
'removeEventListener' overrides nothing
'removeEventListener' overrides nothing

Can dukat not yet convert declarations from @types/jquery 3.5.1?
How then can I use jQuery in kotlin (with declarations)?

[Robert Jaros]

Dukat is still an experimental tool. It just doesn't work perfectly.

[Robert Jaros]

You can try https://github.com/rjaros/jquery-kotlin

[Tiago Nunes]

Nice, I'll check it out, thanks 🙂

[Joffrey]

Could it be this bug?
https://github.com/Kotlin/dukat/issues/417

[Tiago Nunes]

The compilation error was different from the one in the issue, but maybe it's related. It was actually printing more than 500 errors, most referenced missing or unexpected overrides...

[Tiago Nunes]

It works with a simple DefinitelyTyped library e.g. is-odd

[Joffrey]

Ah right, it looks like it's the reverse problem. override modifiers when they should not be present (or missing interface most likely). Well as @Robert Jaros said, the project still has a bunch of quirks. What you can do as well is generate your externals "manually" using the jsGenerateExternals  gradle task, and then fix the declarations yourself by hand.

[Tiago Nunes]

https://github.com/rjaros/jquery-kotlin doesn't really seem to work. jQuery.now() works but jQuery("#root") gives compiler error Unresolved reference. None of the following candidates is applicable because of receiver type mismatch

I've also tried jQuery declaration files from https://github.com/kotlin/js-externals, following the deprecation error message when defining external fun jQuery(selector: String): JQuery , but the run task gives an error that, to me, looks like it isn't prepared for IR compiler.

[Tiago Nunes]

@Joffrey, I will try your solution, thanks

[Tiago Nunes]

I'm getting hundreds of errors in translated files... 😕

[Robert Jaros]

@Tiago Nunes

import pl.treksoft.jquery.jQuery
import pl.treksoft.jquery.invoke

[Tiago Nunes]

@Robert Jaros that was it! IntelliJ didn't suggest me that import, which is weird right? It usually finds the imports for extension functions... maybe it's because it's an inline operator?

[Robert Jaros]

In the earlier version it was an operator inside an external interface with a @nativeInvoke annotation (which was working fine with auto-import). But it was deprecated and the inline extension function is a suggested change.
https://github.com/JetBrains/kotlin/blob/master/libraries/stdlib/js/src/kotlin/annotations.kt#L18
Unfortunately it doesn't work nice with auto-imports.