I am just trying to get my first Compose WASM app ...

# webassembly

[Michael Paus]

I am just trying to get my first Compose WASM app running in the browser. The app was generated via the Kotlin Multiplatform Wizard | JetBrains. Running it locally in the browser via wasmJsBrowserRun works without problem in Firefox and Chrome (latest versions) but when I create a distribution via wasmJsBrowserDistribution and upload it to my own server I just get a white page when I call the corresponding URL. The page seems to load but in the developer tools of the browser I see many lines like this. Does anyone know what the reason for this is and how it can be cured?

wasm streaming compile failed: TypeError: WebAssembly: Response has unsupported MIME type '' expected 'application/wasm'

[PHondogo]

Just guess: may be your server doesn't have mapping for wasm file extention to content type. Check in browser network development tools what content type have response for wasm file resource.

[Michael Paus]

In the network analysis view files with the extension “wasm” have the type “wasm” too, if that’s what you mean.

[PHondogo]

What value have response header Content-Type

[PHondogo]

For request for fetching wasm file

[Michael Paus]

I am not a web developer and have no idea where to find this information you are looking for. Maybe it is faster if you just look at this URL https://mpmediasoft.de/test/AIPBrowserExp/index.html
I’d be happy if you could point me to a solution 😇.

[PHondogo]

I'll on mobile browser now. I'll help you within couple of hours when reach to laptop.

[Robert Jaros]

https://blog.toddlichty.com/serving-a-wasm-file-from-apache/

[Michael Paus]

Thanks @Robert Jaros. But I doubt that this is the problem. (I don’t access to the server configuration. I can only upload files to it.) I have another, older example running on the same server side by side with the example from above and this works without problem. https://mpmediasoft.de/test/PolySpiralMpp/ It uses Compose Kotlin with JS and not WASM but it contains the file skiko.wasm and that works without problem. So, I doubt that the server settings are wrong.

[Robert Jaros]

In both cases, your server doesn't return the correct content-type header for the wasm file. There is even the same message in the browser console. There is a difference - in the older example this is only a warning and in the newer it's an error. Perhaps there is some fallback in the old skiko.js. Anyway, fixing the server configuration is the correct way to address this issue.

[Michael Paus]

Ok, thanks a lot. I will see how I can get that fixed.

[Michael Paus]

It works now 🎉. I don’t have access to the /etc/mime.types file as suggested in the above article but I can place

AddType application/wasm .wasm

in a local .htaccess file and voila it works.
Thanks a lot to everybody who helped.

[Colton Idle]

awesome. TIL. what server are you using to host?

[Arjan van Wieringen]

.htaccess typically means Apache server

[Colton Idle]

gotcha. i guess i was curious which hosting provider. heroku, etc? idk. im not a web dev, so im just trying to learn where i can deploy my apps.

[Michael Paus]

Yes, it seems to be an Apache server. The hosting provider is https://www.ionos.de/