Dynamic properties mimetype fix

[thetableman]

This PR aims to resolve the Failed to load module script: Expected a JavaScript module script but the server responded with a MIME type of "text/plain". error with elements using dynamic_properties.js, examples of this error are noted in #1510 and #1579.

Credit to @natankeddem for finding and suggesting the fix in #1579.

[thetableman]

Tested the additional mimetype in __init__.py of the main nicegui directory and in ui.py however the issue persisted. Applying to element.py resolved the issue for me for both echart and aggrid elements.

Given this error seems to affect only certain systems additional testers would be welcome.

[natankeddem]

If you can take a quick look in regedit, could you double check this is what you are seeing?

Windows Registry Editor Version 5.00

[HKEY_CLASSES_ROOT\.js]
"Content Type"="text/plain"

If so I can "break" my PC similarly to test this out. Are you running directly in Windows 10 or using WSL?

[thetableman]

I have the issue when using Win 11 directly (no WSL). Confirming that "Content Type"="text/plain" for .js.

[rodja]

This is originally a Windows/Starlette issue which other projects also have build workarounds for: encode/starlette#829

[falkoschindler]

Thanks for this PR, @thetableman!

I have two questions:

1. Can we move the lines into nicegui.py close to static_files = StaticFiles(...). I think this is the place that actually requires the fix.
2. I think the correct mime type for JavaScript would be "text/javascript" (see https://stackoverflow.com/a/21098951/3419103). Or am I missing something?

[natankeddem]

2. I think the correct mime type for JavaScript would be "text/javascript" (see https://stackoverflow.com/a/21098951/3419103). Or am I missing something?

That link states "text/javascript" is obsolete.

[natankeddem]

Nevermind, it might not be. This RFC confused me https://tools.ietf.org/html/rfc4329

[falkoschindler]

I just moved the fix to nicegui.py and added a pytest.
@thetableman, @natankeddem, can you confirm that it still works on your machines?

[natankeddem]

I was never able to "break" a fresh windows 10 install. I tried adding the key/value to 2 locations per the reports I saw. Perhaps there is more to change but unless @thetableman can't verify i'll pass on digging in further on that.

New-PSDrive -Name HKLM -PSProvider Registry -Root HKEY_LOCAL_MACHINE
New-PSDrive -Name HKCR -PSProvider Registry -Root HKEY_CLASSES_ROOT
Set-Itemproperty -path 'HKLM:\SOFTWARE\Classes\.js' -Name 'Content Type' -value 'text/plain'
Set-Itemproperty -path 'HKCR:\.js' -Name 'Content Type' -value 'text/plain'

[thetableman]

I just moved the fix to nicegui.py and added a pytest. @thetableman, @natankeddem, can you confirm that it still works on your machines?

Moving mimetypes to nicegui.py also resolves the issue on my Win10 installation. I also tested with both application/javascript and text/javascript, both fixed the error I was receiving.

There's a lot of conflicting information about which to use but Mozilla, which nicegui references in other places as a primary source, reads here https://developer.mozilla.org/en-US/docs/Web/HTTP/Basics_of_HTTP/MIME_types#textjavascript that text/javascript is the current standard. This makes sense as application/... suggests a binary file type, which of course javascript is not.

[falkoschindler]

Great, thanks @thetableman!
Then let's close this one by merging into main. 🚀