Default values don't seem to be displayed when using themes

[benjdlambert]

Prerequisites

• I have searched the existing issues
• I understand that providing a SSCCE example is tremendously useful to the maintainers.
• I have read the documentation
• Ideally, I'm providing a sample JSFiddle, Codesandbox.io or preferably a shared playground link demonstrating the issue.

What theme are you using?

material-ui

Version

5.x

Current Behavior

It looks like there's some issues with default values not being displayed properly when using some themes. The default theme and bootstrap themes work as expected, but it looks like the material-ui / mui themes don't render the default value correctly.

Expected Behavior

The default value renders in the input field

Steps To Reproduce

material-ui playground link

default theme playground link

Environment

Not relevant

Anything else?

Apologies if there's already an issue for this already, but don't think it's related to the already existing allOf if-then-else issues as this seems to be a theme issue rather than a core library problem?

[heath-freenome]

@benjdlambert Wow, this seems to be an issue with the SelectWidget implementation in the non-bootstrap themes. Thanks for finding it. Are you willing to debug the material-ui issue and let us know what you find? I'm guessing the bug is probably consistent across all themes?

[benjdlambert]

@heath-freenome i can for sure dig around a little bit. Thanks for pointing in a direction on where to start!

And yep, seems the data is in the model but not rendered in the widget. I only tested both material and mui but I'm guessing there's other themes with this issue the fix is similar.

Will test with the other themes too.

[benjdlambert]

@heath-freenome did some digging around, and it actually looks like this is just a symptom of #3892. The values are never added to the model, so what happens is that some of the themes have a placeholder for the first item in the list.

I will close this issue as a duplicate, and look at implementing that.