Conditional rendering in header-cell causes empty cells

[danielwillms]

What happened?

I wanted to use the header-cell Slot on the QTable to render different QTh Elements, depending on a condition.
Unfortunately this wasn't working, the first Element with v-if will be rendered, if the condition is true.
All other elements, whether with v-else-if or v-else condition, won't get rendered.
Wrapping it in a template causes it to render nothing at all.
I found the issue #9185 where there was an almost identical problem in the body-cell slot, maybe you can apply the same fix to it?

What did you expect to happen?

Different QTh Elements to be rendered to their specific condition

Reproduction URL

https://codepen.io/3m7ecc/pen/MWXvxVR

How to reproduce?

1. Go to the provided reproduction link
2. See on Table#1 only Headers being rendered with sortable: true
3. See on Table#2 no headers being rendered at all

Flavour

Quasar CLI with Vite (@quasar/cli | @quasar/app-vite)

Areas

Components (quasar)

Platforms/Browsers

Firefox, Chrome

Quasar info output

No response

Relevant log output

No response

Additional context

No response

[metalsadman]

https://codepen.io/metalsadman/pen/YzvrWgV

[danielwillms]

https://codepen.io/metalsadman/pen/YzvrWgV

Yes, of course it will work when you put the condition inside the QTh, but in my case I have multiple components which use QTh as the root component and want to switch between those, depending on a flag set in the columns!

And either way, shouldn't it still be possible to use these conditions inside header-cell, if it's possible to use it in body-cell?

[metalsadman]

https://codepen.io/metalsadman/pen/YzvrWgV

Yes, of course it will work when you put the condition inside the QTh, but in my case I have multiple components which use QTh as the root component and want to switch between those, depending on a flag set in the columns!

And either way, shouldn't it still be possible to use these conditions inside header-cell, if it's possible to use it in body-cell?

do it like you're doing, but use a key ie. <q-td :key="props.col.name"..., you have a questionable condition too, where some columns you didn't define sortable or defined it as string so you'll have to account for that also.
https://codepen.io/metalsadman/pen/poKWEpv

[danielwillms]

The key seems to be the problem.
Now it's working, thank you very much.

The sortable thing was just for the example, in my case I extend the columns-definition with my own attributes and then decide based on the value.