Empty or null ChildRowContent of MudDataGrid cause visual bug

[XPhilipp]

Bug type

Component

Component name

MudDataGrid

What happened?

If you programmatically define "Row Detail View", then an empty ChildRowContent leads to a visual bug - empty lines between the grid lines

Expected behavior

Normal representation without extra blank lines

Reproduction link

https://try.mudblazor.com/snippet/cEGRvakRBFncGGKm

Reproduction steps

1. Run Snippet

Relevant log output

No response

Version (bug)

6.10.0

Version (working)

No response

What browsers are you seeing the problem on?

Chrome

On what operating system are you experiencing the issue?

Windows

Pull Request

• [ ] I would like to do a Pull Request

Code of Conduct

• [X] I agree to follow this project's Code of Conduct

[CircuitSage]

Hopefully this one gets some attention. I don't have time right now to investigate a proper solution or workaround, but it looks like it may be related to these areas of MudDataGrid: `@if (ChildRowContent != null && (_openHierarchies.Contains(item) || !hasHierarchyColumn)) {

@ChildRowContent(new CellContext(this, item))

}`

Where ChildRowContent is never null when you've added it to your data grid, even if you don't pass anything into it. The RenderFragment is still instantiated, even without content. In my situation, shared below, even when the if statement is false here, the row is rendered as an empty row.

`@if (context.Item.IsExpanded && context.Item.DynamicComponentType != null) {

}`

If someone has a workaround to this, please let me know.

[ScarletKuro]

Hi. The thing is that in Blazor there is no API to know if the RenderFragment has an empty content or that it's currently not rending it's content because of the condition That's why when you declare the ChildRowContent the RenderFragment is not null anymore. And this part is getting invoked https://github.com/MudBlazor/MudBlazor/blob/0824b2135c504fcd74798acca6b53c429b4fbb14/src/MudBlazor/Components/DataGrid/MudDataGrid.razor#L251-L258 The applied mud-table-cell style is what causing this "empty" line to show up. I think the main idea behind ChildRowContent was that you either have always some content, or you have like a toggle button inside that will hide/show content.

[ScarletKuro]

As workaround you could do something like this: https://try.mudblazor.com/snippet/cEQeEnFQywritWmt Usually, I strongly don't recommend doing this in Blazor, but I don't have anything else to offer.

Also, this is not really correct:

    @if (!_isReadOnly)
    {
        <HierarchyColumn T="Element" ButtonDisabledFunc="@(x => x.Sign == "He")" />
    }

As every time this changes _isReadOnly you will add a new reference to the RenderColumns and in will duplicate, please read this: https://github.com/MudBlazor/MudBlazor/issues/6569#issuecomment-1493373386.

[LoganAnde]

Here's a small workaround I've come up with. https://try.mudblazor.com/snippet/QawSkycHrvmLqJfT

Only catch is that the :has() pseudo-class is only standard in browsers as of December 2023, so if you can't guarantee that your users have up-to-date browsers I imagine you could easily do something similar using JS interop.