[4.x] fix - handle Htmlable state in TextEntry/TextColumn toEmbeddedHtml blank check

[SimonBroekaert]

Description

When rendering the content of a Filament\Forms\Components\RichEditor field using a Filament\Infolists\Components\TextEntry when the model is set up with the Filament\Forms\Components\RichEditor\Models\Contracts\HasRichContent contract and Filament\Forms\Components\RichEditor\Models\Concerns\InteractsWithRichContent trait, the placeholder is never rendered.

This is because the blank($state) check does return false because it is given a Filament\Forms\Components\RichEditor\RichContentAttribute.

This fix checks if the $state implements Illuminate\Contracts\Support\Htmlable and uses the rendered html in the blank check instead.

This fixes both NULL and EMPTY values.

Functional changes

• Code style has been fixed by running the composer cs command.
• Changes have been tested to not break existing functionality.
• Documentation is up-to-date.

[danharrin]

Does the same need to happen for TextColumn?

[SimonBroekaert]

Does the same need to happen for TextColumn?

Ah yes, the TextColumn can indeed also render the RichContentAttribute. I've tested it on my project and indeed, the placeholder is not rendering there either.

I've updated the PR to also add the change to that blank check.

Thanks! 🙏