Open the diagram on a table

A resource can offer a button that opens the diagram with its own table already focused. Truss reads focus from the query string and applies it on load, so the whole feature is a URL:

/admin/database-schema?focus=books

Nothing of the plugin’s runs in the browser for this. There is no JavaScript to publish, no asset to build and nothing added to the payload. It is also why the feature cannot drift: the parameter is Truss’s, and the plugin only writes it.

Opting a resource in

The trait is the short way, and it works because every Filament resource can answer getModel():

use AlbertoArena\FilamentTruss\Actions\Concerns\HasViewInSchemaAction;
use Filament\Resources\Resource;

class BookResource extends Resource
{
    use HasViewInSchemaAction;

    // ...
}

Then put the action wherever the panel wants it. In a page header, beside Create:

use App\Filament\Resources\Books\BookResource;
use Filament\Actions\CreateAction;
use Filament\Resources\Pages\ListRecords;

class ListBooks extends ListRecords
{
    protected static string $resource = BookResource::class;

    protected function getHeaderActions(): array
    {
        return [
            BookResource::viewInSchemaAction(),
            CreateAction::make(),
        ];
    }
}

Put the trait on a base resource class and every resource extending it is opted in, which is why it is a trait rather than a copied closure.

Without the trait

ViewInSchemaAction is an ordinary Filament\Actions\Action, so it goes anywhere an action goes: a page header, a table row action, an action group.

use AlbertoArena\FilamentTruss\Actions\ViewInSchemaAction;

ViewInSchemaAction::make()->forModel(Book::class);
ViewInSchemaAction::make()->forTable('books');

Being an ordinary action, it takes the ordinary methods too: ->label(), ->icon(), ->color(), ->link(), ->button(). The defaults are View in schema, a grey outlined circle-stack icon, and the panel’s own styling.

It is per table, not per record

Focus narrows the diagram to a table and its neighbours, so every row of Books points at the same place. A row action is a legitimate placement, it just does not focus “this book”.

When the button is not there

It removes itself rather than greying out, in three cases. In each one there is nothing the viewer could do about it, and a disabled control invites them to try.

Case	Why
The panel has no schema page	A resource registered on two panels where only one has the plugin. Building the URL would otherwise throw.
The viewer may not see the page	The page’s own rule, which is Truss’s rule. Being allowed to list Books is not being allowed to read the database structure.
Truss excludes the table	?focus= naming an excluded table matches no drawn table and is ignored, so the button would land on an unfocused diagram and read as broken.

Worth knowing

• The focused URL is an address. It bookmarks, it shares and it survives a reload, because the state is in the query string rather than in the page.
• Depth is Truss’s, from truss.focus.default_depth. The link does not set it, and the plugin adds no way to set it per button.

See Focus and filter for what focus does to the diagram.