Filament export action with a custom exporter

<?php

namespace App\Filament\Exports;

use App\Models\Candidate;
use Filament\Actions\Exports\Enums\ExportFormat;
use Filament\Actions\Exports\ExportColumn;
use Filament\Actions\Exports\Exporter;
use Filament\Actions\Exports\Models\Export;
use Illuminate\Database\Eloquent\Builder;
use Illuminate\Support\Number;

class CandidateExporter extends Exporter
{
    protected static ?string $model = Candidate::class;

    public static function getColumns(): array
    {
        return [
            ExportColumn::make('id')->label('ID'),
            ExportColumn::make('name'),
            ExportColumn::make('job.title')->label('Job'),
            ExportColumn::make('stage.name')->label('Stage'),
            ExportColumn::make('rating')
                ->formatStateUsing(fn (?int $state): string => $state === null ? '' : "$state / 5"),
            ExportColumn::make('expected_salary')
                ->formatStateUsing(fn (?int $state): string => $state === null ? '' : Number::format($state / 100, 2)),
            ExportColumn::make('tags_list')
                ->label('Tags')
                ->state(fn (Candidate $record): string => $record->tags->pluck('name')->implode('; ')),
            ExportColumn::make('applied_at')
                ->formatStateUsing(fn ($state): string => $state?->format('Y-m-d') ?? ''),
        ];
    }

    // CSV only: skip the XLSX option and its extra dependency.
    public function getFormats(): array
    {
        return [ExportFormat::Csv];
    }

    // Avoid N+1 queries while the exporter walks the rows.
    public static function modifyQuery(Builder $query): Builder
    {
        return $query->with(['job', 'stage', 'tags']);
    }

    public static function getCompletedNotificationBody(Export $export): string
    {
        $body = 'Your candidate export is ready: '.Number::format($export->successful_rows).' rows.';

        if ($failed = $export->getFailedRowsCount()) {
            $body .= ' '.Number::format($failed).' rows failed.';
        }

        return $body;
    }
}

<?php

namespace App\Filament\Resources\Candidates\Pages;

use App\Filament\Exports\CandidateExporter;
use App\Filament\Resources\Candidates\CandidateResource;
use Filament\Actions\ExportAction;
use Filament\Actions\ExportBulkAction;
use Filament\Resources\Pages\ListRecords;

class ListCandidates extends ListRecords
{
    protected static string $resource = CandidateResource::class;

    protected function getHeaderActions(): array
    {
        return [
            // Exports everything the current table query matches, filters included.
            ExportAction::make()
                ->exporter(CandidateExporter::class)
                ->label('Export all')
                ->fileName(fn () => 'candidates-'.now()->format('Ymd-His')),
        ];
    }
}

// In the resource's table(), selected rows can be exported too:
//
//     ->toolbarActions([
//         BulkActionGroup::make([
//             ExportBulkAction::make()->exporter(CandidateExporter::class),
//         ]),
//     ])