name : WithConditionalSheets.php <?php namespace Maatwebsite\Excel\Concerns; trait WithConditionalSheets { /** * @var array */ protected $conditionallySelectedSheets = []; /** * @param string|array $sheets * @return $this */ public function onlySheets($sheets) { $this->conditionallySelectedSheets = is_array($sheets) ? $sheets : func_get_args(); return $this; } /** * @return array */ public function sheets(): array { return \array_filter($this->conditionalSheets(), function ($name) { return \in_array($name, $this->conditionallySelectedSheets, false); }, ARRAY_FILTER_USE_KEY); } /** * @return array */ abstract public function conditionalSheets(): array; }