belongsTo(Payment::class); } public function isPaid(): bool { return $this->status === 'paid'; } public function markPaid(Payment $payment): void { $this->update([ 'status' => 'paid', 'payment_id' => $payment->id, ]); } /** * 作为可购买实体(市场商品)的展示约定。 */ public function payableLabel(): string { return '市场商品:'.$this->title; } public function payableUrl(): ?string { return null; } }