public function hasDiscount()
    {
        return $this->invoice->subtotal > 0 &&
            $this->invoice->subtotal != $this->invoice->total &&
            ! is_null($this->invoice->discount);
    }
public function hasDiscount()
    {
        return $this->invoice->subtotal > 0 &&
            $this->invoice->subtotal != $this->invoice->total &&
            ! is_null($this->invoice->discount);
    }
public function hasDiscount ( ) { return $ this -> invoice -> subtotal > 0 && $ this -> invoice -> subtotal != $ this -> invoice -> total && ! is_null ( $ this -> invoice -> discount ) ; }
Determine if the invoice has a discount.

@return bool
Determine if the invoice has a discount .