add DeliveryNoteReferencedDocument per Item

library/src/main/java/org/mustangproject/Item.java

@@ -46,6 +46,8 @@ public class Item implements IZUGFeRDExportableItem {
 	protected String parentLineID = null;
 	protected String lineStatusReasonCode = null;
  	protected TradeParty lineSeller;
+	protected String deliveryNoteReferencedDocumentID = null;
+	protected Date deliveryNoteReferencedDocumentDate = null;
 	//protected HashMap<String, String> attributes = new HashMap<>();
 
 	/***
@@ -187,6 +189,19 @@ public class Item implements IZUGFeRDExportableItem {
 				}
 			});
 
+		itemMap.getAsNodeMap("SpecifiedLineTradeDelivery").ifPresent(icnm -> {
+			icnm.getAsNodeMap("DeliveryNoteReferencedDocument").ifPresent(dn -> {
+				dn.getAsString("IssuerAssignedID")
+					.ifPresent(this::setDeliveryNoteReferencedDocumentID);
+
+				dn.getAsNodeMap("FormattedIssueDateTime")
+					.flatMap(fdt -> fdt.getNode("DateTimeString"))
+					.map(XMLTools::getNodeValue)
+					.map(XMLTools::tryDate)
+					.ifPresent(this::setDeliveryNoteReferencedDocumentDate);
+			});
+		});
+
 		itemMap.getAsNodeMap("SpecifiedLineTradeSettlement", "SpecifiedSupplyChainTradeSettlement").ifPresent(icnm -> {
 			icnm.getAsNodeMap("ApplicableTradeTax")
 				.flatMap(cnm -> cnm.getAsBigDecimal("RateApplicablePercent", "ApplicablePercent"))
@@ -697,4 +712,26 @@ public class Item implements IZUGFeRDExportableItem {
         return this.lineSeller;
     }
 
+	@Override
+	public String getDeliveryNoteReferencedDocumentID() {
+		return deliveryNoteReferencedDocumentID;
+	}
+
+
+	public Item setDeliveryNoteReferencedDocumentID(String deliveryNoteReferencedDocumentID) {
+		this.deliveryNoteReferencedDocumentID = deliveryNoteReferencedDocumentID;
+		return this;
+	}
+
+	@Override
+	public Date getDeliveryNoteReferencedDocumentDate() {
+		return deliveryNoteReferencedDocumentDate;
+	}
+
+
+	public Item setDeliveryNoteReferencedDocumentDate(Date deliveryNoteReferencedDocumentDate) {
+		this.deliveryNoteReferencedDocumentDate = deliveryNoteReferencedDocumentDate;
+		return this;
+	}
+
 }

library/src/main/java/org/mustangproject/ZUGFeRD/IZUGFeRDExportableItem.java

@@ -247,4 +247,24 @@ public interface IZUGFeRDExportableItem extends IAbsoluteValueProvider{
 		return null;
 	}
 
+	/**
+	 * get delivery note document ID (per Item - ZUGFeRD EXTENDED)
+	 * rsm:SupplyChainTradeTransaction/ram:IncludedSupplyChainTradeLineItem/ram:SpecifiedLineTradeDelivery/ram:DeliveryNoteReferencedDocument/IssuerAssignedID
+	 *
+	 * @return the ID of the delivery note document
+	 */
+	default String getDeliveryNoteReferencedDocumentID() {
+		return null;
+	}
+
+	/**
+	 * get delivery note document date (per Item - ZUGFeRD EXTENDED)
+	 * rsm:SupplyChainTradeTransaction/ram:IncludedSupplyChainTradeLineItem/ram:SpecifiedLineTradeDelivery/ram:DeliveryNoteReferencedDocument/FormattedIssueDateTime
+	 *
+	 * @return the date of the delivery note document
+	 */
+	default Date getDeliveryNoteReferencedDocumentDate() {
+		return null;
+	}
+
 }

library/src/main/java/org/mustangproject/ZUGFeRD/ZUGFeRD2PullProvider.java

@@ -534,8 +534,20 @@ public class ZUGFeRD2PullProvider implements IXMLProvider {
 				xml += "</ram:SpecifiedLineTradeAgreement>"
 					+ "<ram:SpecifiedLineTradeDelivery>"
 					+ "<ram:BilledQuantity unitCode=\"" + XMLTools.encodeXML(currentItem.getProduct().getUnit()) + "\">"
-					+ quantityFormat(currentItem.getQuantity()) + "</ram:BilledQuantity>"
+					+ quantityFormat(currentItem.getQuantity()) + "</ram:BilledQuantity>";
-					+ "</ram:SpecifiedLineTradeDelivery>"
+
+					if (currentItem.getDeliveryNoteReferencedDocumentID() != null && !currentItem.getDeliveryNoteReferencedDocumentID().trim().isEmpty()) {
+						xml += "<ram:DeliveryNoteReferencedDocument>";
+						xml += "<ram:IssuerAssignedID>" + XMLTools.encodeXML(currentItem.getDeliveryNoteReferencedDocumentID()) + "</ram:IssuerAssignedID>";
+						if (currentItem.getDeliveryNoteReferencedDocumentDate() != null) {
+							final SimpleDateFormat dateFormat102 = new SimpleDateFormat("yyyyMMdd");
+							xml += "<ram:FormattedIssueDateTime><qdt:DateTimeString format=\"102\">"+XMLTools.encodeXML(dateFormat102.format(currentItem.getDeliveryNoteReferencedDocumentDate()))+"</qdt:DateTimeString></ram:FormattedIssueDateTime>";
+						}
+						xml += "</ram:DeliveryNoteReferencedDocument>";
+
+					}
+
+					xml += "</ram:SpecifiedLineTradeDelivery>"
 					+ "<ram:SpecifiedLineTradeSettlement>"
 					+ "<ram:ApplicableTradeTax>"
 					+ "<ram:TypeCode>VAT</ram:TypeCode>";

library/src/main/java/org/mustangproject/ZUGFeRD/ZUGFeRDImporter.java

@@ -680,6 +680,7 @@ public class ZUGFeRDImporter extends ZUGFeRDInvoiceImporter {
 			for (int i = 0; i < nl.getLength(); i++) {
 				final Node nn = nl.item(i);
 				Node node = null;
+				Node subnode = null;
 				if (nn.getLocalName() != null) {
 					switch (nn.getLocalName()) {
 						case "SpecifiedLineTradeAgreement":
@@ -738,6 +739,24 @@ public class ZUGFeRDImporter extends ZUGFeRDInvoiceImporter {
 						case "SpecifiedSupplyChainTradeDelivery":
 							node = getNodeByName(nn.getChildNodes(), "BilledQuantity");
 							lineItem.setQuantity(XMLTools.tryBigDecimal(node));
+
+							node = getNodeByName(nn.getChildNodes(), "DeliveryNoteReferencedDocument");
+							if (node != null) {
+								subnode = getNodeByName(node.getChildNodes(), "IssuerAssignedID");
+								if (subnode != null) {
+									lineItem.setDeliveryNoteReferencedDocumentID(XMLTools.getNodeValue(subnode));
+								}
+								node = getNodeByName(node.getChildNodes(), "FormattedIssueDateTime");
+								if (node != null) {
+									NodeList FormattedIssueDateTimeChilds = node.getChildNodes();
+									for (int dateChildIndex = 0; dateChildIndex < FormattedIssueDateTimeChilds.getLength(); dateChildIndex++) {
+										if ((FormattedIssueDateTimeChilds.item(dateChildIndex).getLocalName() != null)
+											&& (FormattedIssueDateTimeChilds.item(dateChildIndex).getLocalName().equals("DateTimeString"))) {
+											lineItem.setDeliveryNoteReferencedDocumentDate(XMLTools.tryDate(FormattedIssueDateTimeChilds.item(dateChildIndex)));
+										}
+									}
+								}
+							}
 							break;
 
 						case "SpecifiedLineTradeSettlement":

library/src/test/java/org/mustangproject/ZUGFeRD/MustangReaderWriterCustomXMLTest.java

@@ -28,6 +28,8 @@ import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.nio.charset.StandardCharsets;
+import java.text.ParseException;
+import java.text.SimpleDateFormat;
 
 @FixMethodOrder(MethodSorters.NAME_ASCENDING)
 public class MustangReaderWriterCustomXMLTest extends TestCase {
@@ -100,6 +102,12 @@ public class MustangReaderWriterCustomXMLTest extends TestCase {
 					"</ram:SpecifiedLineTradeAgreement>\n" +
 					"<ram:SpecifiedLineTradeDelivery>\n" +
 					"<ram:BilledQuantity unitCode=\"HUR\">1.0000</ram:BilledQuantity>\n" +
+					"<ram:DeliveryNoteReferencedDocument>\n" +
+					"<ram:IssuerAssignedID>deliverynote123</ram:IssuerAssignedID>\n" +
+					"<ram:FormattedIssueDateTime>\n" +
+					"<udt:DateTimeString format=\"102\">20260114</udt:DateTimeString>\n" +
+					"</ram:FormattedIssueDateTime>\n" +
+					"</ram:DeliveryNoteReferencedDocument>\n" +
 					"</ram:SpecifiedLineTradeDelivery>\n" +
 					"<ram:SpecifiedLineTradeSettlement>\n" +
 					"<ram:ApplicableTradeTax>\n" +
@@ -279,6 +287,12 @@ public class MustangReaderWriterCustomXMLTest extends TestCase {
 		assertEquals(zi.getIBAN(), "DE88 2008 0000 0970 3757 00");
 		assertEquals(zi.getHolder(), "Bei Spiel GmbH");
 		assertEquals(zi.getForeignReference(), "RE-20171118/506");
+		assertEquals(zi.getLineItemList().get(0).getDeliveryNoteReferencedDocumentID(), "deliverynote123");
+		try {
+			assertEquals(zi.getLineItemList().get(0).getDeliveryNoteReferencedDocumentDate(), new SimpleDateFormat("dd.MM.yyyy").parse("14.01.2026"));
+		} catch (ParseException e) {
+			e.printStackTrace();
+		}
 	}
 
 	/**

library/src/test/java/org/mustangproject/ZUGFeRD/ZF2PushTest.java

@@ -611,7 +611,11 @@ public class ZF2PushTest extends TestCase {
 					.setInvoicer( new TradeParty("Abweichender Rechnungssteller", "Teststr.12", "04711", "Entenhausen", "DE") )
 					.setInvoicee( new TradeParty("Abweichender Rechnungsempfänger", "Teststr.42", "00815", "Entenhausen", "DE") )
 					.addItem(new Item(new Product("Testprodukt", "", "H87", new BigDecimal(16)).addGlobalID(gtin).setSellerAssignedID("4711"), price, new BigDecimal(1.0)).setId("a123").
-						addAdditionalReference(dr2).addBuyerOrderReferencedDocumentID("orderId").addBuyerOrderReferencedDocumentLineID("xxx").addReferencedLineID("xxx").addNote("item level 1/1").addAllowance(new Allowance(new BigDecimal(0.02)).setReason("item discount").setTaxPercent(new BigDecimal(16))).setDetailedDeliveryPeriod(sdf.parse("2020-01-13"), sdf.parse("2020-01-15")))
+						addAdditionalReference(dr2).addBuyerOrderReferencedDocumentID("orderId").addBuyerOrderReferencedDocumentLineID("xxx").addReferencedLineID("xxx")
+						.addNote("item level 1/1").addAllowance(new Allowance(new BigDecimal(0.02)).setReason("item discount").setTaxPercent(new BigDecimal(16))).setDetailedDeliveryPeriod(sdf.parse("2020-01-13"), sdf.parse("2020-01-15"))
+						.setDeliveryNoteReferencedDocumentID("deliverynote123")
+						.setDeliveryNoteReferencedDocumentDate(new SimpleDateFormat("dd.MM.yyyy").parse("14.01.2026"))
+					)
 					.addCharge(new Charge(new BigDecimal(0.5)).setReason("quick delivery charge").setTaxPercent(new BigDecimal(16)))
 					.addAllowance(new Allowance(new BigDecimal(0.2)).setReason("discount").setTaxPercent(new BigDecimal(16)))
 					.addCashDiscount(new CashDiscount(new BigDecimal(2), 14))
@@ -647,6 +651,12 @@ public class ZF2PushTest extends TestCase {
 		assertTrue(zi.getUTF8().contains(occurrenceTo));
 		assertTrue(zi.getUTF8().contains(contractID));
 		assertEquals(zi.importedInvoice.getZFItems()[0].getId(), "a123");
+		assertEquals(zi.importedInvoice.getZFItems()[0].getDeliveryNoteReferencedDocumentID(), "deliverynote123");
+		try {
+			assertEquals(zi.importedInvoice.getZFItems()[0].getDeliveryNoteReferencedDocumentDate(), new SimpleDateFormat("dd.MM.yyyy").parse("14.01.2026"));
+		} catch (ParseException e) {
+			e.printStackTrace();
+		}
 		assertTrue(zi.getUTF8().contains("20200113")); // to contain item delivery periods
 		assertTrue(zi.getUTF8().contains("20200115")); // to contain item delivery periods