Added example how to combine existing PDF and invoice XML

README.md

@@ -67,4 +67,16 @@ private fun createInvoice() = Invoice(
     recipient = Party("Abzock GmbH", "Ausbeutstr.", "12345", "Abzockhausen"),
     items = listOf(LineItem("Erbrachte Dienstleistungen", "HUR", BigDecimal(170), BigDecimal(1_000_000), BigDecimal(19))) // HUR = EN code for hour
 )
+```
+
+### Attach invoice XML to existing PDF
+
+```kotlin
+val invoice: Invoice = createInvoice()
+val existingPdf = File("Invoice.pdf")
+val output = File("Zugferd.pdf")
+
+val creator = EInvoiceCreator()
+
+creator.combinePdfAndInvoiceXml(invoice, existingPdf, output)
 ```

e-invoicing-domain/src/main/kotlin/net/codinux/invoicing/creation/EInvoiceCreator.kt

@@ -32,13 +32,16 @@ class EInvoiceCreator(
         val visualizer = ZUGFeRDVisualizer()
         visualizer.toPDF(xmlFile.absolutePath, pdfFile.absolutePath)
 
-        combinePdfAndXml(pdfFile, xml, outputFile)
+        combinePdfAndInvoiceXml(xml, pdfFile, outputFile)
 
         xmlFile.delete()
         pdfFile.delete()
     }
 
-    fun combinePdfAndXml(pdfFile: File, xml: String, outputFile: File) {
+    fun combinePdfAndInvoiceXml(invoice: Invoice, pdfFile: File, outputFile: File) =
+        combinePdfAndInvoiceXml(createZugferdXml(invoice), pdfFile, outputFile)
+
+    fun combinePdfAndInvoiceXml(invoiceXml: String, pdfFile: File, outputFile: File) {
         val exporter = ZUGFeRDExporterFromA3()
             .setZUGFeRDVersion(2)
             .setProfile("EN16931") // available values: MINIMUM, BASICWL, BASIC, CIUS, EN16931, EXTENDED, XRECHNUNG
@@ -47,7 +50,7 @@ class EInvoiceCreator(
             .setCreator(System.getProperty("user.name"))
 
         exporter.load(pdfFile.inputStream())
-        exporter.setXML(xml.toByteArray())
+        exporter.setXML(invoiceXml.toByteArray())
 
         exporter.export(outputFile.outputStream())
     }

e-invoicing-domain/src/test/kotlin/net/codinux/invoicing/Demonstration.kt

@@ -62,6 +62,17 @@ class Demonstration {
         val xRechnung = creator.createXRechnungXml(invoice)
     }
 
+    fun combinePdfAndInvoiceXml() {
+        val invoice: Invoice = createInvoice()
+        val existingPdf = File("Invoice.pdf")
+        val output = File("Zugferd.pdf")
+
+        val creator = EInvoiceCreator()
+
+        creator.combinePdfAndInvoiceXml(invoice, existingPdf, output)
+    }
+
+
     private fun createInvoice() = Invoice(
         invoiceNumber = "RE-00001",
         invoicingDate = LocalDate.now(),