Added project reference (BT-11)

- Updated Invoice class
- Updated UBL reader and writer
- Updated tests

> Closes #60

src/Invoice.php

@@ -255,6 +255,7 @@ class Invoice {
  protected $salesOrderReference = null;
  protected $tenderOrLotReference = null;
  protected $contractReference = null;
+ protected $projectReference = null;
  protected $paidAmount = 0;
  protected $roundingAmount = 0;
  protected $customVatAmount = null;
@@ -679,6 +680,26 @@ public function setContractReference(?string $contractReference): self {
  }
 
 
+ /**
+ * Get project reference
+ * @return string|null Project reference
+ */
+ public function getProjectReference(): ?string {
+ return $this->projectReference;
+ }
+
+
+ /**
+ * Set project reference
+ * @param string|null $contractReference Project reference
+ * @return self Invoice instance
+ */
+ public function setProjectReference(?string $projectReference): self {
+ $this->projectReference = $projectReference;
+ return $this;
+ }
+
+
  /**
  * Get invoice prepaid amount
  * @return float Invoice prepaid amount

src/Readers/UblReader.php

@@ -183,6 +183,12 @@ public function import(string $document): Invoice {
  $invoice->addAttachment($this->parseAttachmentNode($node));
  }
 
+ // BT-11: Project reference
+ $projectReferenceNode = $xml->get("{{$cac}}ProjectReference/{{$cbc}}ID");
+ if ($projectReferenceNode !== null) {
+ $invoice->setProjectReference($projectReferenceNode->asText());
+ }
+
  // Seller node
  $sellerNode = $xml->get("{{$cac}}AccountingSupplierParty/{{$cac}}Party");
  if ($sellerNode !== null) {

src/Writers/UblWriter.php

@@ -141,6 +141,12 @@ public function export(Invoice $invoice): string {
  $this->addTenderOrLotReferenceNode($xml, $invoice);
  }
 
+ // BT-11: Project reference
+ $projectReference = $invoice->getProjectReference();
+ if ($projectReference !== null) {
+ $xml->add('cac:ProjectReference')->add('cbc:ID', $projectReference);
+ }
+
  // Seller node
  $seller = $invoice->getSeller();
  if ($seller !== null) {

tests/Integration/peppol-base.xml

@@ -51,6 +51,9 @@
  <cbc:EmbeddedDocumentBinaryObject mimeCode="application/pdf" filename="ATT-1234.pdf">VGhlIGF0dGFjaG1lbnQgcmF3IGNvbnRlbnRz</cbc:EmbeddedDocumentBinaryObject> 
  </cac:Attachment>
  </cac:AdditionalDocumentReference>
+ <cac:ProjectReference>
+ <cbc:ID>PROJ-1234</cbc:ID>
+ </cac:ProjectReference>
  <cac:AccountingSupplierParty>
  <cac:Party>
  <cbc:EndpointID schemeID="0088">9482348239847239874</cbc:EndpointID>