New samples demonstrating GetThirdPartyInvoice

- Fixes #757.

sample/invoice/GetThirdPartyInvoice.php

@@ -0,0 +1,38 @@
+<?php
+
+// # Get Third Invoice Sample
+// This sample code demonstrate how you can retrieve
+// a third party invoice.
+
+/** @var Invoice $invoice */
+$invoice = require 'CreateThirdPartyInvoice.php';
+use PayPal\Api\Invoice;
+
+$invoiceId = $invoice->getId();
+
+// Step 1. This would be refresh token retrieved from http://paypal.github.io/PayPal-PHP-SDK/sample/doc/lipp/ObtainUserConsent.html
+$refreshToken = "SCNWVZfdg43XaOmoEicazpkXyda32CGnP208EkuQ_QBIrXCYMhlvORFHHyoXPT0VbEMIHYVJEm0gVf1Vf72YgJzPScBenKoVPq__y1QRT7wwJo3WYADwUW4Q5ic";
+
+try {
+    // ### Step 2
+    // Update your apiContext with refresh token obtained from Step 1.
+    $apiContext->getCredential()->updateAccessToken($apiContext->getConfig(), $refreshToken);
+
+    // ### Retrieve Invoice
+    // Retrieve the invoice object by calling the
+    // static `get` method
+    // on the Invoice class by passing a valid
+    // Invoice ID
+    // (See bootstrap.php for more on `ApiContext`)
+    // Similar calls can be done to search invoices, delete, and update.
+    $retrievedInvoice = Invoice::get($invoiceId, $apiContext);
+
+    // NOTE: PLEASE DO NOT USE RESULTPRINTER CLASS IN YOUR ORIGINAL CODE. FOR SAMPLE ONLY
+    ResultPrinter::printResult("Get Third Party Invoice", "Invoice", $retrievedInvoice->getId(), $invoiceId, $retrievedInvoice);
+} catch (Exception $ex) {
+    // NOTE: PLEASE DO NOT USE RESULTPRINTER CLASS IN YOUR ORIGINAL CODE. FOR SAMPLE ONLY
+    ResultPrinter::printError("Get Third Party Invoice", "Invoice", $invoiceId, $invoiceId, $ex);
+    exit(1);
+}
+
+return $retrievedInvoice;