add AbstractService method: getResponsePaginationLinks

src/Object/PaginationLink.php

@@ -0,0 +1,23 @@
+<?php
+
+namespace Shopify\Object;
+
+class PaginationLink
+{
+    public $previous;
+
+    public $next;
+
+    public function __construct(string $linkHeader)
+    {
+        if (empty($linkHeader)) {
+            return;
+        }
+
+        foreach (explode(',', $linkHeader) as $item) {
+            if (preg_match('/<([\s\S]+?)>; rel=\"(next|previous)\"/', $item, $match)) {
+                $this->{$match[2]} = $match[1];
+            }
+        }
+    }
+}

src/Service/AbstractService.php

@@ -6,6 +6,7 @@
 use GuzzleHttp\Psr7\Request;
 use GuzzleHttp\Psr7\Response;
 use Shopify\ApiInterface;
+use Shopify\Object\PaginationLink;
 
 abstract class AbstractService
 {
@@ -106,4 +107,13 @@ function ($object) use ($className) {
             }, $data
         );
     }
+
+    /** [fetch pagination link from Shopify Link headers]
+     *  supported only in api version 2019-07 of the API and above
+     * @return PaginationLink
+     */
+    public function getPaginationLink(): PaginationLink
+    {
+        return new PaginationLink($this->getLastResponse()->getHeaderLine('Link'));
+    }
 }

test/Service/PaginationLinkTest.php

@@ -0,0 +1,41 @@
+<?php
+
+namespace Shopify\Test\Service;
+
+use Shopify\Object\PaginationLink;
+use Shopify\Service\CustomerService;
+use Shopify\Test\TestCase;
+
+class PaginationLinkTest extends TestCase
+{
+    public function testGetPaginationLink()
+    {
+        $previous = 'https://demo.myshopify.com/admin/api/2021-01/customers.json?limit=5&page_info=xyzprevious';
+        $next = 'https://demo.myshopify.com/admin/api/2021-01/customers.json?limit=5&page_info=xyznext';
+
+        // test previous && next
+        $api = $this->getApiMock(
+            ['customers' => ['unit test']],
+            ['Link' => '<' . $previous . '>; rel="previous", <' . $next . '>; rel="next"']
+        );
+
+        $service = new CustomerService($api);
+        $service->all();
+        $res = $service->getPaginationLink();
+        $this->assertInstanceOf(PaginationLink::class, $res);
+        $this->assertTrue($res->next == $next);
+        $this->assertTrue($res->previous == $previous);
+
+        // test only next
+        $api = $this->getApiMock(
+            ['customers' => ['unit test']],
+            ['Link' => '<' . $next . '>; rel="next"']
+        );
+
+        $service = new CustomerService($api);
+        $service->all();
+        $res = $service->getPaginationLink();
+        $this->assertInstanceOf(PaginationLink::class, $res);
+        $this->assertTrue($res->next == $next);
+    }
+}

test/TestCase.php

@@ -20,7 +20,7 @@ public function getApi(array $params = array())
         return $api;
     }
 
-    public function getApiMock($file)
+    public function getApiMock($file, array $headers = ['X-Foo' => 'Bar'])
     {
         $json = null;
         if (is_array($file)) {
@@ -33,7 +33,7 @@ public function getApiMock($file)
             }
             $json = file_get_contents($path);
         }
-        $mock = new MockHandler([new Response(200, ['X-Foo' => 'Bar'], $json)]);
+        $mock = new MockHandler([new Response(200, $headers, $json)]);
 
         $handler = HandlerStack::create($mock);
         $client = new Client(['handler' => $handler]);