Add getPagination* concrete functions on Pagination trait (#271)

src/Mailgun/Api/Pagination.php

@@ -10,6 +10,7 @@
 namespace Mailgun\Api;
 
 use Mailgun\Assert;
+use Mailgun\Resource\Api\PagingProvider;
 use Psr\Http\Message\ResponseInterface;
 
 /**
@@ -21,13 +22,53 @@ trait Pagination
 
     abstract protected function safeDeserialize(ResponseInterface $response, $className);
 
+    /**
+     * @param PagingProvider $response
+     *
+     * @return PagingProvider|null
+     */
+    public function nextPage(PagingProvider $response)
+    {
+        return $this->getPaginationUrl($response->getNextUrl(), get_class($response));
+    }
+
+    /**
+     * @param PagingProvider $response
+     *
+     * @return PagingProvider|null
+     */
+    public function previousPage(PagingProvider $response)
+    {
+        return $this->getPaginationUrl($response->getPreviousUrl(), get_class($response));
+    }
+
+    /**
+     * @param PagingProvider $response
+     *
+     * @return PagingProvider|null
+     */
+    public function firstPage(PagingProvider $response)
+    {
+        return $this->getPaginationUrl($response->getFirstUrl(), get_class($response));
+    }
+
+    /**
+     * @param PagingProvider $response
+     *
+     * @return PagingProvider|null
+     */
+    public function lastPage(PagingProvider $response)
+    {
+        return $this->getPaginationUrl($response->getLastUrl(), get_class($response));
+    }
+
     /**
      * @param string $url
      * @param string $class
      *
-     * @return mixed|null
+     * @return PagingProvider|null
      */
-    public function getPaginationUrl($url, $class)
+    private function getPaginationUrl($url, $class)
     {
         Assert::stringNotEmpty($class);
 

src/Mailgun/Resource/Api/Event/EventResponse.php

@@ -9,13 +9,14 @@
 
 namespace Mailgun\Resource\Api\Event;
 
+use Mailgun\Resource\Api\PagingProvider;
 use Mailgun\Resource\Api\PaginationResponse;
 use Mailgun\Resource\ApiResponse;
 
 /**
  * @author Tobias Nyholm <tobias.nyholm@gmail.com>
  */
-class EventResponse implements ApiResponse
+class EventResponse implements ApiResponse, PagingProvider
 {
     use PaginationResponse;
 

src/Mailgun/Resource/Api/PagingProvider.php

@@ -0,0 +1,44 @@
+<?php
+
+/*
+ * Copyright (C) 2013-2016 Mailgun
+ *
+ * This software may be modified and distributed under the terms
+ * of the MIT license. See the LICENSE file for details.
+ */
+
+namespace Mailgun\Resource\Api;
+
+/**
+ * @author Sean Johnson <sean@mailgun.com>
+ */
+interface PagingProvider
+{
+    /**
+     * Returns the `$paging->next` URL.
+     *
+     * @return string
+     */
+    public function getNextUrl();
+
+    /**
+     * Returns the `$paging->prev` URL.
+     *
+     * @return string
+     */
+    public function getPreviousUrl();
+
+    /**
+     * Returns the `$paging->first` URL.
+     *
+     * @return string
+     */
+    public function getFirstUrl();
+
+    /**
+     * Returns the `$paging->last` URL.
+     *
+     * @return string
+     */
+    public function getLastUrl();
+}