Add CbpStrategy accepting OBP params

README.md

@@ -132,13 +132,31 @@ There are two ways to do pagination in the Zendesk API, **CBP (Cursor Based Pagi
 The use of the correct pagination is encapsulated using the iterator pattern, which allows you to retrieve all resources in all pages, without having to deal with pagination at all:
 
 ```php
-$ticketsIterator = $client->tickets()->iterator();
+$iterator = $client->tickets()->iterator();
 
-foreach ($ticketsIterator as $ticket) {
-    process($ticket); // Your implementation
+foreach ($iterator as $ticket) {
+    echo($ticket->id . " ");
 }
 ```
 
+If you want a specific sort order, please refer to the sorting section in the documentation ([Tickets, for example](https://developer.zendesk.com/api-reference/ticketing/tickets/tickets/#sorting)). If you are upgrading from OBP, please refer to [the upgrade guide](./UPGRADE_GUIDE.md).
+
+##### Iterator with params example
+
+```php
+$params = ['my' => 'param1', 'extra' => 'param2'];
+$iterator = $client->tickets()->iterator($params);
+
+foreach ($iterator as $ticket) {
+    echo($ticket->id . " ");
+}
+```
+
+* Change page size with: `$params = ['page[size]' => 5];`
+* Change sorting with: `$params = ['sort' => '-updated_at'];`
+  * Refer to the docs for details, including allowed sort fields
+* Combine everything: `$params = ['page[size]' => 2, 'sort' => 'updated_at', 'extra' => 'param'];`
+
 #### Find All using CBP (fine)
 
 If you still want use `findAll()`, until CBP becomes the default API response, you must explicitly request CBP responses by using the param `page[size]`.

UPGRADE_GUIDE.md

@@ -0,0 +1,90 @@
+# Upgrade guide
+
+## Useful links
+
+* [Pagination](https://developer.zendesk.com/api-reference/introduction/pagination)
+* [Ticketing sorting](https://developer.zendesk.com/api-reference/ticketing/tickets/tickets/#sorting)
+
+## CBP Basics
+
+**OBP (Offset Based Pagination)** is quite inefficient, and increasingly so the higher the page you fetch. Switching to **CBP (Cursor Based Pagination)** will improve your application performance. OBP will eventually be subject to limits.
+
+When using OBP, if you request page 100, the DB will need to index all records that proceed it before it can load the rows for the page you requested.
+
+CBP works based on cursors, so when ordering by `id` with page size 10, if the last item on your page has id 111, the response includes a link to the next page (`links.next`) which can be used to request the next 10 elements after id 111, and only the requested rows are indexed before fetching. When in the response `meta.has_more` is `false` you are done.
+
+## API calls
+
+URL example:
+
+* OBP: https://{subdomain}.zendesk.com/api/v2/tickets?sort_order=desc&sort_by=updated_at&per_page=2
+* CBP: https://{subdomain}.zendesk.com/api/v2/tickets?sort=-updated_at&page[size]=2
+
+### CBP ordering
+
+When moving from OBP to CBP sorting params change as well:
+
+* From: `?sort_name=updated_at&sort_order=desc`
+* To: `sort=-updated_at`
+
+Ticket example:
+
+* OBP: https://{subdomain}.zendesk.com/api/v2/tickets?sort_order=desc&sort_by=updated_at&per_page=2
+* CBP: https://{subdomain}.zendesk.com/api/v2/tickets?sort=-updated_at&page[size]=2
+
+However, the list of **attributes you can sort by might also change** with the pagination type:
+
+https://developer.zendesk.com/api-reference/ticketing/tickets/tickets/#sorting
+
+* OBP: `"assignee", "assignee.name", "created_at", "group", "id", "locale", "requester"`
+* CBP: `"updated_at", "id", "status"`
+
+Example:
+
+* OBP: https://{subdomain}.zendesk.com/api/v2/tickets?sort_order=desc&sort_by=assignee.name&per_page=2 `HTTP 200`, works
+* CBP: https://{subdomain}.zendesk.com/api/v2/tickets?sort=assignee.name&page[size]=2 `HTTP 400`
+
+```json
+{
+    "error": "InvalidPaginationParameter",
+    "description": "sort is not valid"
+}
+```
+
+If this is your situation, **you will need to change the sorting order** to a supported one.
+
+## The new iterator
+
+The most efficient and elegant way to implement CBP is to use the newly provided iterator on your resources, for example:
+
+```php
+$params = ['my' => 'param1', 'extra' => 'param2'];
+$iterator = $client->tickets()->iterator($params);
+
+foreach ($iterator as $ticket) {
+    echo($ticket->id . " ");
+}
+```
+
+This will choose the right type of pagination and adapt your parameters for pagination and ordering to work with CBP.
+
+##### Iterator with params example
+
+```php
+$params = ['my' => 'param1', 'extra' => 'param2'];
+$iterator = $client->tickets()->iterator($params);
+
+foreach ($iterator as $ticket) {
+    echo($ticket->id . " ");
+}
+```
+
+* Change page size with: `$params = ['page[size]' => 5];`
+* Change sorting with: `$params = ['sort' => '-updated_at'];`
+  * Refer to the docs for details, including allowed sort fields
+* Combine everything: `$params = ['page[size]' => 2, 'sort' => 'updated_at', 'extra' => 'param'];`
+
+
+## Parallel requests
+
+If you are fetching multiple pages in parallel using OBP, you need to refactor to a serial execution, and fetch one page at a time.

src/Zendesk/API/Traits/Resource/FindAll.php

@@ -3,7 +3,6 @@
 namespace Zendesk\API\Traits\Resource;
 
 use Zendesk\API\Exceptions\RouteException;
-use Zendesk\API\Traits\Utility\Pagination\CbpStrategy;
 
 trait FindAll
 {

src/Zendesk/API/Traits/Resource/Pagination.php

@@ -2,32 +2,32 @@
 
 namespace Zendesk\API\Traits\Resource;
 
-use Zendesk\API\Traits\Utility\Pagination\AbstractStrategy;
 use Zendesk\API\Traits\Utility\Pagination\CbpStrategy;
 use Zendesk\API\Traits\Utility\Pagination\PaginationIterator;
 
 trait Pagination {
     /**
      * Usage:
+     * $ticketsIterator = $client->tickets()->iterator();
      * foreach ($ticketsIterator as $ticket) {
-     *     process($ticket)
+     *     process($ticket);
      * }
      *
      * @return PaginationIterator to fetch all pages.
      */
     public function iterator($params = [])
     {
         $strategyClass = $this->paginationStrategyClass();
-        $strategy = new $strategyClass($this->resourcesKey(), AbstractStrategy::DEFAULT_PAGE_SIZE);
-        return new PaginationIterator($this, $strategy, $params);
+        $strategy = new $strategyClass($this->resourcesKey(), $params);
+
+        return new PaginationIterator($this, $strategy);
     }
 
     /**
      * Override this method in your resources
      *
      * @return string subclass of AbstractStrategy used for fetching pages
      */
-
     protected function paginationStrategyClass() {
         return CbpStrategy::class;
     }

src/Zendesk/API/Traits/Utility/Pagination/AbstractStrategy.php

@@ -3,20 +3,39 @@
 
 abstract class AbstractStrategy
 {
-    public const DEFAULT_PAGE_SIZE = 100;
-
     /**
      * @var string The response key where the data is returned
      */
     protected $resourcesKey;
+    protected $params;
     protected $pageSize;
 
-    public function __construct($resourcesKey, $pageSize = self::DEFAULT_PAGE_SIZE)
+    public function __construct($resourcesKey, $params)
     {
         $this->resourcesKey = $resourcesKey;
-        $this->pageSize = $pageSize;
+        $this->params = $params;
+    }
+
+    public function params()
+    {
+        return $this->params;
+    }
+
+    protected function pageSize()
+    {
+        if (isset($this->pageSize)) {
+            return $this->pageSize;
+        } else if (isset($this->params['page[size]'])) {
+            $this->pageSize = $this->params['page[size]'];
+        } else if (isset($this->params['per_page'])) {
+            $this->pageSize = $this->params['per_page'];
+        } else {
+            $this->pageSize = DEFAULT_PAGE_SIZE;
+        }
+
+        return $this->pageSize;
     }
 
-    abstract public function getPage($pageFn);
+    abstract public function page($getPageFn);
     abstract public function shouldGetPage($position);
 }

src/Zendesk/API/Traits/Utility/Pagination/CbpStrategy.php

@@ -11,20 +11,65 @@ class CbpStrategy extends AbstractStrategy
     private $afterCursor = null;
     private $started = false;
 
-    public function getPage($pageFn)
+    public function page($getPageFn)
     {
         $this->started = true;
-        $params = ['page[size]' => $this->pageSize];
-        if ($this->afterCursor) {
-            $params['page[after]'] = $this->afterCursor;
-        }
-        $response = $pageFn($params);
-
+        $response = $getPageFn();
         $this->afterCursor = $response->meta->has_more ? $response->meta->after_cursor : null;
+
         return $response->{$this->resourcesKey};
     }
 
     public function shouldGetPage($position) {
         return !$this->started || $this->afterCursor;
     }
+
+    public function params()
+    {
+        $result = array_merge($this->params, $this->paginationParams(), $this->sortParams());
+        $result = $this->unsetObpParams($result);
+
+        return $result;
+    }
+    /**
+     * The params that are needed to ordering in CBP (eg: ["sort" => "-age"])
+     * If OBP params are passed, they are converted to CBP
+     *
+     * OBP: https://{subdomain}.zendesk.com/api/v2/tickets?sort_order=desc&sort_by=updated_at&per_page=2
+     * CBP: https://{subdomain}.zendesk.com/api/v2/tickets?sort=-updated_at&page[size]=2
+     *
+     * @return array all params with CBP sorting order
+     */
+    private function sortParams()
+    {
+        if (isset($this->params['sort_by']) && !isset($this->params['sort'])) {
+            $direction = (isset($this->params['sort_order']) && strtolower($this->params['sort_order']) === 'desc') ? '-' : '';
+            return array_merge($this->params, ['sort' => $direction . $this->params['sort_by']]);
+        } else {
+            return [];
+        }
+    }
+    /**
+     * The params that are needed to for pagination (eg: ["page[size]" => "100"])
+     * If OBP params are passed, they are converted to CBP
+     *
+     * @return array all params with CBP sorting order
+     */
+    private function paginationParams()
+    {
+        $result = isset($this->afterCursor) ? ['page[after]' => $this->afterCursor] : [];
+
+        return array_merge(['page[size]' => $this->pageSize()], $result);
+    }
+
+    private function unsetObpParams($params)
+    {
+        unset(
+            $params['page'],
+            $params['per_page'],
+            $params['sort_by'],
+            $params['sort_order']
+        );
+        return $params;
+    }
 }

src/Zendesk/API/Traits/Utility/Pagination/ObpStrategy.php

@@ -10,16 +10,20 @@ class ObpStrategy extends AbstractStrategy
 {
     private $pageNumber = 0;
 
-    public function getPage($pageFn)
+    public function page($getPageFn)
     {
         ++$this->pageNumber;
-        $params = ['page' => $this->pageNumber, 'page_size' => $this->pageSize];
-        $response = $pageFn($params);
+        $response = $getPageFn();
 
         return $response->{$this->resourcesKey};
     }
 
     public function shouldGetPage($position) {
-        return $this->pageNumber == 0 || $position >= $this->pageNumber * $this->pageSize;
+        return $this->pageNumber == 0 || $position >= $this->pageNumber * $this->pageSize();
+    }
+    public function paramsWithPagination()
+    {
+        return ['page' => $this->pageNumber, 'per_page' => $this->pageSize()];
+
     }
 }

src/Zendesk/API/Traits/Utility/Pagination/PaginationIterator.php

@@ -2,25 +2,25 @@
 
 namespace Zendesk\API\Traits\Utility\Pagination;
 
+const DEFAULT_PAGE_SIZE = 100;
+
 use Iterator;
 
 class PaginationIterator implements Iterator
 {
-    private $position = 0;
-    private $page = [];
-    private $strategy;
-    private $params;
-
     /**
-     * @var mixed use trait FindAll. The object handling the list, Ie: `$client->{clientList}()`
+     * @var mixed using trait FindAll. The object handling the list, Ie: `$client->{clientList}()`
+     * Eg: `$client->tickets()` which uses FindAll
      */
     private $clientList;
+    private $strategy;
+    private $position = 0;
+    private $page = [];
 
-    public function __construct($clientList, AbstractStrategy $strategy, $params = [])
+    public function __construct($clientList, AbstractStrategy $strategy)
     {
         $this->clientList = $clientList;
         $this->strategy = $strategy;
-        $this->params = $params;
     }
 
     public function key()
@@ -59,10 +59,10 @@ private function getPageIfNeeded()
             return;
         }
 
-        $pageFn = function ($paginationParams = []) {
-            return $this->clientList->findAll(array_merge($this->params, $paginationParams));
+        $getPageFn = function () {
+            return $this->clientList->findAll($this->strategy->params());
         };
 
-        $this->page = array_merge($this->page, $this->strategy->getPage($pageFn));
+        $this->page = array_merge($this->page, $this->strategy->page($getPageFn));
     }
 }

src/Zendesk/API/Traits/Utility/Pagination/SinglePageStrategy.php

@@ -11,10 +11,10 @@ class SinglePageStrategy extends AbstractStrategy
 {
     protected $started = false;
 
-    public function getPage($pageFn)
+    public function page($getPageFn)
     {
         $this->started = true;
-        $response = $pageFn();
+        $response = $getPageFn();
 
         return $response->{$this->resourcesKey};
     }