Support InventoryItem and InventoryLevel

Author: baldrs

README.md

@@ -254,6 +254,8 @@ Some resources are available directly, some resources are only available through
 - [Event](https://help.shopify.com/api/reference/event/)
 - [FulfillmentService](https://help.shopify.com/api/reference/fulfillmentservice)
 - [GiftCard](https://help.shopify.com/api/reference/gift_card) _(Shopify Plus Only)_
+- [InventoryItem](https://help.shopify.com/api/reference/inventoryitem)
+- [InventoryLevel](https://help.shopify.com/api/reference/inventorylevel)
 - [Location](https://help.shopify.com/api/reference/location/) _(read only)_
 - [Metafield](https://help.shopify.com/api/reference/metafield)
 - [Multipass](https://help.shopify.com/api/reference/multipass) _(Shopify Plus Only, API not available yet)_
@@ -358,6 +360,14 @@ The custom methods are specific to some resources which may not be available for
     - [search()](https://help.shopify.com/api/reference/gift_card#search)
     Search for gift cards matching supplied query
 
+- InventoryLevel ->
+    - [adjust($data)](https://help.shopify.com/api/reference/inventorylevel#adjust)
+    Adjust inventory level.
+    - [connect($data)](https://help.shopify.com/api/reference/inventorylevel#connect)
+    Connect an inventory item to a location.
+    - [set($data)](https://help.shopify.com/api/reference/inventorylevel#set)
+    Set an inventory level for a single inventory item within a location.
+    
 - Order ->
     - [close()](https://help.shopify.com/api/reference/order#close)
     Close an Order

lib/InventoryItem.php

@@ -0,0 +1,15 @@
+<?php
+/**
+ * @author Arsenii Lozytskyi <[email protected]>
+ * Created at 04/15/18 02:25 PM UTC+03:00
+ *
+ * @see https://help.shopify.com/api/reference/inventoryitem
+ */
+
+namespace PHPShopify;
+
+class InventoryItem extends ShopifyResource
+{
+    /** @inheritDoc */
+    protected $resourceKey = 'inventory_item';
+}

lib/InventoryLevel.php

@@ -0,0 +1,29 @@
+<?php
+/**
+ * @author Arsenii Lozytskyi <[email protected]>
+ * Created at 04/15/18 02:31 PM UTC+03:00
+ *
+ * @see https://help.shopify.com/api/reference/inventorylevel
+ */
+
+namespace PHPShopify;
+
+/**
+ * Class InventoryLevel
+ *
+ * @method array adjust($data)  Adjust inventory level.
+ * @method array connect($data) Connect an inventory item to a location.
+ * @method array set($data)     Sets an inventory level for a single inventory item within a location.
+ */
+class InventoryLevel extends ShopifyResource
+{
+    /** @inheritDoc */
+    protected $resourceKey = 'inventory_level';
+
+    /** @inheritDoc */
+    protected $customPostActions = [
+        'adjust',
+        'connect',
+        'set',
+    ];
+}

lib/ShopifyResource.php

@@ -48,7 +48,7 @@ abstract class ShopifyResource
 
     /**
      * List of child Resource names / classes
-     * 
+     *
      * If any array item has an associative key => value pair, value will be considered as the resource name
      * (by which it will be called) and key will be the associated class name.
      *
@@ -498,4 +498,4 @@ public function processResponse($responseArray, $dataKey = null)
             return $responseArray;
         }
     }
-}
+}

lib/ShopifySDK.php

@@ -102,6 +102,8 @@ class ShopifySDK
         'Event',
         'FulfillmentService',
         'GiftCard',
+        'InventoryItem',
+        'InventoryLevel',
         'Location',
         'Metafield',
         'Multipass',
@@ -296,4 +298,4 @@ public static function checkApiCallLimit($firstCallWait = false)
 
         static::$microtimeOfLastApiCall = microtime(true);
     }
-}
+}