Add includes and excludes support to endpoint configuration (#41)

Resolves #40

Author: qrazi

README.md

@@ -201,6 +201,46 @@ Possible values are:
 - `'jsonFeed'` – formats data based on [JSON Feed V1](https://jsonfeed.org/version/1) (see the [JSON Feed](#json-feed) example below).
 - A custom serializer instance.
 
+#### `includes`
+
+The [include names](http://fractal.thephpleague.com/transformers/#including-data) that should be included for the current request, if any.
+
+```php
+'includes' => craft()->request->getQuery('include'),
+```
+
+Note that this setting requires a custom transformer class that’s prepped to handle includes:
+
+```php
+class MyTransformerClassName extends TransformerAbstract
+{
+    protected $availableIncludes = ['author'];
+
+    public function includeAuthor(EntryModel $entry)
+    {
+        return $this->item($entry->author, function(UserModel($author) {
+            return [
+                'id' => $author->id,
+                'name' => $author->name,
+            ];
+        });
+    }
+    
+    // ...
+}
+```
+
+#### `excludes`
+
+
+The [include names](http://fractal.thephpleague.com/transformers/#including-data) that should be excluded for the current request, which would otherwise have been included (e.g. if they were listed as a default include), if any.
+
+```php
+'excludes' => 'author',
+```
+
+Like [`includes`](#includes), this setting requires a custom transformer class.
+
 #### `jsonOptions`
 
 The value of the `$options` argument that will be passed to [`json_encode()`](http://php.net/manual/en/function.json-encode.php) when preparing the response. By default no options will be passed.

elementapi/controllers/ElementApiController.php

@@ -114,6 +114,14 @@ public function actionGetElements($configFactory = null, array $config = null)
 		}
 		$fractal->setSerializer($serializer);
 
+		// Set the includes
+		$includes = isset($config['includes']) ? $config['includes'] : [];
+		$fractal->parseIncludes($includes);
+
+		// Set the excludes
+		$excludes = isset($config['excludes']) ? $config['excludes'] : [];
+		$fractal->parseExcludes($excludes);
+
 		// Define the transformer
 		if (is_callable($config['transformer']) || $config['transformer'] instanceof TransformerAbstract)
 		{