Add canCreateBoards to capabilities and update documentation

Signed-off-by: Julius Härtl <jus@bitgrid.net>

docs/API-Nextcloud.md

@@ -1,5 +1,34 @@
 # Nextcloud APIs
 
+## Capabilities
+
+The [Nextcloud Capabilities API](https://docs.nextcloud.com/server/latest/developer_manual/client_apis/OCS/ocs-api-overview.html#capabilities-api) provides the following information for the Deck app:
+
+- `version` Current version of the Deck app running
+- `canCreateBoards` Ability of the current user to create new boards for themselves
+
+```
+{
+  "ocs": {
+    "meta": {
+      "status": "ok",
+      "statuscode": 200,
+      "message": "OK"
+    },
+    "data": {
+      "capabilities": {
+        "deck": {
+          "version": "0.8.0",
+          "canCreateBoards": true
+        },
+      }
+    }
+  }
+}
+```
+
+
+
 ## Available sharees
 
 When sharing a board to a user, group or circle, the possible sharees can be obtained though the files_sharing API.

lib/Capabilities.php

@@ -23,10 +23,23 @@
 
 namespace OCA\Deck;
 
+use OCA\Deck\Service\PermissionService;
+use OCP\App\IAppManager;
 use OCP\Capabilities\ICapability;
 
 class Capabilities implements ICapability {
 
+	/** @var IAppManager */
+	private $appManager;
+	/**  @var PermissionService */
+	private $permissionService;
+
+
+	public function __construct(IAppManager $appManager, PermissionService $permissionService) {
+		$this->appManager = $appManager;
+		$this->permissionService = $permissionService;
+	}
+
 	/**
 	 * Function an app uses to return the capabilities
 	 *
@@ -36,7 +49,8 @@ class Capabilities implements ICapability {
 	public function getCapabilities() {
 		return [
 			'deck' => [
-				'version' => \OC::$server->getAppManager()->getAppVersion('deck')
+				'version' => $this->appManager->getAppVersion('deck'),
+				'canCreateBoards' => $this->permissionService->canCreate()
 			]
 		];
 	}