API: ETag/If-None-Match for Get single note

docs/api/v1.md

@@ -91,9 +91,11 @@ No valid authentication credentials supplied.
 | Parameter | Type | Description |
 |:------|:-----|:-----|
 | `id` | integer, required (path) | ID of the note to query. |
+| `If-None-Match` | HTTP header, optional | Use this in order to reduce transferred data size (see [HTTP ETag](https://en.wikipedia.org/wiki/HTTP_ETag)). You should use the value from the note's attribute `etag` or from the last request's HTTP response header `ETag`. | 1.2 |
 
 #### Response
 ##### 200 OK
+- **HTTP Header**: `ETag` (see [HTTP ETag](https://en.wikipedia.org/wiki/HTTP_ETag)). The value is identical to the note's attribute `etag` (see section [Note attributes](#note-attributes)).
 - **Body**: note (see section [Note attributes](#note-attributes)), example:
 ```js
 {

lib/Controller/NotesApiController.php

@@ -68,7 +68,10 @@ class NotesApiController extends ApiController {
 		return $this->helper->handleErrorResponse(function () use ($id, $exclude) {
 			$exclude = explode(',', $exclude);
 			$note = $this->service->get($this->helper->getUID(), $id);
-			return $this->helper->getNoteData($note, $exclude);
+			$noteData = $this->helper->getNoteData($note, $exclude);
+			return (new JSONResponse($noteData))
+				->setETag($noteData['etag'])
+			;
 		});
 	}
 

package-lock.json

@@ -5029,6 +5029,19 @@
 			"resolved": "https://registry.npmjs.org/fs.realpath/-/fs.realpath-1.0.0.tgz",
 			"integrity": "sha1-FQStJSMVjKpA20onh8sBQRmU6k8="
 		},
+		"node_modules/fsevents": {
+			"version": "2.3.2",
+			"resolved": "https://registry.npmjs.org/fsevents/-/fsevents-2.3.2.tgz",
+			"integrity": "sha512-xiqMQR4xAeHTuB9uWm+fFRcIOgKBMiOBP+eXiyT7jsgVCq1bkVygt00oASowB7EdtpOHaaPgKt812P9ab+DDKA==",
+			"hasInstallScript": true,
+			"optional": true,
+			"os": [
+				"darwin"
+			],
+			"engines": {
+				"node": "^8.16.0 || ^10.6.0 || >=11.0.0"
+			}
+		},
 		"node_modules/function-bind": {
 			"version": "1.1.1",
 			"resolved": "https://registry.npmjs.org/function-bind/-/function-bind-1.1.1.tgz",
@@ -14816,6 +14829,12 @@
 			"resolved": "https://registry.npmjs.org/fs.realpath/-/fs.realpath-1.0.0.tgz",
 			"integrity": "sha1-FQStJSMVjKpA20onh8sBQRmU6k8="
 		},
+		"fsevents": {
+			"version": "2.3.2",
+			"resolved": "https://registry.npmjs.org/fsevents/-/fsevents-2.3.2.tgz",
+			"integrity": "sha512-xiqMQR4xAeHTuB9uWm+fFRcIOgKBMiOBP+eXiyT7jsgVCq1bkVygt00oASowB7EdtpOHaaPgKt812P9ab+DDKA==",
+			"optional": true
+		},
 		"function-bind": {
 			"version": "1.1.1",
 			"resolved": "https://registry.npmjs.org/function-bind/-/function-bind-1.1.1.tgz",