Added drawing update ability

app/Http/Controllers/ImageController.php

@@ -142,6 +142,32 @@ class ImageController extends Controller
         return response()->json($image);
     }
 
+    /**
+     * Replace the data content of a drawing.
+     * @param string $id
+     * @param Request $request
+     * @return \Illuminate\Contracts\Routing\ResponseFactory|\Illuminate\Http\JsonResponse|\Symfony\Component\HttpFoundation\Response
+     */
+    public function replaceDrawing(string $id, Request $request)
+    {
+        $this->validate($request, [
+            'image' => 'required|string'
+        ]);
+        $this->checkPermission('image-create-all');
+
+        $imageBase64Data = $request->get('image');
+        $image = $this->imageRepo->getById($id);
+        $this->checkOwnablePermission('image-update', $image);
+
+        try {
+            $image = $this->imageRepo->replaceDrawingContent($image, $imageBase64Data);
+        } catch (ImageUploadException $e) {
+            return response($e->getMessage(), 500);
+        }
+
+        return response()->json($image);
+    }
+
     /**
      * Get the content of an image based64 encoded.
      * @param $id

app/Repos/ImageRepo.php

@@ -156,6 +156,18 @@ class ImageRepo
         return $image;
     }
 
+    /**
+     * Replace the image content of a drawing.
+     * @param Image $image
+     * @param string $base64Uri
+     * @return Image
+     * @throws \BookStack\Exceptions\ImageUploadException
+     */
+    public function replaceDrawingContent(Image $image, string $base64Uri)
+    {
+        return $this->imageService->replaceImageDataFromBase64Uri($image, $base64Uri);
+    }
+
     /**
      * Update the details of an image via an array of properties.
      * @param Image $image

app/Services/ImageService.php

@@ -65,6 +65,31 @@ class ImageService extends UploadService
         return $this->saveNew($name, $data, $type, $uploadedTo);
     }
 
+    /**
+     * Replace the data for an image via a Base64 encoded string.
+     * @param Image $image
+     * @param string $base64Uri
+     * @return Image
+     * @throws ImageUploadException
+     */
+    public function replaceImageDataFromBase64Uri(Image $image, string $base64Uri)
+    {
+        $splitData = explode(';base64,', $base64Uri);
+        if (count($splitData) < 2) {
+            throw new ImageUploadException("Invalid base64 image data provided");
+        }
+        $data = base64_decode($splitData[1]);
+        $storage = $this->getStorage();
+
+        try {
+            $storage->put($image->path, $data);
+        } catch (Exception $e) {
+            throw new ImageUploadException(trans('errors.path_not_writable', ['filePath' => $image->path]));
+        }
+
+        return $image;
+    }
+
     /**
      * Gets an image from url and saves it to the database.
      * @param             $url