add function to save the whiteboard to a file

.gitignore

@@ -66,3 +66,4 @@ typings/
 .env
 
 /public/apidoc
+/savedBoards.json

README.md

@@ -165,7 +165,7 @@ Many more settings can be tweaked. All of them are described in the [default con
 
 ## Things you may want to know
 
-- Whiteboards are gone if you restart the Server, so keep that in mind (or save your whiteboard)
+- Whiteboards are gone if you restart the Server enable "enableFileDatabase" in the config file or export the board to prevent that.
 - You should be able to customize the layout without ever touching the whiteboard.js (take a look at index.html & main.js)
 
 ## ToDo

config.default.yml

@@ -6,6 +6,9 @@ backend:
   # Enable the function to save to a webdav-server (check README for more info) -- boolean
   enableWebdav: false
 
+  # Enable the function to save the whiteboard to a file so you save the state even on server restarts -- boolean
+  enableFileDatabase: true
+
   # Backend performance tweaks
   performance:
     # Whiteboard information broadcasting frequency (in Hz i.e. /s) -- number

scripts/config/config-schema.json

@@ -14,6 +14,9 @@
         "enableWebdav": {
           "type": "boolean"
         },
+        "enableFileDatabase": {
+          "type": "boolean"
+        },
         "performance": {
           "additionalProperties": false,
           "type": "object",

scripts/s_whiteboard.js

@@ -1,7 +1,23 @@
-//This file is only for saving the whiteboard. (Not to a file, only to RAM atm. Whiteboard is gone after server restart)
+//This file is only for saving the whiteboard.
+const fs = require("fs");
+const config = require("./config/config");
 
 var savedBoards = {};
 var savedUndos = {};
+var saveDelay = false;
+
+if (config.backend.enableFileDatabase) {
+    //read saved boards from file
+    fs.readFile("savedBoards.json", (err, data) => {
+        if (err) {
+            return console.log(
+                "Not persistend Whiteboard Datafile found... this is not a problem on the first start!"
+            );
+        }
+        savedBoards = JSON.parse(data);
+    });
+}
+
 module.exports = {
     handleEventsAndData: function (content) {
         var tool = content["t"]; //Tool witch is used
@@ -77,9 +93,7 @@ module.exports = {
             ].includes(tool)
         ) {
             //Save all this actions
-            if (!savedBoards[wid]) {
+            savedBoards[wid] = savedBoards[wid] ? savedBoards[wid] : [];
-                savedBoards[wid] = [];
-            }
             delete content["wid"]; //Delete id from content so we don't store it twice
             if (tool === "setTextboxText") {
                 for (var i = savedBoards[wid].length - 1; i >= 0; i--) {
@@ -94,6 +108,21 @@ module.exports = {
             }
             savedBoards[wid].push(content);
         }
+
+        if (config.backend.enableFileDatabase) {
+            //Save whiteboard to file
+            if (!saveDelay) {
+                saveDelay = true;
+                setTimeout(function () {
+                    saveDelay = false;
+                    fs.writeFile("savedBoards.json", JSON.stringify(savedBoards), (err) => {
+                        if (err) {
+                            return console.log(err);
+                        }
+                    });
+                }, 1000 * 10); //Save after 10 sec
+            }
+        }
     },
     loadStoredData: function (wid) {
         //Load saved whiteboard