Adding variables (on the front side for now)

front/src/Phaser/Game/GameScene.ts

@@ -91,6 +91,8 @@ import { soundManager } from "./SoundManager";
 import { peerStore, screenSharingPeerStore } from "../../Stores/PeerStore";
 import { videoFocusStore } from "../../Stores/VideoFocusStore";
 import { biggestAvailableAreaStore } from "../../Stores/BiggestAvailableAreaStore";
+import { SharedVariablesManager } from "./SharedVariablesManager";
+import type {InitEvent} from "../../Api/Events/InitEvent";
 
 export interface GameSceneInitInterface {
     initPosition: PointInterface | null;
@@ -199,7 +201,8 @@ export class GameScene extends DirtyScene {
     private mapTransitioning: boolean = false; //used to prevent transitions happenning at the same time.
     private emoteManager!: EmoteManager;
     private preloading: boolean = true;
-    startPositionCalculator!: StartPositionCalculator;
+    private startPositionCalculator!: StartPositionCalculator;
+    private sharedVariablesManager!: SharedVariablesManager;
 
     constructor(private room: Room, MapUrlFile: string, customKey?: string | undefined) {
         super({
@@ -396,6 +399,23 @@ export class GameScene extends DirtyScene {
             });
         }
 
+
+        this.iframeSubscriptionList.push(iframeListener.readyStream.subscribe((iframe) => {
+            this.connectionAnswerPromise.then(connection => {
+                // Generate init message for an iframe
+                // TODO: merge with GameStateEvent
+                const initEvent: InitEvent = {
+                    variables: this.sharedVariablesManager.variables
+                }
+
+            });
+            // TODO: SEND INIT MESSAGE TO IFRAMES ONLY WHEN CONNECTION IS ESTABLISHED
+            // TODO: SEND INIT MESSAGE TO IFRAMES ONLY WHEN CONNECTION IS ESTABLISHED
+            // TODO: SEND INIT MESSAGE TO IFRAMES ONLY WHEN CONNECTION IS ESTABLISHED
+            // TODO: SEND INIT MESSAGE TO IFRAMES ONLY WHEN CONNECTION IS ESTABLISHED
+            // TODO: SEND INIT MESSAGE TO IFRAMES ONLY WHEN CONNECTION IS ESTABLISHED
+        }));
+
         // Now, let's load the script, if any
         const scripts = this.getScriptUrls(this.mapFile);
         for (const script of scripts) {
@@ -706,6 +726,9 @@ export class GameScene extends DirtyScene {
                     this.gameMap.setPosition(event.x, event.y);
                 });
 
+                // Set up variables manager
+                this.sharedVariablesManager = new SharedVariablesManager(this.connection, this.gameMap);
+
                 //this.initUsersPosition(roomJoinedMessage.users);
                 this.connectionAnswerPromiseResolve(onConnect.room);
                 // Analyze tags to find if we are admin. If yes, show console.
@@ -1148,6 +1171,7 @@ ${escapedMessage}
         this.peerStoreUnsubscribe();
         this.biggestAvailableAreaStoreUnsubscribe();
         iframeListener.unregisterAnswerer('getState');
+        this.sharedVariablesManager?.close();
 
         mediaManager.hideGameOverlay();
 

front/src/Phaser/Game/SharedVariablesManager.ts

@@ -0,0 +1,59 @@
+/**
+ * Handles variables shared between the scripting API and the server.
+ */
+import type {RoomConnection} from "../../Connexion/RoomConnection";
+import {iframeListener} from "../../Api/IframeListener";
+import type {Subscription} from "rxjs";
+import type {GameMap} from "./GameMap";
+import type {ITiledMapObject} from "../Map/ITiledMap";
+
+export class SharedVariablesManager {
+    private _variables = new Map<string, unknown>();
+    private iframeListenerSubscription: Subscription;
+    private variableObjects: Map<string, ITiledMapObject>;
+
+    constructor(private roomConnection: RoomConnection, private gameMap: GameMap) {
+        // We initialize the list of variable object at room start. The objects cannot be edited later
+        // (otherwise, this would cause a security issue if the scripting API can edit this list of objects)
+        this.variableObjects = SharedVariablesManager.findVariablesInMap(gameMap);
+
+        // When a variable is modified from an iFrame
+        this.iframeListenerSubscription = iframeListener.setVariableStream.subscribe((event) => {
+            const key = event.key;
+
+            if (!this.variableObjects.has(key)) {
+                const errMsg = 'A script is trying to modify variable "'+key+'" but this variable is not defined in the map.' +
+                    'There should be an object in the map whose name is "'+key+'" and whose type is "variable"';
+                console.error(errMsg);
+                throw new Error(errMsg);
+            }
+
+            this._variables.set(key, event.value);
+            // TODO: dispatch to the room connection.
+        });
+    }
+
+    private static findVariablesInMap(gameMap: GameMap): Map<string, ITiledMapObject> {
+        const objects = new Map<string, ITiledMapObject>();
+        for (const layer of gameMap.getMap().layers) {
+            if (layer.type === 'objectgroup') {
+                for (const object of layer.objects) {
+                    if (object.type === 'variable') {
+                        // We store a copy of the object (to make it immutable)
+                        objects.set(object.name, {...object});
+                    }
+                }
+            }
+        }
+        return objects;
+    }
+
+
+    public close(): void {
+        this.iframeListenerSubscription.unsubscribe();
+    }
+
+    get variables(): Map<string, unknown> {
+        return this._variables;
+    }
+}