Lock widget room ID when added

This changes the widget room ID available to widget URL templates so that it's
locked to the room the widget was added in.

Fixes https://github.com/vector-im/element-web/issues/16337

src/components/views/dialogs/ModalWidgetDialog.tsx

@@ -35,13 +35,13 @@ import {
 } from "matrix-widget-api";
 import {StopGapWidgetDriver} from "../../../stores/widgets/StopGapWidgetDriver";
 import {MatrixClientPeg} from "../../../MatrixClientPeg";
-import RoomViewStore from "../../../stores/RoomViewStore";
 import {OwnProfileStore} from "../../../stores/OwnProfileStore";
 import { arrayFastClone } from "../../../utils/arrays";
 import { ElementWidget } from "../../../stores/widgets/StopGapWidget";
 
 interface IProps {
     widgetDefinition: IModalWidgetOpenRequestData;
+    widgetRoomId?: string;
     sourceWidgetId: string;
     onFinished(success: boolean, data?: IModalWidgetReturnData): void;
 }
@@ -123,7 +123,7 @@ export default class ModalWidgetDialog extends React.PureComponent<IProps, IStat
 
     public render() {
         const templated = this.widget.getCompleteUrl({
-            currentRoomId: RoomViewStore.getRoomId(),
+            widgetRoomId: this.props.widgetRoomId,
             currentUserId: MatrixClientPeg.get().getUserId(),
             userDisplayName: OwnProfileStore.instance.displayName,
             userHttpAvatarUrl: OwnProfileStore.instance.getHttpAvatarUrl(),

src/stores/ModalWidgetStore.ts

@@ -48,11 +48,16 @@ export class ModalWidgetStore extends AsyncStoreWithClient<IState> {
         return !this.modalInstance;
     };
 
-    public openModalWidget = (requestData: IModalWidgetOpenRequestData, sourceWidget: Widget) => {
+    public openModalWidget = (
+        requestData: IModalWidgetOpenRequestData,
+        sourceWidget: Widget,
+        widgetRoomId?: string,
+    ) => {
         if (this.modalInstance) return;
         this.openSourceWidgetId = sourceWidget.id;
         this.modalInstance = Modal.createTrackedDialog('Modal Widget', '', ModalWidgetDialog, {
             widgetDefinition: {...requestData},
+            widgetRoomId,
             sourceWidgetId: sourceWidget.id,
             onFinished: (success: boolean, data?: IModalWidgetReturnData) => {
                 if (!success) {

src/stores/widgets/StopGapWidget.ts

@@ -190,7 +190,7 @@ export class StopGapWidget extends EventEmitter {
 
     private runUrlTemplate(opts = {asPopout: false}): string {
         const templated = this.mockWidget.getCompleteUrl({
-            currentRoomId: RoomViewStore.getRoomId(),
+            widgetRoomId: this.roomId,
             currentUserId: MatrixClientPeg.get().getUserId(),
             userDisplayName: OwnProfileStore.instance.displayName,
             userHttpAvatarUrl: OwnProfileStore.instance.getHttpAvatarUrl(),