feat: Add shared objects to embed-widget

packages/embed-widget/src/App.tsx

@@ -63,12 +63,17 @@
 function App(): JSX.Element {
   const [error, setError] = useState<string>();
   const [definition, setDefinition] = useState<dh.ide.VariableDefinition>();
+  const [sharedReady, setSharedReady] = useState<boolean>(false);
   const searchParams = useMemo(
     () => new URLSearchParams(window.location.search),
     []
   );
   // Get the widget name from the query param `name`.
   const name = searchParams.get('name');
+  // Get the type of shared object from the query param,
+  // which is necessary if the widget is shared.
+  const type = searchParams.get('type');
+  const isShared = searchParams.get('isShared');
   const api = useApi();
   const connection = useConnection();
   const client = useClient();
@@ -115,34 +120,86 @@
             )
           );
 
-          log.debug(`Loading widget definition for ${name}...`);
+          if (isShared === 'true') {
+            log.debug(`Checking if shared parameters are valid...`);
 
-          const newDefinition = await fetchVariableDefinition(connection, name);
+            if (type == null) {
+              throw new Error('Missing URL parameter "type"');
+            }
 
-          setDefinition(newDefinition);
+            setSharedReady(true);
 
-          log.debug(`Widget definition successfully loaded for ${name}`);
+            log.debug(`Shared parameters are valid`);
+          } else {
+            log.debug(`Loading widget definition for ${name}...`);
+
+            const newDefinition = await fetchVariableDefinition(
+              connection,
+              name
+            );
+
+            setDefinition(newDefinition);
+
+            log.debug(`Widget definition successfully loaded for ${name}`);
+          }
         } catch (e: unknown) {
           log.error(`Unable to load widget definition for ${name}`, e);
           setError(`${e}`);
         }
       }
       initApp();
     },
-    [api, client, connection, dispatch, name, serverConfig, user]
+    [
+      api,
+      client,
+      connection,
+      dispatch,
+      name,
+      serverConfig,
+      user,
+      isShared,
+      type,
+    ]
   );
 
-  const isLoaded = definition != null && error == null;
-  const isLoading = definition == null && error == null;
+  const isLoaded =
+    (definition != null || sharedReady != false) && error == null;
+  const isLoading = definition == null && sharedReady == false && error == null;
+
+  type ConnectionWithGetSharedObject = dh.IdeConnection & {
+    getSharedObject(name: string, type: string): Promise<unknown>;
+  };
+
+  function isConnectionWithGetSharedObject(
+    connection: dh.IdeConnection
+  ): connection is ConnectionWithGetSharedObject {
+    return (
+      'getSharedObject' in connection &&
+      typeof connection.getSharedObject === 'function'
+    );
+  }
 
   const fetch = useMemo(() => {
-    if (definition == null) {
+    if (definition == null && !sharedReady) {
       return async () => {
         throw new Error('Definition is null');
       };
     }
-    return () => connection.getObject(definition);
-  }, [connection, definition]);
+    return () => {
+      if (name != null && type != null) {
+        if (isConnectionWithGetSharedObject(connection)) {
+          return connection.getSharedObject(name, type);
+        }
+        throw new Error(
+          'Connection does not have getSharedObject method. Cannot fetch shared object.'
+        );
+      }
+      if (definition != null) {
+        return connection.getObject(definition);
+      }
+      throw new Error('Definition is null or shared parameters are not set');
+    };
+  }, [connection, definition, sharedReady, name, type]);
 
   const [goldenLayout, setGoldenLayout] = useState<GoldenLayout | null>(null);
   const [dashboardId, setDashboardId] = useState('default-embed-widget'); // Can't be DEFAULT_DASHBOARD_ID because its dashboard layout is not stored in dashboardData
@@ -175,16 +232,40 @@
   const [hasEmittedWidget, setHasEmittedWidget] = useState(false);
 
   const handleDashboardInitialized = useCallback(() => {
-    if (goldenLayout == null || definition == null || hasEmittedWidget) {
+    if (
+      goldenLayout == null ||
+      (definition == null && sharedReady == null) ||
+      hasEmittedWidget
+    ) {
       return;
     }
-
     setHasEmittedWidget(true);
+
+    let widget = null;
+    if (sharedReady != null) {
+      widget = {
+        type,
+        name,
+      } as dh.ide.VariableDescriptor;
+    } else if (definition != null) {
+      widget = getVariableDescriptor(definition);
+    } else {
+      return;
+    }
+
     emitPanelOpen(goldenLayout.eventHub, {
       fetch,
-      widget: getVariableDescriptor(definition),
+      widget,
     });
-  }, [goldenLayout, definition, fetch, hasEmittedWidget]);
+  }, [
+    goldenLayout,
+    definition,
+    fetch,
+    hasEmittedWidget,
+    name,
+    type,
+    sharedReady,
+  ]);
 
   const allDashboardData = useSelector(getAllDashboardsData);