Binary buffers

Author: martinRenou

packages/voila/src/manager.ts

@@ -196,35 +196,49 @@ export class WidgetManager extends JupyterLabManager {
 
   async _build_models(): Promise<{ [key: string]: base.WidgetModel }> {
     const models: { [key: string]: base.WidgetModel } = {};
-    const comm_id = base.uuid();
+    const commId = base.uuid();
     const initComm = await this._create_comm(
       'jupyter.widget.control',
-      comm_id,
+      commId,
       { widgets: null }
     );
 
-    const widgets_info: any = await new Promise(resolve => {
+    const [widgetsInfo, buffers]: any = await new Promise(resolve => {
       initComm.on_msg(msg => {
         const info = JSON.parse(
           Buffer.from(new Int8Array(msg.buffers[0].buffer)).toString('utf-8')
         );
-        resolve(info);
+        resolve([info, msg.buffers.slice(1)]);
       });
     });
 
     initComm.close();
 
-    const widget_states: any = widgets_info[0];
-    // const buffers: any = widgets_info[1];
+    const widgetStates: any = widgetsInfo[0];
 
-    const widget_promises: Promise<base.WidgetModel>[] = [];
+    // Extract buffer paths
+    // Why do we have to do this? Is there another way?
+    const bufferPaths: any = {};
+    for (const bufferPath of widgetsInfo[1]) {
+      if (!bufferPaths[bufferPath[0]]) {
+        bufferPaths[bufferPath[0]] = [];
+      }
+      bufferPaths[bufferPath[0]].push(bufferPath.slice(1));
+    };
+
+    const widgetPromises: Promise<base.WidgetModel>[] = [];
 
-    for (const widget_id in widget_states) {
-      const state = widget_states[widget_id];
+    for (const widget_id in widgetStates) {
+      const state = widgetStates[widget_id];
 
       try {
         const comm = await this._create_comm('jupyter.widget', widget_id);
 
+        // If we have binary buffers
+        if (widget_id in bufferPaths) {
+          base.put_buffers(state, bufferPaths[widget_id], buffers);
+        }
+
         const modelPromise = this.new_model(
           {
             model_name: state.model_name,
@@ -235,15 +249,15 @@ export class WidgetManager extends JupyterLabManager {
           },
           state.state
         );
-        widget_promises.push(modelPromise);
+        widgetPromises.push(modelPromise);
       } catch (error) {
         // Failed to create a widget model, we continue creating other models so that
         // other widgets can render
         console.error(error);
       }
     }
 
-    const widgets = await Promise.all(widget_promises);
+    const widgets = await Promise.all(widgetPromises);
     for (const model of widgets) {
       models[model.model_id] = model;
     }