implement save arrow data from perspective view (#88)

Author: RandomFractals

data/CTA-Ridership-by-Station.arrow

@@ -414,6 +414,11 @@ export class TableView {
       defaultUri: Uri.parse(dataFilePath).with({ scheme: 'file' })
     });
 
+    if (dataFileType === 'arrow') {
+      // convert data array to a buffer to save
+      data = Buffer.from(data);
+    }
+
     if (dataFileUri) {
       // save data
       // TODO: switch to using workspace.fs for data save

src/views/tableView.ts

@@ -317,7 +317,9 @@ async function saveData() {
 			viewData = JSON.stringify(jsonDataArray, null, 2);
 			break;
 		case 'arrow':
-			viewData = await view.to_arrow();
+			const arrayBuffer = await view.to_arrow();
+			const dataArray = new Uint8Array(arrayBuffer);
+			viewData = Array.from(dataArray);
 			break;
 	}