Merge pull request #23 from mandrew9/main

Enable support for exporting 1D and 2D dataset slices.

app/utils.ts

@@ -5,18 +5,52 @@ import { vscode } from './vscode-api.js';
 // 2 GB = 2 * 1024 * 1024 * 1024 B
 export const MAX_SIZE_IN_BYTES = 2147483648;
 
-export const getExportURL: GetExportURL = (format, dataset, __, value) => {
+export const getExportURL: GetExportURL = (
+  format,
+  dataset,
+  selection,
+  value
+) => {
+  function doExport(payload: string): Blob {
+    // Send payload to `H5WebViewer` editor provider
+    vscode.postMessage({
+      type: MessageType.Export,
+      data: { format, name: dataset.name, payload },
+    });
+
+    return new Blob(); // doesn't matter as long as it's not falsy
+  }
+
   if (format === 'json') {
+    return async () => doExport(JSON.stringify(value, null, 2));
+  }
+
+  if (format === 'csv') {
     return async () => {
-      vscode.postMessage({
-        type: MessageType.Export,
-        data: {
-          format,
-          name: dataset.name,
-          payload: JSON.stringify(value, null, 2),
-        },
-      });
-      return new Blob(); // doesn't matter as long as it's not falsy
+      // Find dimensions of dataset/slice to export
+      // Note that there is currently no way to know if the dataset/slice is transposed - https://github.com/silx-kit/h5web/issues/1454
+      const dims = selection
+        ? dataset.shape.filter((_, index) => selection[index * 2] === ':')
+        : dataset.shape;
+
+      if (dims.length < 1 || dims.length > 2) {
+        throw new Error(
+          'Expected dataset/slice to export to have 1 or 2 dimensions'
+        );
+      }
+
+      let csv = '';
+      const [rows, cols = 1] = dims; // export 1D dataset/slice as column (i.e. 1 value per line)
+
+      for (let i = 0; i < rows; i += 1) {
+        for (let j = 0; j < cols; j += 1) {
+          csv += `${value[i * cols + j].toString()}${j < cols - 1 ? ',' : ''}`;
+        }
+
+        csv += i < rows - 1 ? '\n' : '';
+      }
+
+      return doExport(csv);
     };
   }