feat: support nested STRUCT and ARRAY data display in anywidget mode

bigframes/display/html.py

@@ -28,7 +28,7 @@
 
 import bigframes
 from bigframes._config import display_options, options
-from bigframes.display import plaintext
+from bigframes.display import _flatten, plaintext
 import bigframes.formatting_helpers as formatter
 
 if typing.TYPE_CHECKING:
@@ -48,13 +48,17 @@ def render_html(
     orderable_columns: list[str] | None = None,
     max_columns: int | None = None,
 ) -> str:
-    """Render a pandas DataFrame to HTML with specific styling."""
+    """Render a pandas DataFrame to HTML with specific styling and nested data support."""
+    # Flatten nested data first
+    flatten_result = _flatten.flatten_nested_data(dataframe)
+    flat_df = flatten_result.dataframe
+
     orderable_columns = orderable_columns or []
     classes = "dataframe table table-striped table-hover"
     table_html_parts = [f'<table border="1" class="{classes}" id="{table_id}">']
 
     # Handle column truncation
-    columns = list(dataframe.columns)
+    columns = list(flat_df.columns)
     if max_columns is not None and max_columns > 0 and len(columns) > max_columns:
         half = max_columns // 2
         left_columns = columns[:half]
@@ -70,11 +74,20 @@ def render_html(
 
     table_html_parts.append(
         _render_table_header(
-            dataframe, orderable_columns, left_columns, right_columns, show_ellipsis
+            flat_df, orderable_columns, left_columns, right_columns, show_ellipsis
         )
     )
     table_html_parts.append(
-        _render_table_body(dataframe, left_columns, right_columns, show_ellipsis)
+        _render_table_body(
+            flat_df,
+            flatten_result.row_labels,
+            flatten_result.continuation_rows,
+            flatten_result.cleared_on_continuation,
+            flatten_result.nested_columns,
+            left_columns,
+            right_columns,
+            show_ellipsis,
+        )
     )
     table_html_parts.append("</table>")
     return "".join(table_html_parts)
@@ -117,6 +130,10 @@ def render_col_header(col):
 
 def _render_table_body(
     dataframe: pd.DataFrame,
+    row_labels: list[str] | None,
+    continuation_rows: set[int] | None,
+    clear_on_continuation: list[str],
+    nested_originated_columns: set[str],
     left_columns: list[Any],
     right_columns: list[Any],
     show_ellipsis: bool,
@@ -126,30 +143,39 @@ def _render_table_body(
     precision = options.display.precision
 
     for i in range(len(dataframe)):
-        body_parts.append("    <tr>")
+        row_class = ""
+        orig_row_idx = None
+        is_continuation = False
+
+        if row_labels:
+            orig_row_idx = row_labels[i]
+
+        if continuation_rows and i in continuation_rows:
+            is_continuation = True
+            row_class = "array-continuation"
+
+        if orig_row_idx is not None:
+            body_parts.append(
+                f'    <tr class="{row_class}" data-orig-row="{orig_row_idx}">'
+            )
+        else:
+            body_parts.append("    <tr>")
+
         row = dataframe.iloc[i]
 
         def render_col_cell(col_name):
             value = row[col_name]
             dtype = dataframe.dtypes.loc[col_name]  # type: ignore
-            align = "right" if _is_dtype_numeric(dtype) else "left"
-
-            # TODO(b/438181139): Consider semi-exploding ARRAY/STRUCT columns
-            # into multiple rows/columns like the BQ UI does.
-            if pandas.api.types.is_scalar(value) and pd.isna(value):
-                body_parts.append(
-                    f'      <td class="cell-align-{align}">'
-                    '<em class="null-value">&lt;NA&gt;</em></td>'
-                )
-            else:
-                if isinstance(value, float):
-                    cell_content = f"{value:.{precision}f}"
-                else:
-                    cell_content = str(value)
-                body_parts.append(
-                    f'      <td class="cell-align-{align}">'
-                    f"{html.escape(cell_content)}</td>"
-                )
+            cell_html = _render_cell(
+                value,
+                dtype,
+                is_continuation,
+                str(col_name),
+                clear_on_continuation,
+                nested_originated_columns,
+                precision,
+            )
+            body_parts.append(cell_html)
 
         for col in left_columns:
             render_col_cell(col)
@@ -166,6 +192,43 @@ def render_col_cell(col_name):
     return "\n".join(body_parts)
 
 
+def _render_cell(
+    value: Any,
+    dtype: Any,
+    is_continuation: bool,
+    col_name_str: str,
+    clear_on_continuation: list[str],
+    nested_originated_columns: set[str],
+    precision: int,
+) -> str:
+    """Render a single cell of the HTML table."""
+    if is_continuation and col_name_str in clear_on_continuation:
+        return "      <td></td>"
+
+    if col_name_str in nested_originated_columns:
+        align = "left"
+    else:
+        align = "right" if _is_dtype_numeric(dtype) else "left"
+
+    if pandas.api.types.is_scalar(value) and pd.isna(value):
+        if is_continuation:
+            # For padding nulls in continuation rows, show empty cell
+            return f'      <td class="cell-align-{align}"></td>'
+        else:
+            # For primary nulls, keep showing the <NA> indicator but maybe styled
+            return (
+                f'      <td class="cell-align-{align}">'
+                '<em class="null-value">&lt;NA&gt;</em></td>'
+            )
+
+    if isinstance(value, float):
+        cell_content = f"{value:.{precision}f}"
+    else:
+        cell_content = str(value)
+
+    return f'      <td class="cell-align-{align}">' f"{html.escape(cell_content)}</td>"
+
+
 def _obj_ref_rt_to_html(obj_ref_rt: str) -> str:
     obj_ref_rt_json = json.loads(obj_ref_rt)
     obj_ref_details = obj_ref_rt_json["objectref"]["details"]

bigframes/display/table_widget.css

@@ -26,6 +26,7 @@
   --bf-header-bg: #f5f5f5;
   --bf-null-fg: gray;
   --bf-row-even-bg: #f5f5f5;
+  --bf-row-hover-bg: #e8eaed;
   --bf-row-odd-bg: white;
 
   background-color: var(--bf-bg);
@@ -59,6 +60,7 @@
     --bf-header-bg: var(--vscode-editor-background, black);
     --bf-null-fg: #aaa;
     --bf-row-even-bg: #202124;
+    --bf-row-hover-bg: #4c4c4c;
     --bf-row-odd-bg: #383838;
   }
 }
@@ -75,6 +77,7 @@ body[data-theme='dark'] .bigframes-widget.bigframes-widget {
   --bf-header-bg: var(--vscode-editor-background, black);
   --bf-null-fg: #aaa;
   --bf-row-even-bg: #202124;
+  --bf-row-hover-bg: #4c4c4c;
   --bf-row-odd-bg: #383838;
 }
 
@@ -245,3 +248,8 @@ body[data-theme='dark'] .bigframes-widget.bigframes-widget {
 .bigframes-widget .debug-info {
   border-top: 1px solid var(--bf-border-color);
 }
+
+.bigframes-widget table tbody tr:hover td,
+.bigframes-widget table tbody tr td.row-hover {
+  background-color: var(--bf-row-hover-bg);
+}

bigframes/display/table_widget.js

@@ -268,6 +268,38 @@ function render({ model, el }) {
       }
     });
 
+    // Add hover effect for flattened rows
+    const rows = tableContainer.querySelectorAll('tbody tr');
+    rows.forEach((row) => {
+      row.addEventListener('mouseover', () => {
+        const origRow = row.getAttribute('data-orig-row');
+        if (origRow !== null) {
+          const groupRows = tableContainer.querySelectorAll(
+            `tr[data-orig-row="${origRow}"]`,
+          );
+          groupRows.forEach((r) => {
+            r.querySelectorAll('td').forEach((cell) => {
+              cell.classList.add('row-hover');
+            });
+          });
+        }
+      });
+
+      row.addEventListener('mouseout', () => {
+        const origRow = row.getAttribute('data-orig-row');
+        if (origRow !== null) {
+          const groupRows = tableContainer.querySelectorAll(
+            `tr[data-orig-row="${origRow}"]`,
+          );
+          groupRows.forEach((r) => {
+            r.querySelectorAll('td').forEach((cell) => {
+              cell.classList.remove('row-hover');
+            });
+          });
+        }
+      });
+    });
+
     updateButtonStates();
   }
 
@@ -329,4 +361,4 @@ function render({ model, el }) {
   handleErrorMessageChange();
 }
 
-export default { render };
+export { render };