feat: Airtable-style Grid/List UX optimizations

ROADMAP.md

@@ -746,6 +746,52 @@ ObjectUI is a universal Server-Driven UI (SDUI) engine built on React + Tailwind
 - [x] 11 new tests (SystemHubPage, AppManagementPage, PermissionManagementPage)
 - [x] Total: 20 system page tests passing
 
+### P1.13 Airtable Grid/List UX Optimization ✅
+
+> **Status:** Complete — Grid/List components now match Airtable UX patterns for date formatting, row interactions, editing, density, headers, filters, and empty states.
+
+**Date Field Humanized Format:**
+- [x] `formatDate`, `formatDateTime`, `DateTimeCellRenderer` use browser locale (`undefined` instead of `'en-US'`)
+- [x] All date columns auto-format to localized human-readable format (e.g., "2024/2/28 12:57am")
+
+**Row Hover "Open >" Button:**
+- [x] Expand button changed from icon-only `<Expand>` to text "Open >" with `<ChevronRight>` icon
+- [x] Consistent across Grid and ListView (shown on row hover)
+
+**Single-Click Edit Mode:**
+- [x] Added `singleClickEdit` prop to `DataTableSchema` and `ObjectGridSchema`
+- [x] When true, clicking a cell enters edit mode (instead of double-click)
+
+**Default Compact Row Height:**
+- [x] ObjectGrid default changed from `'medium'` to `'compact'` (32-36px rows)
+- [x] ListView default density changed from `'comfortable'` to `'compact'`
+- [x] Row height toggle preserved in toolbar
+
+**Single-Click Edit Mode:**
+- [x] Added `singleClickEdit` prop to `DataTableSchema` and `ObjectGridSchema`
+- [x] ObjectGrid defaults `singleClickEdit` to `true` (click-to-edit by default)
+- [x] InlineEditing component already compatible (click-to-edit native)
+
+**Column Header Minimal Style:**
+- [x] Headers use `text-xs font-normal text-muted-foreground` (was `text-[11px] font-semibold uppercase tracking-wider`)
+- [x] Sort arrows inline with header text
+
+**Filter Pill/Chip Styling:**
+- [x] Filter badges use `rounded-full` for Airtable-style pill appearance
+- [x] "More" overflow button matches pill styling
+
+**Column Width Auto-Sizing:**
+- [x] Auto column width estimation based on header and data content (80-400px range)
+- [x] Samples up to 50 rows for width calculation
+
+**Row Selection Checkbox Style:**
+- [x] Added `selectionStyle` prop ('always'|'hover') to `DataTableSchema`
+- [x] 'hover' mode shows checkboxes only on row hover
+
+**Empty Table Ghost Row:**
+- [x] Empty tables show 3 ghost placeholder rows with skeleton-like appearance
+- [x] Ghost rows use varying widths for visual variety
+
 ---
 
 ## 🧩 P2 — Polish & Advanced Features

packages/components/src/renderers/complex/data-table.tsx

@@ -53,6 +53,16 @@ import {
 
 type SortDirection = 'asc' | 'desc' | null;
 
+/** Number of skeleton rows shown when the table has no data */
+const GHOST_ROW_COUNT = 3;
+
+/** Returns a Tailwind width class for ghost cell placeholders to create visual variety */
+function ghostCellWidth(columnIndex: number, totalColumns: number): string {
+  if (columnIndex === 0) return 'w-3/4';
+  if (columnIndex === totalColumns - 1) return 'w-1/3';
+  return 'w-1/2';
+}
+
 // Default English fallback translations for the data table
 const TABLE_DEFAULT_TRANSLATIONS: Record<string, string> = {
   'table.rowsPerPage': 'Rows per page',
@@ -147,6 +157,8 @@ const DataTableRenderer = ({ schema }: { schema: DataTableSchema }) => {
     resizableColumns = true,
     reorderableColumns = true,
     editable = false,
+    singleClickEdit = false,
+    selectionStyle = 'always',
     rowClassName,
     rowStyle,
     className,
@@ -171,6 +183,31 @@ const DataTableRenderer = ({ schema }: { schema: DataTableSchema }) => {
     }));
   }, [rawColumns]);
 
+  // Auto-size columns: estimate width from header and data content for columns without explicit widths
+  const autoSizedWidths = useMemo(() => {
+    const widths: Record<string, number> = {};
+    const cols = rawColumns.map((col: any) => ({
+      header: col.header || col.label,
+      accessorKey: col.accessorKey || col.name,
+      width: col.width,
+    }));
+    for (const col of cols) {
+      if (col.width) continue; // Skip columns with explicit widths
+      const headerLen = (col.header || '').length;
+      let maxLen = headerLen;
+      // Sample up to 50 rows for content width estimation
+      const sampleRows = data.slice(0, 50);
+      for (const row of sampleRows) {
+        const val = row[col.accessorKey];
+        const len = val != null ? String(val).length : 0;
+        if (len > maxLen) maxLen = len;
+      }
+      // Estimate pixel width: ~8px per character + 48px padding, min 80, max 400
+      widths[col.accessorKey] = Math.min(400, Math.max(80, maxLen * 8 + 48));
+    }
+    return widths;
+  }, [rawColumns, data]);
+
   // State management
   const [searchQuery, setSearchQuery] = useState('');
   const [sortColumn, setSortColumn] = useState<string | null>(null);
@@ -693,14 +730,14 @@ const DataTableRenderer = ({ schema }: { schema: DataTableSchema }) => {
                 </TableHead>
               )}
               {columns.map((col, index) => {
-                const columnWidth = columnWidths[col.accessorKey] || col.width;
+                const columnWidth = columnWidths[col.accessorKey] || col.width || autoSizedWidths[col.accessorKey];
                 const isDragging = draggedColumn === index;
                 const isDragOver = dragOverColumn === index;
                 const isFrozen = frozenColumns > 0 && index < frozenColumns;
                 const frozenOffset = isFrozen
                   ? columns.slice(0, index).reduce((sum, c, i) => {
                       if (i < frozenColumns) {
-                        const w = columnWidths[c.accessorKey] || c.width;
+                        const w = columnWidths[c.accessorKey] || c.width || autoSizedWidths[c.accessorKey];
                         return sum + (typeof w === 'number' ? w : w ? parseInt(String(w), 10) || 150 : 150);
                       }
                       return sum;
@@ -745,7 +782,7 @@ const DataTableRenderer = ({ schema }: { schema: DataTableSchema }) => {
                         {col.headerIcon && (
                           <span className="text-muted-foreground flex-shrink-0">{col.headerIcon}</span>
                         )}
-                        <span className="text-[11px] font-semibold uppercase tracking-wider text-muted-foreground/70">{col.header}</span>
+                        <span className="text-xs font-normal text-muted-foreground">{col.header}</span>
                         {sortable && col.sortable !== false && getSortIcon(col.accessorKey)}
                       </div>
                       {resizableColumns && col.resizable !== false && (
@@ -766,18 +803,33 @@ const DataTableRenderer = ({ schema }: { schema: DataTableSchema }) => {
           </TableHeader>
           <TableBody>
             {paginatedData.length === 0 ? (
-              <TableRow>
-                <TableCell
-                  colSpan={columns.length + (selectable ? 1 : 0) + (showRowNumbers ? 1 : 0) + (rowActions ? 1 : 0)}
-                  className="h-96 text-center text-muted-foreground"
-                >
-                  <div className="flex flex-col items-center justify-center gap-2">
-                    <Search className="h-8 w-8 text-muted-foreground/50" />
-                    <p>No results found</p>
-                    <p className="text-xs text-muted-foreground/50">Try adjusting your filters or search query.</p>
-                  </div>
-                </TableCell>
-              </TableRow>
+              <>
+                <TableRow>
+                  <TableCell
+                    colSpan={columns.length + (selectable ? 1 : 0) + (showRowNumbers ? 1 : 0) + (rowActions ? 1 : 0)}
+                    className="h-24 text-center text-muted-foreground"
+                  >
+                    <div className="flex flex-col items-center justify-center gap-2">
+                      <Search className="h-8 w-8 text-muted-foreground/50" />
+                      <p>No results found</p>
+                      <p className="text-xs text-muted-foreground/50">Try adjusting your filters or search query.</p>
+                    </div>
+                  </TableCell>
+                </TableRow>
+                {/* Ghost placeholder rows – visual skeleton to maintain table height when empty */}
+                {Array.from({ length: GHOST_ROW_COUNT }).map((_, i) => (
+                  <TableRow key={`ghost-${i}`} className="hover:bg-transparent opacity-[0.15] pointer-events-none" data-testid="ghost-row">
+                    {selectable && <TableCell className="p-3"><div className="h-4 w-4 rounded border border-muted-foreground/30" /></TableCell>}
+                    {showRowNumbers && <TableCell className="text-center p-3"><div className="h-3 w-6 mx-auto rounded bg-muted-foreground/30" /></TableCell>}
+                    {columns.map((_col, ci) => (
+                      <TableCell key={ci} className="p-3">
+                        <div className={cn("h-3 rounded bg-muted-foreground/30", ghostCellWidth(ci, columns.length))} />
+                      </TableCell>
+                    ))}
+                    {rowActions && <TableCell className="p-3"><div className="h-3 w-8 rounded bg-muted-foreground/30" /></TableCell>}
+                  </TableRow>
+                ))}
+              </>
             ) : (
               <>
                 {paginatedData.map((row, rowIndex) => {
@@ -810,11 +862,20 @@ const DataTableRenderer = ({ schema }: { schema: DataTableSchema }) => {
                       }}
                     >
                       {selectable && (
-                        <TableCell className={cn(frozenColumns > 0 && "sticky left-0 z-10 bg-background")}>
-                          <Checkbox
-                            checked={isSelected}
-                            onCheckedChange={(checked) => handleSelectRow(rowId, checked as boolean)}
-                          />
+                        <TableCell className={cn(frozenColumns > 0 && "sticky left-0 z-10 bg-background", selectionStyle === 'hover' && "relative")}>
+                          {selectionStyle === 'hover' ? (
+                            <div className={cn("transition-opacity", isSelected ? "opacity-100" : "opacity-0 group-hover/row:opacity-100")}>
+                              <Checkbox
+                                checked={isSelected}
+                                onCheckedChange={(checked) => handleSelectRow(rowId, checked as boolean)}
+                              />
+                            </div>
+                          ) : (
+                            <Checkbox
+                              checked={isSelected}
+                              onCheckedChange={(checked) => handleSelectRow(rowId, checked as boolean)}
+                            />
+                          )}
                         </TableCell>
                       )}
                       {showRowNumbers && (
@@ -833,21 +894,22 @@ const DataTableRenderer = ({ schema }: { schema: DataTableSchema }) => {
                           ) : schema.onRowClick && (
                             <button
                               type="button"
-                              className="absolute inset-0 hidden group-hover/row:flex items-center justify-center text-muted-foreground hover:text-primary"
+                              className="absolute inset-0 hidden group-hover/row:flex items-center justify-center gap-0.5 text-xs font-medium text-primary hover:text-primary/80"
                               data-testid="row-expand-button"
                               onClick={(e) => {
                                 e.stopPropagation();
                                 schema.onRowClick?.(row);
                               }}
                               title="Open record"
                             >
-                              <Expand className="h-3.5 w-3.5" />
+                              <span>Open</span>
+                              <ChevronRight className="h-3 w-3" />
                             </button>
                           )}
                         </TableCell>
                       )}
                       {columns.map((col, colIndex) => {
-                        const columnWidth = columnWidths[col.accessorKey] || col.width;
+                        const columnWidth = columnWidths[col.accessorKey] || col.width || autoSizedWidths[col.accessorKey];
                         const originalValue = row[col.accessorKey];
                         const hasPendingChange = rowChanges[col.accessorKey] !== undefined;
                         const cellValue = hasPendingChange ? rowChanges[col.accessorKey] : originalValue;
@@ -857,7 +919,7 @@ const DataTableRenderer = ({ schema }: { schema: DataTableSchema }) => {
                         const frozenOffset = isFrozen
                           ? columns.slice(0, colIndex).reduce((sum, c, i) => {
                               if (i < frozenColumns) {
-                                const w = columnWidths[c.accessorKey] || c.width;
+                                const w = columnWidths[c.accessorKey] || c.width || autoSizedWidths[c.accessorKey];
                                 return sum + (typeof w === 'number' ? w : w ? parseInt(String(w), 10) || 150 : 150);
                               }
                               return sum;
@@ -882,7 +944,8 @@ const DataTableRenderer = ({ schema }: { schema: DataTableSchema }) => {
                               maxWidth: columnWidth,
                               ...(isFrozen && { left: frozenOffset }),
                             }}
-                            onDoubleClick={() => isEditable && startEdit(rowIndex, col.accessorKey)}
+                            onDoubleClick={() => isEditable && !singleClickEdit && startEdit(rowIndex, col.accessorKey)}
+                            onClick={() => isEditable && singleClickEdit && startEdit(rowIndex, col.accessorKey)}
                             onKeyDown={(e) => handleCellKeyDown(e, rowIndex, col.accessorKey)}
                             tabIndex={0}
                           >

packages/fields/src/index.tsx

@@ -163,8 +163,8 @@ export function formatDate(value: string | Date, style?: string): string {
     return formatRelativeDate(date);
   }
 
-  // Default format: MMM DD, YYYY
-  return date.toLocaleDateString('en-US', {
+  // Default format: locale-aware human-readable (e.g. "Jan 15, 2024" or "2024/1/15")
+  return date.toLocaleDateString(undefined, {
     year: 'numeric',
     month: 'short',
     day: 'numeric',
@@ -179,7 +179,7 @@ export function formatDateTime(value: string | Date): string {
   const date = typeof value === 'string' ? new Date(value) : value;
   if (isNaN(date.getTime())) return '-';
 
-  return date.toLocaleDateString('en-US', {
+  return date.toLocaleDateString(undefined, {
     year: 'numeric',
     month: 'short',
     day: 'numeric',
@@ -334,12 +334,12 @@ export function DateTimeCellRenderer({ value }: CellRendererProps): React.ReactE
   const date = typeof value === 'string' ? new Date(value) : value;
   if (isNaN(date.getTime())) return <span className="text-muted-foreground">-</span>;
 
-  const datePart = date.toLocaleDateString('en-US', {
+  const datePart = date.toLocaleDateString(undefined, {
     month: 'numeric',
     day: 'numeric',
     year: 'numeric',
   });
-  const timePart = date.toLocaleTimeString('en-US', {
+  const timePart = date.toLocaleTimeString(undefined, {
     hour: 'numeric',
     minute: '2-digit',
     hour12: true,

packages/plugin-grid/src/ObjectGrid.tsx

@@ -182,7 +182,7 @@ export const ObjectGrid: React.FC<ObjectGridProps> = ({
   const [useCardView, setUseCardView] = useState(false);
   const [refreshKey, setRefreshKey] = useState(0);
   const [showExport, setShowExport] = useState(false);
-  const [rowHeightMode, setRowHeightMode] = useState<'compact' | 'short' | 'medium' | 'tall' | 'extra_tall'>(schema.rowHeight ?? 'medium');
+  const [rowHeightMode, setRowHeightMode] = useState<'compact' | 'short' | 'medium' | 'tall' | 'extra_tall'>(schema.rowHeight ?? 'compact');
   const [selectedRows, setSelectedRows] = useState<any[]>([]);
 
   // Column state persistence (order and widths)
@@ -971,6 +971,7 @@ export const ObjectGrid: React.FC<ObjectGridProps> = ({
     resizableColumns: schema.resizable ?? schema.resizableColumns ?? true,
     reorderableColumns: schema.reorderableColumns ?? false,
     editable: schema.editable ?? false,
+    singleClickEdit: schema.singleClickEdit ?? true,
     className: schema.className,
     cellClassName: rowHeightMode === 'compact'
       ? 'px-3 py-1 text-[13px] leading-tight'

packages/plugin-list/src/ListView.tsx

@@ -469,7 +469,7 @@ export const ListView: React.FC<ListViewProps> = ({
       };
       return map[schema.rowHeight] || 'comfortable';
     }
-    return 'comfortable';
+    return 'compact';
   }, [schema.densityMode, schema.rowHeight]);
   const density = useDensityMode(resolvedDensity);
 
@@ -1312,7 +1312,7 @@ export const ListView: React.FC<ListViewProps> = ({
             size="sm"
             className={cn(
               "h-7 px-2 text-muted-foreground hover:text-primary text-xs hidden lg:flex transition-colors duration-150",
-              density.mode !== 'comfortable' && "bg-primary/10 border border-primary/20 text-primary"
+              density.mode !== 'compact' && "bg-primary/10 border border-primary/20 text-primary"
             )}
             onClick={density.cycle}
             title={`Density: ${density.mode}`}

packages/plugin-list/src/UserFilters.tsx

@@ -205,7 +205,7 @@ function DropdownFilters({ fields, objectDef, data, onFilterChange, maxVisible,
           <button
             data-testid={`filter-badge-${f.field}`}
             className={cn(
-              'inline-flex items-center gap-1 rounded-md border h-7 px-2.5 text-xs font-medium transition-colors shrink-0',
+              'inline-flex items-center gap-1 rounded-full border h-7 px-2.5 text-xs font-medium transition-colors shrink-0',
               hasSelection
                 ? 'border-primary/30 bg-primary/5 text-primary'
                 : 'border-border bg-background hover:bg-accent text-foreground',
@@ -285,7 +285,7 @@ function DropdownFilters({ fields, objectDef, data, onFilterChange, maxVisible,
               <PopoverTrigger asChild>
                 <button
                   data-testid="user-filters-more"
-                  className="inline-flex items-center gap-1 rounded-md border border-border bg-background hover:bg-accent text-foreground h-7 px-2.5 text-xs font-medium transition-colors shrink-0"
+                  className="inline-flex items-center gap-1 rounded-full border border-border bg-background hover:bg-accent text-foreground h-7 px-2.5 text-xs font-medium transition-colors shrink-0"
                 >
                   <span>More</span>
                   <span className="flex h-4 min-w-[16px] items-center justify-center rounded-full bg-muted text-[10px] font-medium">

packages/plugin-list/src/__tests__/ListView.test.tsx

@@ -300,8 +300,8 @@ describe('ListView', () => {
 
     renderWithProvider(<ListView schema={schema} />);
 
-    // Default density mode is 'comfortable'
-    const densityButton = screen.getByTitle('Density: comfortable');
+    // Default density mode is 'compact'
+    const densityButton = screen.getByTitle('Density: compact');
     expect(densityButton).toBeInTheDocument();
   });
 

packages/types/src/data-display.ts

@@ -341,6 +341,13 @@ export interface DataTableSchema extends BaseSchema {
    * @default false
    */
   selectable?: boolean | 'single' | 'multiple';
+  /**
+   * Selection checkbox display style
+   * - 'always': Checkboxes are always visible
+   * - 'hover': Checkboxes only appear on row hover
+   * @default 'always'
+   */
+  selectionStyle?: 'always' | 'hover';
   /**
    * Enable column sorting
    * @default true
@@ -388,6 +395,12 @@ export interface DataTableSchema extends BaseSchema {
    * @default false
    */
   editable?: boolean;
+  /**
+   * Enable single-click editing mode
+   * When true with editable, clicking a cell enters edit mode (instead of double-click)
+   * @default false
+   */
+  singleClickEdit?: boolean;
   /**
    * Cell value change handler
    * Called when a cell value is edited