Replace AG Grid pivot with Perspective viewer in Forecast view

- Swap AG Grid CSS/JS for Perspective CDN imports (4.4.0)
- Replace #pivot-grid div with <perspective-viewer> web component
- Add loadPerspective() singleton, initPerspectiveViewer(data)
- Build default layout from col_meta (dims → group_by, date → split_by)
- Extract slice from perspective-click event.detail.config.filter
  (only == filters on role=dimension columns feed the operation panel)
- table.update() appends operation result rows without full reload
- Save/reset layout buttons per version in localStorage
- Remove expand/collapse buttons (Perspective handles natively)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

public/app.js

@@ -16,9 +16,10 @@ const state = {
         sources:  null,
         colMeta:  null,
         versions: null,
-        pivot:    null,
         log:      null
-    }
+    },
+    pspWorker:  null,   // Perspective worker
+    pspTable:   null,   // Perspective table
 };
 
 /* ============================================================
@@ -713,7 +714,7 @@ async function loadForecastData() {
         showStatus('Loading forecast data...', 'info');
         const rawData = await api('GET', `/versions/${state.version.id}/data`);
         const data = parseNumericRows(rawData);
-        initPivotGrid(data);
+        await initPerspectiveViewer(data);
         showStatus(`Loaded ${data.length.toLocaleString()} rows`, 'success');
     } catch (err) {
         showStatus(err.message, 'error');
@@ -721,125 +722,100 @@ async function loadForecastData() {
 }
 
 /* ============================================================
-   FORECAST VIEW — pivot grid
+   FORECAST VIEW — Perspective pivot
    ============================================================ */
-function buildPivotColDefs() {
+let _perspectivePromise = null;
-    const defs = [];
+function loadPerspective() {
+    if (_perspectivePromise) return _perspectivePromise;
+    _perspectivePromise = (async () => {
+        const [{ default: perspective }] = await Promise.all([
+            import('https://cdn.jsdelivr.net/npm/@perspective-dev/client@4.4.0/dist/cdn/perspective.js'),
+            import('https://cdn.jsdelivr.net/npm/@perspective-dev/viewer@4.4.0/dist/cdn/perspective-viewer.js'),
+            import('https://cdn.jsdelivr.net/npm/@perspective-dev/viewer-datagrid@4.4.0/dist/cdn/perspective-viewer-datagrid.js'),
+            import('https://cdn.jsdelivr.net/npm/@perspective-dev/viewer-d3fc@4.4.0/dist/cdn/perspective-viewer-d3fc.js'),
+        ]);
+        return perspective;
+    })();
+    return _perspectivePromise;
+}
 
-    state.colMeta.forEach((c) => {
+function pspLayoutKey() {
-        if (c.role === 'ignore') return;
+    return `psp_layout_pf_${state.version?.id}`;
-        const needsGetter = /\W/.test(c.cname);
+}
-        const def = {
+
-            field:       c.cname,
+function buildDefaultLayout() {
-            headerName:  c.label || c.cname,
+    const dims   = state.colMeta.filter(c => c.role === 'dimension').map(c => c.cname);
-            resizable:   true,
+    const values = state.colMeta.filter(c => c.role === 'value' || c.role === 'units').map(c => c.cname);
-            sortable:    true,
+    const date   = state.colMeta.find(c => c.role === 'date')?.cname;
-            ...(needsGetter ? { valueGetter: p => p.data ? p.data[c.cname] : undefined } : {})
+    return {
+        group_by:  dims.slice(0, 2),           // first two dimensions as row groups
+        split_by:  date ? [date] : [],          // date as column pivot
+        columns:   values,
+        settings:  true,
+        plugin_config: { edit_mode: 'SELECT_ROW' }
     };
-        if (c.role === 'dimension' || c.role === 'date') {
-            def.enableRowGroup = true;
-            def.enablePivot    = true;
 }
-        if (c.role === 'value' || c.role === 'units') {
-            def.enableValue    = true;
-            def.aggFunc        = 'sum';
-            def.type           = 'numericColumn';
-            def.valueFormatter = p => p.value != null
-                ? Number(p.value).toLocaleString(undefined, { maximumFractionDigits: 2 })
-                : '';
-        }
-        defs.push(def);
 
-        if (c.role === 'date') {
+async function initPerspectiveViewer(data) {
-            defs.push({
+    const viewer = document.getElementById('pivot-viewer');
-                colId:       c.cname + '__month',
+
-                headerName:  (c.label || c.cname) + ' (Month)',
+    // terminate old worker if reloading
-                enableRowGroup: true,
+    if (state.pspWorker) {
-                enablePivot:    true,
+        try { state.pspWorker.terminate(); } catch (_) {}
-                valueGetter: p => {
+        state.pspWorker = null;
-                    const v = p.data ? p.data[c.cname] : undefined;
+        state.pspTable  = null;
-                    if (!v) return undefined;
-                    const d = new Date(v);
-                    return isNaN(d) ? undefined : `${d.getFullYear()}-${String(d.getMonth() + 1).padStart(2, '0')}`;
-                }
-            });
     }
+
+    const perspective = await loadPerspective();
+    const worker      = await perspective.worker();
+    state.pspWorker   = worker;
+
+    const table      = await worker.table(data, { name: `pf_${state.version.id}` });
+    state.pspTable   = table;
+
+    // remove old listener to avoid stacking on refresh
+    const fresh = viewer.cloneNode(false);
+    viewer.parentNode.replaceChild(fresh, viewer);
+    const v = document.getElementById('pivot-viewer');
+
+    v.addEventListener('perspective-click', async (e) => {
+        const detail       = e.detail || {};
+        const eventFilters = (detail.config || {}).filter || [];
+        const config       = await v.save();
+        extractSliceFromPerspective(eventFilters, config);
     });
 
-    // always include pf_iter for grouping context
+    await v.load(worker);
-    defs.push({ field: 'pf_iter', headerName: 'Iter', enableRowGroup: true, enablePivot: true, width: 90 });
-    defs.push({ field: 'pf_user',       headerName: 'User',    width: 90, hide: true });
-    defs.push({ field: 'pf_created_at', headerName: 'Created', width: 130, hide: true,
-        valueFormatter: p => p.value ? new Date(p.value).toLocaleDateString() : '' });
 
-    return defs;
+    const saved = localStorage.getItem(pspLayoutKey());
+    if (saved) {
+        await v.restore(JSON.parse(saved));
+    } else {
+        await v.restore(buildDefaultLayout());
     }
 
-function initPivotGrid(data) {
+    // update reset button visibility
-    const el = document.getElementById('pivot-grid');
+    document.getElementById('btn-reset-layout')
-
+        .classList.toggle('hidden', !localStorage.getItem(pspLayoutKey()));
-    if (state.grids.pivot) {
-        state.grids.pivot.setGridOption('rowData', data);
-        return;
-    }
-
-    state.grids.pivot = agGrid.createGrid(el, {
-        columnDefs:           buildPivotColDefs(),
-        rowData:              data,
-        rowSelection:         'single',
-        groupDisplayType:     'singleColumn',
-        rowGroupPanelShow:    'always',
-        groupDefaultExpanded: 1,
-        suppressAggFuncInHeader: true,
-        animateRows:          true,
-        sideBar: {
-            toolPanels: [{
-                id:             'columns',
-                labelDefault:   'Columns',
-                labelKey:       'columns',
-                iconKey:        'columns',
-                toolPanel:      'agColumnsToolPanel',
-                toolPanelParams: {}
-            }],
-            defaultToolPanel: 'columns'
-        },
-        defaultColDef:        { resizable: true, sortable: true },
-        autoGroupColumnDef:   {
-            headerName:   'Group',
-            minWidth:     200,
-            cellRendererParams: { suppressCount: false }
-        },
-        headerHeight: 32,
-        rowHeight:    28,
-        onRowClicked: onPivotRowClicked
-    });
 }
 
 /* ============================================================
    FORECAST VIEW — slice selection
    ============================================================ */
-function onPivotRowClicked(event) {
+function extractSliceFromPerspective(eventFilters, config) {
-    const node  = event.node;
+    const dimFields = new Set(state.colMeta.filter(c => c.role === 'dimension').map(c => c.cname));
-    state.slice = extractSliceFromNode(node);
+    const slice = {};
+    for (const [field, op, value] of eventFilters) {
+        if (op === '==' && dimFields.has(field) && value != null && value !== '') {
+            slice[field] = String(value);
+        }
+    }
+    state.slice = slice;
     renderSliceDisplay();
-
-    // populate recode and clone fields whenever slice changes
     renderDimFields('recode');
     renderDimFields('clone');
 }
 
-function extractSliceFromNode(node) {
-    const slice   = {};
-    let current = node;
-    while (current) {
-        if (current.field && current.key != null && current.key !== '') {
-            slice[current.field] = current.key;
-        }
-        current = current.parent;
-    }
-    return slice;
-}
-
 function renderSliceDisplay() {
     const display = document.getElementById('slice-display');
     const hasSlice = Object.keys(state.slice).length > 0;
@@ -938,7 +914,7 @@ async function submitScale() {
         document.getElementById('scale-value-incr').value = '';
         document.getElementById('scale-units-incr').value = '';
         document.getElementById('scale-note').value = '';
-        state.grids.pivot.applyTransaction({ add: parseNumericRows(result.rows) });
+        if (state.pspTable) await state.pspTable.update(parseNumericRows(result.rows));
     } catch (err) {
         showStatus(err.message, 'error');
     }
@@ -964,7 +940,7 @@ async function submitRecode() {
         });
         showStatus(`Recode applied — ${result.rows_affected} rows inserted`, 'success');
         document.querySelectorAll('#recode-fields input[data-col], #recode-fields select[data-col]').forEach(i => { i.value = ''; });
-        state.grids.pivot.applyTransaction({ add: parseNumericRows(result.rows) });
+        if (state.pspTable) await state.pspTable.update(parseNumericRows(result.rows));
     } catch (err) {
         showStatus(err.message, 'error');
     }
@@ -993,7 +969,7 @@ async function submitClone() {
         showStatus(`Clone applied — ${result.rows_affected} rows inserted`, 'success');
         document.querySelectorAll('#clone-fields input[data-col], #clone-fields select[data-col]').forEach(i => { i.value = ''; });
         document.getElementById('clone-scale').value = '1';
-        state.grids.pivot.applyTransaction({ add: parseNumericRows(result.rows) });
+        if (state.pspTable) await state.pspTable.update(parseNumericRows(result.rows));
     } catch (err) {
         showStatus(err.message, 'error');
     }
@@ -1134,8 +1110,21 @@ document.addEventListener('DOMContentLoaded', () => {
 
     // forecast view buttons
     document.getElementById('btn-forecast-refresh').addEventListener('click', loadForecastData);
-    document.getElementById('btn-expand-all').addEventListener('click',   () => state.grids.pivot?.expandAll());
+    document.getElementById('btn-save-layout').addEventListener('click', async () => {
-    document.getElementById('btn-collapse-all').addEventListener('click', () => state.grids.pivot?.collapseAll());
+        const v = document.getElementById('pivot-viewer');
+        if (!v) return;
+        const layout = await v.save();
+        localStorage.setItem(pspLayoutKey(), JSON.stringify(layout));
+        document.getElementById('btn-reset-layout').classList.remove('hidden');
+        showStatus('Layout saved', 'success');
+    });
+    document.getElementById('btn-reset-layout').addEventListener('click', async () => {
+        const v = document.getElementById('pivot-viewer');
+        if (!v) return;
+        localStorage.removeItem(pspLayoutKey());
+        document.getElementById('btn-reset-layout').classList.add('hidden');
+        await v.restore(buildDefaultLayout());
+    });
     document.getElementById('btn-clear-slice').addEventListener('click', clearSlice);
 
     document.querySelectorAll('.op-tab').forEach(tab => {

public/index.html

@@ -4,8 +4,7 @@
     <meta charset="UTF-8">
     <meta name="viewport" content="width=device-width, initial-scale=1.0">
     <title>Pivot Forecast</title>
-    <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/ag-grid-community@31.0.0/styles/ag-grid.css">
+    <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/@perspective-dev/viewer/dist/css/themes.css" crossorigin="anonymous">
-    <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/ag-grid-community@31.0.0/styles/ag-theme-alpine.css">
     <link rel="stylesheet" href="styles.css">
 </head>
 <body>
@@ -163,12 +162,12 @@
             <div class="forecast-toolbar">
                 <span id="forecast-label">No version selected</span>
                 <button id="btn-forecast-refresh" class="btn">Refresh</button>
-                <button id="btn-expand-all" class="btn">Expand All</button>
+                <button id="btn-save-layout" class="btn">Save layout</button>
-                <button id="btn-collapse-all" class="btn">Collapse All</button>
+                <button id="btn-reset-layout" class="btn hidden">Reset layout</button>
             </div>
             <div class="forecast-layout">
                 <div id="pivot-panel">
-                    <div id="pivot-grid" class="ag-theme-alpine"></div>
+                    <perspective-viewer id="pivot-viewer" theme="Pro Light"></perspective-viewer>
                 </div>
                 <div id="operation-panel">
                     <div class="op-section">
@@ -283,7 +282,6 @@
     </div>
 </div>
 
-<script src="https://cdn.jsdelivr.net/npm/ag-grid-enterprise@31.0.0/dist/ag-grid-enterprise.min.js"></script>
 <script src="app.js"></script>
 </body>
 </html>

public/styles.css

@@ -199,7 +199,7 @@ body {
     box-shadow: 0 1px 3px rgba(0,0,0,.08);
     min-width: 0;
 }
-#pivot-grid { width: 100%; height: 100%; }
+#pivot-viewer { width: 100%; height: 100%; }
 
 #operation-panel {
     width: 270px;