[Lens] Provide single-value functions to show the "Last" value of some field

x-pack/plugins/lens/public/editor_frame_service/editor_frame/workspace_panel/warnings_popover.scss

@@ -0,0 +1,17 @@
+.lnsWorkspaceWarning__button {
+  color: $euiColorWarningText;
+}
+
+.lnsWorkspaceWarningList {
+  @include euiYScroll;
+  max-height: $euiSize * 20;
+  width: $euiSize * 16;
+}
+
+.lnsWorkspaceWarningList__item {
+  padding: $euiSize;
+
+  & + & {
+    border-top: $euiBorderThin;
+  }
+}

x-pack/plugins/lens/public/editor_frame_service/editor_frame/workspace_panel/warnings_popover.tsx

@@ -0,0 +1,57 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License;
+ * you may not use this file except in compliance with the Elastic License.
+ */
+
+import './workspace_panel_wrapper.scss';
+import './warnings_popover.scss';
+
+import React, { useState } from 'react';
+import { i18n } from '@kbn/i18n';
+import { EuiPopover, EuiText, EuiButtonEmpty } from '@elastic/eui';
+
+export const WarningsPopover = ({
+  children,
+}: {
+  children?: React.ReactNode | React.ReactNode[];
+}) => {
+  const [isPopoverOpen, setIsPopoverOpen] = useState(false);
+
+  if (!children) {
+    return null;
+  }
+
+  const onButtonClick = () => setIsPopoverOpen((isOpen) => !isOpen);
+  const closePopover = () => setIsPopoverOpen(false);
+  const warningsCount = React.Children.count(children);
+  return (
+    <EuiPopover
+      panelPaddingSize="none"
+      button={
+        <EuiButtonEmpty
+          onClick={onButtonClick}
+          iconType="alert"
+          className="lnsWorkspaceWarning__button"
+        >
+          {i18n.translate('xpack.lens.chartWarnings.number', {
+            defaultMessage: `{warningsCount} {warningsCount, plural, one {warning} other {warnings}}`,
+            values: {
+              warningsCount,
+            },
+          })}
+        </EuiButtonEmpty>
+      }
+      isOpen={isPopoverOpen}
+      closePopover={closePopover}
+    >
+      <ul className="lnsWorkspaceWarningList">
+        {React.Children.map(children, (child, index) => (
+          <li key={index} className="lnsWorkspaceWarningList__item">
+            <EuiText size="s">{child}</EuiText>
+          </li>
+        ))}
+      </ul>
+    </EuiPopover>
+  );
+};

x-pack/plugins/lens/public/editor_frame_service/editor_frame/workspace_panel/workspace_panel_wrapper.tsx

@@ -19,6 +19,7 @@ import { Datasource, FramePublicAPI, Visualization } from '../../../types';
 import { NativeRenderer } from '../../../native_renderer';
 import { Action } from '../state_management';
 import { ChartSwitch } from './chart_switch';
+import { WarningsPopover } from './warnings_popover';
 
 export interface WorkspacePanelWrapperProps {
   children: React.ReactNode | React.ReactNode[];
@@ -64,40 +65,59 @@ export function WorkspacePanelWrapper({
     },
     [dispatch, activeVisualization]
   );
+  const warningMessages =
+    activeVisualization?.getWarningMessages &&
+    activeVisualization.getWarningMessages(visualizationState, framePublicAPI);
   return (
     <>
       <div>
         <EuiFlexGroup
+          alignItems="center"
           gutterSize="m"
           direction="row"
           responsive={false}
           wrap={true}
-          className="lnsWorkspacePanelWrapper__toolbar"
+          justifyContent="spaceBetween"
         >
           <EuiFlexItem grow={false}>
-            <ChartSwitch
-              data-test-subj="lnsChartSwitcher"
-              visualizationMap={visualizationMap}
-              visualizationId={visualizationId}
-              visualizationState={visualizationState}
-              datasourceMap={datasourceMap}
-              datasourceStates={datasourceStates}
-              dispatch={dispatch}
-              framePublicAPI={framePublicAPI}
-            />
+            <EuiFlexGroup
+              gutterSize="m"
+              direction="row"
+              responsive={false}
+              wrap={true}
+              className="lnsWorkspacePanelWrapper__toolbar"
+            >
+              <EuiFlexItem grow={false}>
+                <ChartSwitch
+                  data-test-subj="lnsChartSwitcher"
+                  visualizationMap={visualizationMap}
+                  visualizationId={visualizationId}
+                  visualizationState={visualizationState}
+                  datasourceMap={datasourceMap}
+                  datasourceStates={datasourceStates}
+                  dispatch={dispatch}
+                  framePublicAPI={framePublicAPI}
+                />
+              </EuiFlexItem>
+              {activeVisualization && activeVisualization.renderToolbar && (
+                <EuiFlexItem grow={false}>
+                  <NativeRenderer
+                    render={activeVisualization.renderToolbar}
+                    nativeProps={{
+                      frame: framePublicAPI,
+                      state: visualizationState,
+                      setState: setVisualizationState,
+                    }}
+                  />
+                </EuiFlexItem>
+              )}
+            </EuiFlexGroup>
+          </EuiFlexItem>
+          <EuiFlexItem grow={false}>
+            {warningMessages && warningMessages.length ? (
+              <WarningsPopover>{warningMessages}</WarningsPopover>
+            ) : null}
           </EuiFlexItem>
-          {activeVisualization && activeVisualization.renderToolbar && (
-            <EuiFlexItem grow={false}>
-              <NativeRenderer
-                render={activeVisualization.renderToolbar}
-                nativeProps={{
-                  frame: framePublicAPI,
-                  state: visualizationState,
-                  setState: setVisualizationState,
-                }}
-              />
-            </EuiFlexItem>
-          )}
         </EuiFlexGroup>
       </div>
       <EuiPageContent className="lnsWorkspacePanelWrapper">

x-pack/plugins/lens/public/indexpattern_datasource/dimension_panel/dimension_editor.scss

@@ -15,6 +15,10 @@
   column-gap: $euiSizeXL;
 }
 
+.lnsIndexPatternDimensionEditor__operation .euiListGroupItem__label {
+  width: 100%;
+}
+
 .lnsIndexPatternDimensionEditor__operation > button {
   padding-top: 0;
   padding-bottom: 0;

x-pack/plugins/lens/public/indexpattern_datasource/dimension_panel/dimension_editor.tsx

@@ -15,6 +15,7 @@ import {
   EuiSpacer,
   EuiListGroupItemProps,
   EuiFormLabel,
+  EuiToolTip,
 } from '@elastic/eui';
 import { IndexPatternDimensionEditorProps } from './dimension_panel';
 import { OperationSupportMatrix } from './operation_support';
@@ -141,20 +142,19 @@ export function DimensionEditor(props: DimensionEditorProps) {
           definition.input === 'field' &&
           fieldByOperation[operationType]?.has(selectedColumn.sourceField)) ||
         (selectedColumn && !hasField(selectedColumn) && definition.input === 'none'),
+      disabledStatus:
+        definition.getDisabledStatus &&
+        definition.getDisabledStatus(state.indexPatterns[state.currentIndexPatternId]),
     };
   });
 
-  const selectedColumnSourceField =
-    selectedColumn && 'sourceField' in selectedColumn ? selectedColumn.sourceField : undefined;
-
-  const currentFieldIsInvalid = useMemo(
-    () =>
-      fieldIsInvalid(selectedColumnSourceField, selectedColumn?.operationType, currentIndexPattern),
-    [selectedColumnSourceField, selectedColumn?.operationType, currentIndexPattern]
-  );
+  const currentFieldIsInvalid = useMemo(() => fieldIsInvalid(selectedColumn, currentIndexPattern), [
+    selectedColumn,
+    currentIndexPattern,
+  ]);
 
   const sideNavItems: EuiListGroupItemProps[] = operationsWithCompatibility.map(
-    ({ operationType, compatibleWithCurrentField }) => {
+    ({ operationType, compatibleWithCurrentField, disabledStatus }) => {
       const isActive = Boolean(
         incompleteOperation === operationType ||
           (!incompleteOperation && selectedColumn && selectedColumn.operationType === operationType)
@@ -168,7 +168,13 @@ export function DimensionEditor(props: DimensionEditorProps) {
       }
 
       let label: EuiListGroupItemProps['label'] = operationPanels[operationType].displayName;
-      if (isActive) {
+      if (disabledStatus) {
+        label = (
+          <EuiToolTip content={disabledStatus} display="block" position="left">
+            <span>{operationPanels[operationType].displayName}</span>
+          </EuiToolTip>
+        );
+      } else if (isActive) {
         label = <strong>{operationPanels[operationType].displayName}</strong>;
       }
 
@@ -178,6 +184,7 @@ export function DimensionEditor(props: DimensionEditorProps) {
         color,
         isActive,
         size: 's',
+        isDisabled: !!disabledStatus,
         className: 'lnsIndexPatternDimensionEditor__operation',
         'data-test-subj': `lns-indexPatternDimension-${operationType}${
           compatibleWithCurrentField ? '' : ' incompatible'
@@ -264,7 +271,6 @@ export function DimensionEditor(props: DimensionEditorProps) {
               ? currentIndexPattern.getFieldByName(selectedColumn.sourceField)
               : undefined,
           });
-
           setState(mergeLayer({ state, layerId, newLayer }));
         },
       };

x-pack/plugins/lens/public/indexpattern_datasource/dimension_panel/dimension_panel.test.tsx

@@ -1242,12 +1242,12 @@ describe('IndexPatternDimensionEditorPanel', () => {
     expect(items.map(({ label }: { label: React.ReactNode }) => label)).toEqual([
       'Average',
       'Count',
+      'Last value',
       'Maximum',
       'Median',
       'Minimum',
       'Sum',
       'Unique count',
-      '\u00a0',
     ]);
   });
 

x-pack/plugins/lens/public/indexpattern_datasource/dimension_panel/dimension_panel.tsx

@@ -12,7 +12,7 @@ import { IStorageWrapper } from 'src/plugins/kibana_utils/public';
 import { DatasourceDimensionTriggerProps, DatasourceDimensionEditorProps } from '../../types';
 import { DataPublicPluginStart } from '../../../../../../src/plugins/data/public';
 import { IndexPatternColumn } from '../indexpattern';
-import { fieldIsInvalid } from '../utils';
+import { isColumnInvalid } from '../utils';
 import { IndexPatternPrivateState } from '../types';
 import { DimensionEditor } from './dimension_editor';
 import { DateRange } from '../../../common';
@@ -45,24 +45,22 @@ export const IndexPatternDimensionTriggerComponent = function IndexPatternDimens
 ) {
   const layerId = props.layerId;
   const layer = props.state.layers[layerId];
-  const selectedColumn: IndexPatternColumn | null = layer.columns[props.columnId] || null;
   const currentIndexPattern = props.state.indexPatterns[layer.indexPatternId];
+  const { columnId, uniqueLabel } = props;
 
-  const selectedColumnSourceField =
-    selectedColumn && 'sourceField' in selectedColumn ? selectedColumn.sourceField : undefined;
-  const currentFieldIsInvalid = useMemo(
-    () =>
-      fieldIsInvalid(selectedColumnSourceField, selectedColumn?.operationType, currentIndexPattern),
-    [selectedColumnSourceField, selectedColumn?.operationType, currentIndexPattern]
+  const currentColumnHasErrors = useMemo(
+    () => isColumnInvalid(layer, columnId, currentIndexPattern),
+    [layer, columnId, currentIndexPattern]
   );
 
-  const { columnId, uniqueLabel } = props;
+  const selectedColumn: IndexPatternColumn | null = layer.columns[props.columnId] || null;
+
   if (!selectedColumn) {
     return null;
   }
   const formattedLabel = wrapOnDot(uniqueLabel);
 
-  if (currentFieldIsInvalid) {
+  if (currentColumnHasErrors) {
     return (
       <EuiToolTip
         content={

x-pack/plugins/lens/public/indexpattern_datasource/dimension_panel/droppable.test.ts

@@ -17,8 +17,6 @@ import { OperationMetadata } from '../../types';
 import { IndexPatternColumn } from '../operations';
 import { getFieldByNameFactory } from '../pure_helpers';
 
-jest.mock('../operations');
-
 const fields = [
   {
     name: 'timestamp',

x-pack/plugins/lens/public/indexpattern_datasource/indexpattern.test.ts

@@ -819,7 +819,7 @@ describe('IndexPattern Data Source', () => {
       expect(messages).toHaveLength(1);
       expect(messages![0]).toEqual({
         shortMessage: 'Invalid reference.',
-        longMessage: 'Field "bytes" has an invalid reference.',
+        longMessage: '"Foo" has an invalid reference.',
       });
     });
 
@@ -844,7 +844,7 @@ describe('IndexPattern Data Source', () => {
               col2: {
                 dataType: 'number',
                 isBucketed: false,
-                label: 'Foo',
+                label: 'Foo2',
                 operationType: 'count', // <= invalid
                 sourceField: 'memory',
               },
@@ -857,7 +857,7 @@ describe('IndexPattern Data Source', () => {
       expect(messages).toHaveLength(1);
       expect(messages![0]).toEqual({
         shortMessage: 'Invalid references.',
-        longMessage: 'Fields "bytes", "memory" have invalid reference.',
+        longMessage: '"Foo", "Foo2" have invalid reference.',
       });
     });
 
@@ -882,7 +882,7 @@ describe('IndexPattern Data Source', () => {
               col2: {
                 dataType: 'number',
                 isBucketed: false,
-                label: 'Foo',
+                label: 'Foo2',
                 operationType: 'count', // <= invalid
                 sourceField: 'memory',
               },
@@ -909,11 +909,11 @@ describe('IndexPattern Data Source', () => {
       expect(messages).toEqual([
         {
           shortMessage: 'Invalid references on Layer 1.',
-          longMessage: 'Layer 1 has invalid references in fields "bytes", "memory".',
+          longMessage: 'Layer 1 has invalid references in "Foo", "Foo2".',
         },
         {
           shortMessage: 'Invalid reference on Layer 2.',
-          longMessage: 'Layer 2 has an invalid reference in field "source".',
+          longMessage: 'Layer 2 has an invalid reference in "Foo".',
         },
       ]);
     });