[Discover] Add field types in-product help

packages/kbn-doc-links/src/get_doc_links.ts

@@ -67,6 +67,9 @@ export const getDocLinks = ({ kibanaBranch }: GetDocLinkOptions): DocLinks => {
     discover: {
       guide: `${KIBANA_DOCS}discover.html`,
       fieldStatistics: `${KIBANA_DOCS}show-field-statistics.html`,
+      fieldTypeHelp: `${ELASTICSEARCH_DOCS}mapping-types.html`,
+      dateFieldTypeDocs: `${ELASTICSEARCH_DOCS}date.html`,
+      dateFormatsDocs: `${ELASTICSEARCH_DOCS}mapping-date-format.html`,
       documentExplorer: `${KIBANA_DOCS}document-explorer.html`,
     },
     filebeat: {

src/plugins/discover/public/application/main/components/sidebar/discover_field_search.scss

@@ -2,6 +2,14 @@
   padding: $euiSizeM;
 }
 
-.dscFieldSearch__filterWrapper {
-  width: 100%;
+.dscFieldTypesHelp__popover {
+  flex-grow: 0;
+  min-width: 0 !important; // Reduce width of icon-only button
 }
+
+.dscFieldTypesHelp__panel {
+  width: $euiSize * 22;
+  @include euiBreakpoint('xs', 's') {
+    width: $euiSize * 20;
+  }
+}

src/plugins/discover/public/application/main/components/sidebar/discover_field_search.test.tsx

@@ -13,17 +13,25 @@ import { findTestSubject } from '@elastic/eui/lib/test';
 import { DiscoverFieldSearch, Props } from './discover_field_search';
 import { EuiButtonGroupProps, EuiPopover } from '@elastic/eui';
 import { ReactWrapper } from 'enzyme';
+import { KibanaContextProvider } from '../../../../../../kibana_react/public';
 
 describe('DiscoverFieldSearch', () => {
   const defaultProps = {
     onChange: jest.fn(),
     value: 'test',
     types: ['any', 'string', '_source'],
+    presentFieldTypes: ['string', 'date', 'boolean', 'number'],
   };
 
   function mountComponent(props?: Props) {
     const compProps = props || defaultProps;
-    return mountWithIntl(<DiscoverFieldSearch {...compProps} />);
+    return mountWithIntl(
+      <KibanaContextProvider
+        services={{ docLinks: { links: { discover: { fieldTypeHelp: '' } } } }}
+      >
+        <DiscoverFieldSearch {...compProps} />
+      </KibanaContextProvider>
+    );
   }
 
   function findButtonGroup(component: ReactWrapper, id: string) {
@@ -131,9 +139,25 @@ describe('DiscoverFieldSearch', () => {
     const btn = findTestSubject(component, 'toggleFieldFilterButton');
     btn.simulate('click');
     let popover = component.find(EuiPopover);
-    expect(popover.prop('isOpen')).toBe(true);
+    expect(popover.get(0).props.isOpen).toBe(true);
     btn.simulate('click');
     popover = component.find(EuiPopover);
-    expect(popover.prop('isOpen')).toBe(false);
+    expect(popover.get(0).props.isOpen).toBe(false);
+  });
+
+  test('click help button should open popover with types of field docs', () => {
+    const component = mountComponent();
+
+    const btn = findTestSubject(component, 'fieldTypesHelpButton');
+    btn.simulate('click');
+    let popover = component.find(EuiPopover);
+    expect(popover.get(1).props.isOpen).toBe(true);
+
+    const rows = component.find('.euiTableRow');
+    expect(rows.length).toBe(4);
+
+    btn.simulate('click');
+    popover = component.find(EuiPopover);
+    expect(popover.get(1).props.isOpen).toBe(false);
   });
 });

src/plugins/discover/public/application/main/components/sidebar/discover_field_search.tsx

@@ -8,9 +8,10 @@
 
 import './discover_field_search.scss';
 
-import React, { OptionHTMLAttributes, ReactNode, useState } from 'react';
+import React, { OptionHTMLAttributes, ReactNode, useMemo, useState } from 'react';
 import { i18n } from '@kbn/i18n';
 import {
+  EuiBasicTable,
   EuiFieldSearch,
   EuiFilterGroup,
   EuiFlexGroup,
@@ -24,11 +25,18 @@ import {
   EuiForm,
   EuiFormRow,
   EuiButtonGroup,
-  EuiOutsideClickDetector,
   EuiFilterButton,
   EuiSpacer,
+  EuiIcon,
+  EuiBasicTableColumn,
+  EuiLink,
+  EuiText,
+  EuiPanel,
 } from '@elastic/eui';
 import { FormattedMessage } from '@kbn/i18n-react';
+import { FieldIcon } from '@kbn/react-field';
+import { GetFieldTypeDescription } from './lib/get_field_type_description';
+import { useDiscoverServices } from '../../../../utils/use_discover_services';
 
 export interface State {
   searchable: string;
@@ -43,23 +51,31 @@ export interface Props {
    * triggered on input of user into search field
    */
   onChange: (field: string, value: string | boolean | undefined) => void;
-
+  /**
+   * types for the type filter
+   */
+  types: string[];
+  /**
+   * types presented in current data view
+   */
+  presentFieldTypes: string[];
   /**
    * the input value of the user
    */
   value?: string;
+}
 
-  /**
-   * types for the type filter
-   */
-  types: string[];
+interface FieldTypeTableItem {
+  id: number;
+  dataType: string;
+  description: string;
 }
 
 /**
  * Component is Discover's side bar to  search of available fields
  * Additionally there's a button displayed that allows the user to show/hide more filter fields
  */
-export function DiscoverFieldSearch({ onChange, value, types }: Props) {
+export function DiscoverFieldSearch({ onChange, value, types, presentFieldTypes }: Props) {
   const searchPlaceholder = i18n.translate('discover.fieldChooser.searchPlaceHolder', {
     defaultMessage: 'Search field names',
   });
@@ -80,13 +96,51 @@ export function DiscoverFieldSearch({ onChange, value, types }: Props) {
 
   const [activeFiltersCount, setActiveFiltersCount] = useState(0);
   const [isPopoverOpen, setPopoverOpen] = useState(false);
+  const [isHelpOpen, setIsHelpOpen] = useState(false);
   const [values, setValues] = useState<State>({
     searchable: 'any',
     aggregatable: 'any',
     type: 'any',
     missing: true,
   });
 
+  const { docLinks } = useDiscoverServices();
+
+  const items: FieldTypeTableItem[] = useMemo(() => {
+    return presentFieldTypes
+      .sort((one, another) => one.localeCompare(another))
+      .map((element, index) => ({
+        id: index,
+        dataType: element,
+        description: GetFieldTypeDescription(element),
+      }));
+  }, [presentFieldTypes]);
+
+  const onHelpClick = () => setIsHelpOpen((prevIsHelpOpen) => !prevIsHelpOpen);
+  const closeHelp = () => setIsHelpOpen(false);
+
+  const columnsSidebar: Array<EuiBasicTableColumn<FieldTypeTableItem>> = [
+    {
+      field: 'dataType',
+      name: 'Data type',
+      width: '110px',
+      render: (name: string) => (
+        <EuiFlexGroup alignItems="center" responsive={false} gutterSize="xs">
+          <EuiFlexItem grow={false}>
+            <FieldIcon type={name} />
+          </EuiFlexItem>
+          <EuiFlexItem>{name}</EuiFlexItem>
+        </EuiFlexGroup>
+      ),
+    },
+    {
+      field: 'description',
+      name: 'Description',
+      // eslint-disable-next-line react/no-danger
+      render: (description: string) => <div dangerouslySetInnerHTML={{ __html: description }} />,
+    },
+  ];
+
   const filterBtnAriaLabel = isPopoverOpen
     ? i18n.translate('discover.fieldChooser.toggleFieldFilterButtonHideAriaLabel', {
         defaultMessage: 'Hide field filter settings',
@@ -257,6 +311,26 @@ export function DiscoverFieldSearch({ onChange, value, types }: Props) {
     </div>
   );
 
+  const helpButton = (
+    <EuiFilterButton
+      grow={false}
+      onClick={onHelpClick}
+      data-test-subj="fieldTypesHelpButton"
+      className="dscFieldTypesHelp__button"
+      aria-label={i18n.translate('discover.fieldTypesPopover.buttonAriaLabel', {
+        defaultMessage: 'Filter type help',
+      })}
+    >
+      <EuiIcon
+        type="iInCircle"
+        color="primary"
+        title={i18n.translate('discover.fieldTypesPopover.iconTitle', {
+          defaultMessage: 'Filter type help',
+        })}
+      />
+    </EuiFilterButton>
+  );
+
   return (
     <React.Fragment>
       <EuiFlexGroup responsive={false} gutterSize={'s'}>
@@ -272,8 +346,8 @@ export function DiscoverFieldSearch({ onChange, value, types }: Props) {
         </EuiFlexItem>
       </EuiFlexGroup>
       <EuiSpacer size="xs" />
-      <EuiOutsideClickDetector onOutsideClick={() => {}} isDisabled={!isPopoverOpen}>
-        <EuiFilterGroup className="dscFieldSearch__filterWrapper">
+      <EuiFlexItem>
+        <EuiFilterGroup fullWidth>
           <EuiPopover
             id="dataPanelTypeFilter"
             panelClassName="euiFilterGroup__popoverPanel"
@@ -294,8 +368,59 @@ export function DiscoverFieldSearch({ onChange, value, types }: Props) {
             {selectionPanel}
             {footer()}
           </EuiPopover>
+          <EuiPopover
+            anchorPosition="rightUp"
+            display="block"
+            button={helpButton}
+            isOpen={isHelpOpen}
+            panelPaddingSize="none"
+            className="dscFieldTypesHelp__popover"
+            panelClassName="dscFieldTypesHelp__panel"
+            closePopover={closeHelp}
+            initialFocus="#dscFieldTypesHelpBasicTableId"
+          >
+            <EuiPopoverTitle paddingSize="s">
+              {i18n.translate('discover.fieldChooser.popoverTitle', {
+                defaultMessage: 'Field types',
+              })}
+            </EuiPopoverTitle>
+            <EuiPanel
+              className="eui-yScroll"
+              style={{ maxHeight: '50vh' }}
+              color="transparent"
+              paddingSize="s"
+            >
+              <EuiBasicTable
+                id="dscFieldTypesHelpBasicTableId"
+                tableCaption={i18n.translate('discover.fieldTypesPopover.tableTitle', {
+                  defaultMessage: 'Description of field types',
+                })}
+                items={items}
+                compressed={true}
+                rowHeader="firstName"
+                columns={columnsSidebar}
+                responsive={false}
+              />
+            </EuiPanel>
+            <EuiPanel color="transparent" paddingSize="s">
+              <EuiText color="subdued" size="xs">
+                <p>
+                  {i18n.translate('discover.fieldTypesPopover.learnMoreText', {
+                    defaultMessage: 'Learn more about',
+                  })}
+                  &nbsp;
+                  <EuiLink href={docLinks.links.discover.fieldTypeHelp}>
+                    <FormattedMessage
+                      id="discover.fieldTypesPopover.learnMoreLink"
+                      defaultMessage="field types."
+                    />
+                  </EuiLink>
+                </p>
+              </EuiText>
+            </EuiPanel>
+          </EuiPopover>
         </EuiFilterGroup>
-      </EuiOutsideClickDetector>
+      </EuiFlexItem>
     </React.Fragment>
   );
 }

src/plugins/discover/public/application/main/components/sidebar/discover_sidebar.tsx

@@ -196,16 +196,31 @@ export function DiscoverSidebarComponent({
     }
   }, [paginate, scrollContainer, unpopularFields]);
 
-  const fieldTypes = useMemo(() => {
+  const { fieldTypes, presentFieldTypes } = useMemo(() => {
     const result = ['any'];
+    const dataViewFieldTypes = new Set<string>();
     if (Array.isArray(fields)) {
       for (const field of fields) {
-        if (result.indexOf(field.type) === -1) {
-          result.push(field.type);
+        if (field.type !== '_source') {
+          // If it's a string type, we want to distinguish between keyword and text
+          // For this purpose we need the ES type
+          const type =
+            field.type === 'string' &&
+            field.esTypes &&
+            ['keyword', 'text'].includes(field.esTypes[0])
+              ? field.esTypes?.[0]
+              : field.type;
+          // _id and _index would map to string, that's why we don't add the string type here
+          if (type && type !== 'string') {
+            dataViewFieldTypes.add(type);
+          }
+          if (result.indexOf(field.type) === -1) {
+            result.push(field.type);
+          }
         }
       }
     }
-    return result;
+    return { fieldTypes: result, presentFieldTypes: Array.from(dataViewFieldTypes) };
   }, [fields]);
 
   const showFieldStats = useMemo(() => viewMode === VIEW_MODE.DOCUMENT_LEVEL, [viewMode]);
@@ -327,7 +342,7 @@ export function DiscoverSidebarComponent({
         responsive={false}
       >
         <EuiFlexItem grow={false}>
-          <EuiFlexGroup direction="row" alignItems="center" gutterSize="s">
+          <EuiFlexGroup responsive={false} direction="row" alignItems="center" gutterSize="s">
             <EuiFlexItem grow={true} className="dscSidebar__indexPatternSwitcher">
               <DiscoverIndexPattern
                 selectedIndexPattern={selectedIndexPattern}
@@ -351,6 +366,7 @@ export function DiscoverSidebarComponent({
               onChange={onChangeFieldSearch}
               value={fieldFilter.name}
               types={fieldTypes}
+              presentFieldTypes={presentFieldTypes}
             />
           </form>
         </EuiFlexItem>

src/plugins/discover/public/application/main/components/sidebar/discover_sidebar_responsive.test.tsx

@@ -51,6 +51,7 @@ const mockServices = {
       }
     },
   },
+  docLinks: { links: { discover: { fieldTypeHelp: '' } } },
 } as unknown as DiscoverServices;
 
 const mockfieldCounts: Record<string, number> = {};