AlertingNG: Refactor the query preview component (#31281)

* refactor to purecomponent

* use subscription in component

* correct onRunQueries

* move more things from render function

* fix issue with no queries

* pr feedback

* revert to FC

* redo some code layout, simplify if

* minor fixes after review

public/app/features/alerting/NextGenAlertingPage.tsx

@@ -3,8 +3,8 @@ import { hot } from 'react-hot-loader';
 import { connect, ConnectedProps } from 'react-redux';
 import { css } from 'emotion';
 import { GrafanaTheme, SelectableValue } from '@grafana/data';
+import { locationService } from '@grafana/runtime';
 import { PageToolbar, stylesFactory, ToolbarButton } from '@grafana/ui';
-
 import { config } from 'app/core/config';
 import { SplitPaneWrapper } from 'app/core/components/SplitPaneWrapper/SplitPaneWrapper';
 import { AlertingQueryEditor } from './components/AlertingQueryEditor';
@@ -97,7 +97,9 @@ class NextGenAlertingPageUnconnected extends PureComponent<Props> {
     }
   };
 
-  onDiscard = () => {};
+  onDiscard = () => {
+    locationService.replace(`${config.appSubUrl}/alerting/list`);
+  };
 
   onTest = () => {
     const { alertDefinition, evaluateAlertDefinition, evaluateNotSavedAlertDefinition } = this.props;
@@ -125,12 +127,12 @@ class NextGenAlertingPageUnconnected extends PureComponent<Props> {
   render() {
     const {
       alertDefinition,
-      getInstances,
       uiState,
       updateAlertDefinitionUiState,
-      queryRunner,
       getQueryOptions,
+      getInstances,
       onRunQueries,
+      queryRunner,
     } = this.props;
 
     const styles = getStyles(config.theme);
@@ -146,10 +148,10 @@ class NextGenAlertingPageUnconnected extends PureComponent<Props> {
             leftPaneComponents={[
               <AlertingQueryPreview
                 key="queryPreview"
-                queryRunner={queryRunner!} // if the queryRunner is undefined here somethings very wrong so it's ok to throw an unhandled error
-                getInstances={getInstances}
-                queries={queryOptions.queries}
                 onTest={this.onTest}
+                queries={queryOptions.queries}
+                getInstances={getInstances}
+                queryRunner={queryRunner!}
                 onRunQueries={onRunQueries}
               />,
               <AlertingQueryEditor key="queryEditor" />,

public/app/features/alerting/components/AlertingQueryPreview.tsx

@@ -3,10 +3,12 @@ import { useObservable } from 'react-use';
 import { css } from 'emotion';
 import AutoSizer from 'react-virtualized-auto-sizer';
 import { DataFrame, DataQuery, GrafanaTheme, PanelData } from '@grafana/data';
-import { Button, Icon, Tab, TabContent, TabsBar, useStyles } from '@grafana/ui';
-import { PanelQueryRunner } from '../../query/state/PanelQueryRunner';
+import { config } from '@grafana/runtime';
+import { Icon, Tab, TabContent, TabsBar } from '@grafana/ui';
 import { PreviewQueryTab } from './PreviewQueryTab';
 import { PreviewInstancesTab } from './PreviewInstancesTab';
+import { EmptyState } from './EmptyState';
+import { PanelQueryRunner } from '../../query/state/PanelQueryRunner';
 
 enum Tabs {
   Query = 'query',
@@ -26,10 +28,9 @@ interface Props {
   onRunQueries: () => void;
 }
 
-export const AlertingQueryPreview: FC<Props> = ({ getInstances, onRunQueries, onTest, queryRunner, queries }) => {
+export const AlertingQueryPreview: FC<Props> = ({ getInstances, onRunQueries, onTest, queries, queryRunner }) => {
   const [activeTab, setActiveTab] = useState<string>(Tabs.Query);
-  const styles = useStyles(getStyles);
-
+  const styles = getStyles(config.theme);
   const observable = useMemo(() => queryRunner.getData({ withFieldConfig: true, withTransforms: true }), []);
   const data = useObservable<PanelData>(observable);
   const instances = getInstances();
@@ -49,59 +50,66 @@ export const AlertingQueryPreview: FC<Props> = ({ getInstances, onRunQueries, on
         })}
       </TabsBar>
       <TabContent className={styles.tabContent}>
-        {data && data.state === 'Error' ? (
-          <div className={styles.noQueries}>
-            <h4 className={styles.noQueriesHeader}>There was an error :(</h4>
-            <div>{data.error?.data?.error}</div>
-          </div>
-        ) : queries && queries.length > 0 ? (
-          <AutoSizer style={{ width: '100%', height: '100%' }}>
-            {({ width, height }) => {
-              switch (activeTab) {
-                case Tabs.Instances:
-                  return (
-                    <PreviewInstancesTab
-                      isTested={instances.length > 0}
-                      instances={instances}
-                      styles={styles}
-                      width={width}
-                      height={height}
-                      onTest={onTest}
-                    />
-                  );
-
-                case Tabs.Query:
-                default:
-                  if (data) {
-                    return <PreviewQueryTab data={data} width={width} height={height} />;
-                  }
-                  return (
-                    <div className={styles.noQueries}>
-                      <h4 className={styles.noQueriesHeader}>Run queries to view data.</h4>
-                      <Button onClick={onRunQueries}>Run queries</Button>
-                    </div>
-                  );
-              }
-            }}
-          </AutoSizer>
-        ) : (
-          <div className={styles.noQueries}>
-            <h4 className={styles.noQueriesHeader}>No queries added.</h4>
-            <div>Start adding queries to this alert and a visualisation for your queries will appear here.</div>
-            <div>
-              Learn more about how to create alert definitions <Icon name="external-link-alt" />
-            </div>
-          </div>
-        )}
+        {data &&
+          (data.state === 'Error' ? (
+            <EmptyState title="There was an error :(">
+              <div>{data.error?.data?.error}</div>
+            </EmptyState>
+          ) : (
+            <QueriesAndInstances
+              instances={instances}
+              onTest={onTest}
+              data={data}
+              activeTab={activeTab}
+              onRunQueries={onRunQueries}
+              queries={queries}
+            />
+          ))}
       </TabContent>
     </div>
   );
 };
 
+interface PreviewProps {
+  queries: DataQuery[];
+  instances: DataFrame[];
+  onTest: () => void;
+  data: PanelData;
+  activeTab: string;
+  onRunQueries: () => void;
+}
+
+const QueriesAndInstances: FC<PreviewProps> = ({ queries, instances, onTest, data, activeTab, onRunQueries }) => {
+  if (queries.length === 0) {
+    return (
+      <EmptyState title="No queries added.">
+        <div>Start adding queries to this alert and a visualisation for your queries will appear here.</div>
+        <div>
+          Learn more about how to create alert definitions <Icon name="external-link-alt" />
+        </div>
+      </EmptyState>
+    );
+  }
+
+  return (
+    <AutoSizer style={{ width: '100%', height: '100%' }}>
+      {({ width, height }) => {
+        switch (activeTab) {
+          case Tabs.Instances:
+            return <PreviewInstancesTab instances={instances} width={width} height={height} onTest={onTest} />;
+
+          case Tabs.Query:
+          default:
+            return <PreviewQueryTab data={data} width={width} height={height} onRunQueries={onRunQueries} />;
+        }
+      }}
+    </AutoSizer>
+  );
+};
+
 const getStyles = (theme: GrafanaTheme) => {
   return {
     wrapper: css`
-      label: alertDefinitionPreviewTabs;
       display: flex;
       flex-direction: column;
       width: 100%;
@@ -112,19 +120,5 @@ const getStyles = (theme: GrafanaTheme) => {
       background: ${theme.colors.panelBg};
       height: 100%;
     `,
-    noQueries: css`
-      color: ${theme.colors.textSemiWeak};
-      display: flex;
-      flex-direction: column;
-      justify-content: center;
-      align-items: center;
-      height: 100%;
-      width: 100%;
-    `,
-    noQueriesHeader: css`
-      color: ${theme.colors.textSemiWeak};
-    `,
   };
 };
-
-export type PreviewStyles = ReturnType<typeof getStyles>;

public/app/features/alerting/components/EmptyState.tsx

@@ -0,0 +1,37 @@
+import React, { FC, ReactNode } from 'react';
+import { css } from 'emotion';
+import { useStyles } from '@grafana/ui';
+import { GrafanaTheme } from '@grafana/data';
+
+interface Props {
+  title: string;
+  children: ReactNode | ReactNode[];
+}
+
+export const EmptyState: FC<Props> = ({ children, title }) => {
+  const styles = useStyles(getStyles);
+
+  return (
+    <div className={styles.emptyState}>
+      <h4 className={styles.emptyStateHeader}>{title}</h4>
+      {children}
+    </div>
+  );
+};
+
+const getStyles = (theme: GrafanaTheme) => {
+  return {
+    emptyState: css`
+      color: ${theme.colors.textSemiWeak};
+      display: flex;
+      flex-direction: column;
+      justify-content: center;
+      align-items: center;
+      height: 100%;
+      width: 100%;
+    `,
+    emptyStateHeader: css`
+      color: ${theme.colors.textSemiWeak};
+    `,
+  };
+};

public/app/features/alerting/components/PreviewInstancesTab.tsx

@@ -1,25 +1,22 @@
 import React, { FC } from 'react';
 import { DataFrame } from '@grafana/data';
 import { Button, Table } from '@grafana/ui';
-import { PreviewStyles } from './AlertingQueryPreview';
+import { EmptyState } from './EmptyState';
 
 interface Props {
   instances: DataFrame[];
-  isTested: boolean;
-  styles: PreviewStyles;
   width: number;
   height: number;
   onTest: () => void;
 }
 
-export const PreviewInstancesTab: FC<Props> = ({ instances, isTested, onTest, height, styles, width }) => {
-  if (!isTested) {
+export const PreviewInstancesTab: FC<Props> = ({ instances, onTest, height, width }) => {
+  if (!instances.length) {
     return (
-      <div className={styles.noQueries}>
-        <h4 className={styles.noQueriesHeader}>You haven’t tested your alert yet.</h4>
+      <EmptyState title="You haven’t tested your alert yet.">
         <div>In order to see your instances, you need to test your alert first.</div>
         <Button onClick={onTest}>Test alert now</Button>
-      </div>
+      </EmptyState>
     );
   }
   return <Table data={instances[0]} height={height} width={width} />;

public/app/features/alerting/components/PreviewQueryTab.tsx

@@ -1,15 +1,17 @@
 import React, { FC, useMemo, useState } from 'react';
-import { getFrameDisplayName, GrafanaTheme, PanelData, SelectableValue, toDataFrame } from '@grafana/data';
-import { Select, stylesFactory, Table, useTheme } from '@grafana/ui';
 import { css } from 'emotion';
+import { getFrameDisplayName, GrafanaTheme, PanelData, SelectableValue } from '@grafana/data';
+import { Button, Select, stylesFactory, Table, useTheme } from '@grafana/ui';
+import { EmptyState } from './EmptyState';
 
 interface Props {
-  data?: PanelData;
+  data: PanelData;
   width: number;
   height: number;
+  onRunQueries: () => void;
 }
 
-export const PreviewQueryTab: FC<Props> = ({ data, height, width }) => {
+export const PreviewQueryTab: FC<Props> = ({ data, height, onRunQueries, width }) => {
   const [currentSeries, setSeries] = useState<number>(0);
   const theme = useTheme();
   const styles = getStyles(theme, height);
@@ -24,8 +26,16 @@ export const PreviewQueryTab: FC<Props> = ({ data, height, width }) => {
   // Select padding
   const padding = 16;
 
-  if (!data?.series?.length) {
-    return <Table data={toDataFrame([])} height={height} width={width} />;
+  if (!data) {
+    return (
+      <EmptyState title="Run queries to view data.">
+        <Button onClick={onRunQueries}>Run queries</Button>
+      </EmptyState>
+    );
+  }
+
+  if (!data.series) {
+    return null;
   }
 
   if (data.series.length > 1) {
@@ -48,12 +58,14 @@ export const PreviewQueryTab: FC<Props> = ({ data, height, width }) => {
       </div>
     );
   }
+
   return <Table data={data.series[0]} height={height} width={width} />;
 };
 
 const getStyles = stylesFactory((theme: GrafanaTheme, height: number) => {
   return {
     wrapper: css`
+      label: preview-wrapper;
       height: ${height}px;
     `,
     selectWrapper: css`