UI: Segment fixes (#20947)

* Add support for primitive values/onchange

* Fix segment clickaway bug

* Fix onchange

* Use primitive in cloudwatch

* Add placeholder

* Use placeholder in cloudwatch editor

* Fix lint error

* Fix lodash import

* Use new component story format

* Add support for autofocus

* Use selectable value for onchange event

* Fix lint error

packages/grafana-ui/src/components/Segment/Segment.story.tsx

@@ -1,12 +1,6 @@
-import React from 'react';
-import { storiesOf } from '@storybook/react';
+import React, { useState } from 'react';
 import { action } from '@storybook/addon-actions';
-
-import { SelectableValue } from '@grafana/data';
 import { Segment } from './';
-import { UseState } from '../../utils/storybook/UseState';
-
-const SegmentStories = storiesOf('UI/Segment/SegmentSync', module);
 
 const AddButton = (
   <a className="gf-form-label query-part">
@@ -15,131 +9,125 @@ const AddButton = (
 );
 
 const toOption = (value: any) => ({ label: value, value: value });
-
-SegmentStories.add('Array Options', () => {
-  const options = ['Option1', 'Option2', 'OptionWithLooongLabel', 'Option4'].map(toOption);
-  options[0].label = 'Option1 Label';
-  return (
-    <UseState initialState={options[0] as SelectableValue}>
-      {(value, updateValue) => (
-        <>
-          <div className="gf-form-inline">
-            <div className="gf-form">
-              <span className="gf-form-label width-8 query-keyword">Segment Name</span>
-            </div>
-            <Segment
-              value={value}
-              options={options}
-              onChange={item => {
-                updateValue(item);
-                action('Segment value changed')(item.value);
-              }}
-            />
-            <Segment
-              Component={AddButton}
-              onChange={(value: SelectableValue<string>) => action('New value added')(value)}
-              options={options}
-            />
-          </div>
-        </>
-      )}
-    </UseState>
-  );
-});
-
+const options = ['Option1', 'Option2', 'OptionWithLooongLabel', 'Option4'].map(toOption);
 const groupedOptions = [
   { label: 'Names', options: ['Jane', 'Tom', 'Lisa'].map(toOption) },
   { label: 'Prime', options: [2, 3, 5, 7, 11, 13].map(toOption) },
 ];
 
-SegmentStories.add('Grouped Array Options', () => {
+const SegmentFrame = ({ options, children }: any) => (
+  <>
+    <div className="gf-form-inline">
+      <div className="gf-form">
+        <span className="gf-form-label width-8 query-keyword">Segment Name</span>
+      </div>
+      {children}
+      <Segment Component={AddButton} onChange={({ value }) => action('New value added')(value)} options={options} />
+    </div>
+  </>
+);
+
+export const ArrayOptions = () => {
+  const [value, setValue] = useState<any>(options[0]);
+  return (
+    <SegmentFrame options={options}>
+      <Segment
+        value={value}
+        options={options}
+        onChange={item => {
+          setValue(item);
+          action('Segment value changed')(item.value);
+        }}
+      />
+    </SegmentFrame>
+  );
+};
+
+export default {
+  title: 'UI/Segment/SegmentSync',
+  component: ArrayOptions,
+};
+
+export const ArrayOptionsWithPrimitiveValue = () => {
+  const [value, setValue] = useState('Option1');
+  return (
+    <SegmentFrame options={options}>
+      <Segment
+        value={value}
+        options={options}
+        onChange={({ value }) => {
+          setValue(value);
+          action('Segment value changed')(value);
+        }}
+      />
+    </SegmentFrame>
+  );
+};
+
+export const ArrayOptionsWithPlaceholder = () => {
+  const [value, setValue] = useState<any>(undefined);
+  return (
+    <SegmentFrame options={options}>
+      <Segment
+        value={value}
+        options={options}
+        placeholder="Enter a value"
+        onChange={item => {
+          setValue(item);
+          action('Segment value changed')(item.value);
+        }}
+      />
+    </SegmentFrame>
+  );
+};
+
+export const GroupedArrayOptions = () => {
+  const [value, setValue] = useState<any>(groupedOptions[0].options[0]);
   return (
-    <UseState initialState={groupedOptions[0].options[0] as SelectableValue}>
-      {(value, updateValue) => (
-        <>
-          <div className="gf-form-inline">
-            <div className="gf-form">
-              <span className="gf-form-label width-8 query-keyword">Segment Name</span>
-            </div>
-            <Segment
-              value={value}
-              options={groupedOptions}
-              onChange={item => {
-                updateValue(item);
-                action('Segment value changed')(item.value);
-              }}
-            />
-            <Segment
-              Component={AddButton}
-              onChange={value => action('New value added')(value)}
-              options={groupedOptions}
-            />
-          </div>
-        </>
-      )}
-    </UseState>
+    <SegmentFrame options={options}>
+      <Segment
+        value={value}
+        options={groupedOptions}
+        onChange={item => {
+          setValue(item);
+          action('Segment value changed')(item.value);
+        }}
+      />
+    </SegmentFrame>
   );
-});
+};
 
-SegmentStories.add('With custom options allowed', () => {
-  const options = ['Option1', 'Option2', 'OptionWithLooongLabel', 'Option4'].map(toOption);
+export const CustomOptionsAllowed = () => {
+  const [value, setValue] = useState(options[0]);
   return (
-    <UseState initialState={options[0] as SelectableValue}>
-      {(value, updateValue) => (
-        <>
-          <div className="gf-form-inline">
-            <div className="gf-form">
-              <span className="gf-form-label width-8 query-keyword">Segment Name</span>
-            </div>
-            <Segment
-              allowCustomValue
-              value={value}
-              options={options}
-              onChange={item => {
-                updateValue(item);
-                action('Segment value changed')(item.value);
-              }}
-            />
-            <Segment
-              allowCustomValue
-              Component={AddButton}
-              onChange={(value: SelectableValue<string>) => action('New value added')(value)}
-              options={options}
-            />
-          </div>
-        </>
-      )}
-    </UseState>
+    <SegmentFrame options={options}>
+      <Segment
+        allowCustomValue
+        value={value}
+        options={options}
+        onChange={({ value }) => {
+          setValue(value);
+          action('Segment value changed')(value);
+        }}
+      />
+    </SegmentFrame>
   );
-});
+};
 
-const CustomLabelComponent = ({ value: { value } }: any) => <div className="gf-form-label">custom({value})</div>;
+const CustomLabelComponent = ({ value }: any) => <div className="gf-form-label">custom({value})</div>;
 
-SegmentStories.add('Custom Label Field', () => {
+export const CustomLabelField = () => {
+  const [value, setValue] = useState<any>(groupedOptions[0].options[0].value);
   return (
-    <UseState initialState={groupedOptions[0].options[0] as SelectableValue}>
-      {(value, setValue) => (
-        <>
-          <div className="gf-form-inline">
-            <div className="gf-form">
-              <span className="gf-form-label width-8 query-keyword">Segment Name</span>
-            </div>
-            <Segment
-              Component={<CustomLabelComponent value={value} />}
-              options={groupedOptions}
-              onChange={item => {
-                setValue(item);
-                action('Segment value changed')(item.value);
-              }}
-            />
-            <Segment
-              Component={AddButton}
-              onChange={value => action('New value added')(value)}
-              options={groupedOptions}
-            />
-          </div>
-        </>
-      )}
-    </UseState>
+    <SegmentFrame options={options}>
+      <Segment
+        Component={<CustomLabelComponent value={value} />}
+        options={groupedOptions}
+        onChange={({ value }) => {
+          setValue(value);
+          action('Segment value changed')(value);
+        }}
+      />
+    </SegmentFrame>
   );
-});
+};

packages/grafana-ui/src/components/Segment/Segment.tsx

@@ -1,10 +1,11 @@
 import React from 'react';
 import { cx } from 'emotion';
+import _ from 'lodash';
 import { SelectableValue } from '@grafana/data';
 import { SegmentSelect, useExpandableLabel, SegmentProps } from './';
 
 export interface SegmentSyncProps<T> extends SegmentProps<T> {
-  value?: SelectableValue<T>;
+  value?: T | SelectableValue<T>;
   onChange: (item: SelectableValue<T>) => void;
   options: Array<SelectableValue<T>>;
 }
@@ -16,20 +17,28 @@ export function Segment<T>({
   Component,
   className,
   allowCustomValue,
+  placeholder,
 }: React.PropsWithChildren<SegmentSyncProps<T>>) {
   const [Label, width, expanded, setExpanded] = useExpandableLabel(false);
 
   if (!expanded) {
+    const label = _.isObject(value) ? value.label : value;
     return (
       <Label
-        Component={Component || <a className={cx('gf-form-label', 'query-part', className)}>{value && value.label}</a>}
+        Component={
+          Component || (
+            <a className={cx('gf-form-label', 'query-part', !value && placeholder && 'query-placeholder', className)}>
+              {label || placeholder}
+            </a>
+          )
+        }
       />
     );
   }
 
   return (
     <SegmentSelect
-      value={value}
+      value={value && !_.isObject(value) ? { value } : value}
       options={options}
       width={width}
       onClickOutside={() => setExpanded(false)}

packages/grafana-ui/src/components/Segment/SegmentAsync.story.tsx

@@ -1,10 +1,7 @@
-import React from 'react';
-import { storiesOf } from '@storybook/react';
+import React, { useState } from 'react';
 import { action } from '@storybook/addon-actions';
 import { SelectableValue } from '@grafana/data';
-const SegmentStories = storiesOf('UI/Segment/SegmentAsync', module);
 import { SegmentAsync } from './';
-import { UseState } from '../../utils/storybook/UseState';
 
 const AddButton = (
   <a className="gf-form-label query-part">
@@ -13,132 +10,116 @@ const AddButton = (
 );
 
 const toOption = (value: any) => ({ label: value, value: value });
+const options = ['Option1', 'Option2', 'OptionWithLooongLabel', 'Option4'].map(toOption);
 
 const loadOptions = (options: any): Promise<Array<SelectableValue<string>>> =>
   new Promise(res => setTimeout(() => res(options), 2000));
 
-SegmentStories.add('Array Options', () => {
-  const options = ['Option1', 'Option2', 'OptionWithLooongLabel', 'Option4'].map(toOption);
+const SegmentFrame = ({ loadOptions, children }: any) => (
+  <>
+    <div className="gf-form-inline">
+      <div className="gf-form">
+        <span className="gf-form-label width-8 query-keyword">Segment Name</span>
+      </div>
+      {children}
+      <SegmentAsync
+        Component={AddButton}
+        onChange={value => action('New value added')(value)}
+        loadOptions={() => loadOptions(options)}
+      />
+    </div>
+  </>
+);
+
+export const ArrayOptions = () => {
+  const [value, setValue] = useState<any>(options[0]);
   return (
-    <UseState initialState={options[0] as SelectableValue}>
-      {(value, updateValue) => (
-        <>
-          <div className="gf-form-inline">
-            <div className="gf-form">
-              <span className="gf-form-label width-8 query-keyword">Segment Name</span>
-            </div>
-            <SegmentAsync
-              value={value}
-              loadOptions={() => loadOptions(options)}
-              onChange={item => {
-                updateValue(item);
-                action('Segment value changed')(item.value);
-              }}
-            />
-            <SegmentAsync
-              Component={AddButton}
-              onChange={value => action('New value added')(value)}
-              loadOptions={() => loadOptions(options)}
-            />
-          </div>
-        </>
-      )}
-    </UseState>
+    <SegmentFrame loadOptions={() => loadOptions(options)}>
+      <SegmentAsync
+        value={value}
+        loadOptions={() => loadOptions(options)}
+        onChange={item => {
+          setValue(item);
+          action('Segment value changed')(item.value);
+        }}
+      />
+    </SegmentFrame>
   );
-});
+};
 
-const groupedOptions = [
+export default {
+  title: 'UI/Segment/SegmentAsync',
+  component: ArrayOptions,
+};
+
+export const ArrayOptionsWithPrimitiveValue = () => {
+  const [value, setValue] = useState(options[0].value);
+  return (
+    <SegmentFrame loadOptions={() => loadOptions(options)}>
+      <SegmentAsync
+        value={value}
+        loadOptions={() => loadOptions(options)}
+        onChange={({ value }) => {
+          setValue(value);
+          action('Segment value changed')(value);
+        }}
+      />
+    </SegmentFrame>
+  );
+};
+
+const groupedOptions: any = [
   { label: 'Names', options: ['Jane', 'Tom', 'Lisa'].map(toOption) },
   { label: 'Prime', options: [2, 3, 5, 7, 11, 13].map(toOption) },
 ];
 
-SegmentStories.add('Grouped Array Options', () => {
+export const GroupedArrayOptions = () => {
+  const [value, setValue] = useState(groupedOptions[0].options[0]);
   return (
-    <UseState initialState={groupedOptions[0].options[0] as SelectableValue}>
-      {(value, updateValue) => (
-        <>
-          <div className="gf-form-inline">
-            <div className="gf-form">
-              <span className="gf-form-label width-8 query-keyword">Segment Name</span>
-            </div>
-            <SegmentAsync
-              value={value}
-              loadOptions={() => loadOptions(groupedOptions)}
-              onChange={item => {
-                updateValue(item);
-                action('Segment value changed')(item.value);
-              }}
-            />
-            <SegmentAsync
-              Component={AddButton}
-              onChange={value => action('New value added')(value)}
-              loadOptions={() => loadOptions(groupedOptions)}
-            />
-          </div>
-        </>
-      )}
-    </UseState>
+    <SegmentFrame loadOptions={() => loadOptions(groupedOptions)}>
+      <SegmentAsync
+        value={value}
+        loadOptions={() => loadOptions(groupedOptions)}
+        onChange={item => {
+          setValue(item);
+          action('Segment value changed')(item.value);
+        }}
+      />
+    </SegmentFrame>
   );
-});
+};
 
-SegmentStories.add('With custom options allowed', () => {
-  const options = ['Option1', 'Option2', 'OptionWithLooongLabel', 'Option4'].map(toOption);
+export const CustomOptionsAllowed = () => {
+  const [value, setValue] = useState(groupedOptions[0].options[0]);
   return (
-    <UseState initialState={options[0] as SelectableValue}>
-      {(value, updateValue) => (
-        <>
-          <div className="gf-form-inline">
-            <div className="gf-form">
-              <span className="gf-form-label width-8 query-keyword">Segment Name</span>
-            </div>
-            <SegmentAsync
-              allowCustomValue
-              value={value}
-              loadOptions={() => loadOptions(options)}
-              onChange={item => {
-                updateValue(item);
-                action('Segment value changed')(item.value);
-              }}
-            />
-            <SegmentAsync
-              allowCustomValue
-              Component={AddButton}
-              onChange={value => action('New value added')(value)}
-              loadOptions={() => loadOptions(options)}
-            />
-          </div>
-        </>
-      )}
-    </UseState>
+    <SegmentFrame loadOptions={() => loadOptions(groupedOptions)}>
+      <SegmentAsync
+        allowCustomValue
+        value={value}
+        loadOptions={() => loadOptions(options)}
+        onChange={item => {
+          setValue(item);
+          action('Segment value changed')(item.value);
+        }}
+      />
+    </SegmentFrame>
   );
-});
+};
+
+const CustomLabelComponent = ({ value }: any) => <div className="gf-form-label">custom({value})</div>;
 
-const CustomLabelComponent = ({ value: { value } }: any) => <div className="gf-form-label">custom({value})</div>;
-SegmentStories.add('Custom Label Field', () => {
+export const CustomLabel = () => {
+  const [value, setValue] = useState(groupedOptions[0].options[0].value);
   return (
-    <UseState initialState={groupedOptions[0].options[0] as SelectableValue}>
-      {(value, updateValue) => (
-        <>
-          <div className="gf-form-inline">
-            <div className="gf-form">
-              <span className="gf-form-label width-8 query-keyword">Segment Name</span>
-            </div>
-            <SegmentAsync
-              Component={<CustomLabelComponent value={value} />}
-              loadOptions={() => loadOptions(groupedOptions)}
-              onChange={item => {
-                updateValue(item);
-                action('Segment value changed')(item.value);
-              }}
-            />
-            <SegmentAsync
-              Component={AddButton}
-              onChange={value => action('New value added')(value)}
-              loadOptions={() => loadOptions(groupedOptions)}
-            />
-          </div>
-        </>
-      )}
-    </UseState>
+    <SegmentFrame loadOptions={() => loadOptions(groupedOptions)}>
+      <SegmentAsync
+        Component={<CustomLabelComponent value={value} />}
+        loadOptions={() => loadOptions(groupedOptions)}
+        onChange={({ value }) => {
+          setValue(value);
+          action('Segment value changed')(value);
+        }}
+      />
+    </SegmentFrame>
   );
-});
+};

packages/grafana-ui/src/components/Segment/SegmentAsync.tsx

@@ -1,11 +1,12 @@
 import React, { useState } from 'react';
 import { cx } from 'emotion';
+import _ from 'lodash';
 import { SegmentSelect } from './SegmentSelect';
 import { SelectableValue } from '@grafana/data';
 import { useExpandableLabel, SegmentProps } from '.';
 
 export interface SegmentAsyncProps<T> extends SegmentProps<T> {
-  value?: SelectableValue<T>;
+  value?: T | SelectableValue<T>;
   loadOptions: (query?: string) => Promise<Array<SelectableValue<T>>>;
   onChange: (item: SelectableValue<T>) => void;
 }
@@ -17,12 +18,14 @@ export function SegmentAsync<T>({
   Component,
   className,
   allowCustomValue,
+  placeholder,
 }: React.PropsWithChildren<SegmentAsyncProps<T>>) {
   const [selectPlaceholder, setSelectPlaceholder] = useState<string>('');
   const [loadedOptions, setLoadedOptions] = useState<Array<SelectableValue<T>>>([]);
   const [Label, width, expanded, setExpanded] = useExpandableLabel(false);
 
   if (!expanded) {
+    const label = _.isObject(value) ? value.label : value;
     return (
       <Label
         onClick={async () => {
@@ -31,14 +34,20 @@ export function SegmentAsync<T>({
           setLoadedOptions(opts);
           setSelectPlaceholder(opts.length ? '' : 'No options found');
         }}
-        Component={Component || <a className={cx('gf-form-label', 'query-part', className)}>{value && value.label}</a>}
+        Component={
+          Component || (
+            <a className={cx('gf-form-label', 'query-part', !value && placeholder && 'query-placeholder', className)}>
+              {label || placeholder}
+            </a>
+          )
+        }
       />
     );
   }
 
   return (
     <SegmentSelect
-      value={value}
+      value={value && !_.isObject(value) ? { value } : value}
       options={loadedOptions}
       width={width}
       noOptionsMessage={selectPlaceholder}

packages/grafana-ui/src/components/Segment/SegmentInput.story.tsx

@@ -1,29 +1,84 @@
-import React from 'react';
-import { storiesOf } from '@storybook/react';
+import React, { useState } from 'react';
 import { action } from '@storybook/addon-actions';
-const SegmentStories = storiesOf('UI/Segment/SegmentInput', module);
 import { SegmentInput } from '.';
-import { UseState } from '../../utils/storybook/UseState';
 
-SegmentStories.add('Segment Input', () => {
+const SegmentFrame = ({ children }: any) => (
+  <>
+    <div className="gf-form-inline">
+      <div className="gf-form">
+        <span className="gf-form-label width-8 query-keyword">Segment Name</span>
+      </div>
+      {children}
+    </div>
+  </>
+);
+
+export const BasicInput = () => {
+  const [value, setValue] = useState('some text');
+  return (
+    <SegmentFrame>
+      <SegmentInput
+        value={value}
+        onChange={text => {
+          setValue(text as string);
+          action('Segment value changed')(text);
+        }}
+      />
+    </SegmentFrame>
+  );
+};
+
+export default {
+  title: 'UI/Segment/SegmentInput',
+  component: BasicInput,
+};
+
+export const BasicInputWithPlaceholder = () => {
+  const [value, setValue] = useState('');
+  return (
+    <SegmentFrame>
+      <SegmentInput
+        placeholder="add text"
+        value={value}
+        onChange={text => {
+          setValue(text as string);
+          action('Segment value changed')(text);
+        }}
+      />
+    </SegmentFrame>
+  );
+};
+
+const InputComponent = ({ initialValue }: any) => {
+  const [value, setValue] = useState(initialValue);
+  return (
+    <SegmentInput
+      placeholder="add text"
+      autofocus
+      value={value}
+      onChange={text => {
+        setValue(text as string);
+        action('Segment value changed')(text);
+      }}
+    />
+  );
+};
+
+export const InputWithAutoFocus = () => {
+  const [inputComponents, setInputComponents] = useState<any>([]);
   return (
-    <UseState initialState={'some text'}>
-      {(value, updateValue) => (
-        <>
-          <div className="gf-form-inline">
-            <div className="gf-form">
-              <span className="gf-form-label width-8 query-keyword">Segment Name</span>
-            </div>
-            <SegmentInput
-              value={value}
-              onChange={text => {
-                updateValue(text as string);
-                action('Segment value changed')(text);
-              }}
-            />
-          </div>
-        </>
-      )}
-    </UseState>
+    <SegmentFrame>
+      {inputComponents.map((InputComponent: any) => (
+        <InputComponent intitialValue="test"></InputComponent>
+      ))}
+      <a
+        className="gf-form-label query-part"
+        onClick={() => {
+          setInputComponents([...inputComponents, InputComponent]);
+        }}
+      >
+        <i className="fa fa-plus" />
+      </a>
+    </SegmentFrame>
   );
-});
+};

packages/grafana-ui/src/components/Segment/SegmentInput.tsx

@@ -7,6 +7,7 @@ import { useExpandableLabel, SegmentProps } from '.';
 export interface SegmentInputProps<T> extends SegmentProps<T> {
   value: string | number;
   onChange: (text: string | number) => void;
+  autofocus?: boolean;
 }
 
 const FONT_SIZE = 14;
@@ -16,16 +17,30 @@ export function SegmentInput<T>({
   onChange,
   Component,
   className,
+  placeholder,
+  autofocus = false,
 }: React.PropsWithChildren<SegmentInputProps<T>>) {
-  const ref = useRef(null);
+  const ref = useRef<HTMLInputElement>(null);
   const [value, setValue] = useState<number | string>(initialValue);
-  const [inputWidth, setInputWidth] = useState<number>(measureText(initialValue.toString(), FONT_SIZE).width);
-  const [Label, , expanded, setExpanded] = useExpandableLabel(false);
-  useClickAway(ref, () => setExpanded(false));
+  const [inputWidth, setInputWidth] = useState<number>(measureText((initialValue || '').toString(), FONT_SIZE).width);
+  const [Label, , expanded, setExpanded] = useExpandableLabel(autofocus);
+
+  useClickAway(ref, () => {
+    setExpanded(false);
+    onChange(value);
+  });
 
   if (!expanded) {
     return (
-      <Label Component={Component || <a className={cx('gf-form-label', 'query-part', className)}>{initialValue}</a>} />
+      <Label
+        Component={
+          Component || (
+            <a className={cx('gf-form-label', 'query-part', !value && placeholder && 'query-placeholder', className)}>
+              {initialValue || placeholder}
+            </a>
+          )
+        }
+      />
     );
   }
 

packages/grafana-ui/src/components/Segment/types.ts

@@ -4,4 +4,5 @@ export interface SegmentProps<T> {
   Component?: ReactElement;
   className?: string;
   allowCustomValue?: boolean;
+  placeholder?: string;
 }

public/app/plugins/datasource/cloudwatch/components/Dimensions.tsx

@@ -34,15 +34,13 @@ export const Dimensions: FunctionComponent<Props> = ({ dimensions, loadValues, l
     return options.filter(({ value }) => !Object.keys(data).includes(value));
   };
 
-  const toOption = (value: any) => ({ label: value, value });
-
   return (
     <>
       {Object.entries(data).map(([key, value], index) => (
         <Fragment key={index}>
           <SegmentAsync
             allowCustomValue
-            value={toOption(key)}
+            value={key}
             loadOptions={() => loadKeys().then(keys => [removeOption, ...excludeUsedKeys(keys)])}
             onChange={({ value: newKey }) => {
               const { [key]: value, ...newDimensions } = data;
@@ -56,7 +54,8 @@ export const Dimensions: FunctionComponent<Props> = ({ dimensions, loadValues, l
           <label className="gf-form-label query-segment-operator">=</label>
           <SegmentAsync
             allowCustomValue
-            value={toOption(value || 'select dimension value')}
+            value={value}
+            placeholder="select dimension value"
             loadOptions={() => loadValues(key)}
             onChange={({ value: newValue }) => setData({ ...data, [key]: newValue })}
           />

public/app/plugins/datasource/cloudwatch/components/QueryEditor.tsx

@@ -112,7 +112,8 @@ export class QueryEditor extends PureComponent<Props, State> {
       <>
         <QueryInlineField label="Region">
           <Segment
-            value={this.toOption(query.region || 'Select region')}
+            value={query.region}
+            placeholder="Select region"
             options={regions}
             allowCustomValue
             onChange={({ value: region }) => this.onChange({ ...query, region })}
@@ -123,7 +124,8 @@ export class QueryEditor extends PureComponent<Props, State> {
           <>
             <QueryInlineField label="Namespace">
               <Segment
-                value={this.toOption(query.namespace || 'Select namespace')}
+                value={query.namespace}
+                placeholder="Select namespace"
                 allowCustomValue
                 options={namespaces}
                 onChange={({ value: namespace }) => this.onChange({ ...query, namespace })}
@@ -132,7 +134,8 @@ export class QueryEditor extends PureComponent<Props, State> {
 
             <QueryInlineField label="Metric Name">
               <SegmentAsync
-                value={this.toOption(query.metricName || 'Select metric name')}
+                value={query.metricName}
+                placeholder="Select metric name"
                 allowCustomValue
                 loadOptions={this.loadMetricNames}
                 onChange={({ value: metricName }) => this.onChange({ ...query, metricName })}

public/app/plugins/datasource/cloudwatch/components/Stats.tsx

@@ -12,7 +12,6 @@ export interface Props {
 
 const removeText = '-- remove stat --';
 const removeOption: SelectableValue<string> = { label: removeText, value: removeText };
-const toOption = (value: any) => ({ label: value, value });
 
 export const Stats: FunctionComponent<Props> = ({ stats, values, onChange, variableOptionGroup }) => (
   <>
@@ -21,7 +20,7 @@ export const Stats: FunctionComponent<Props> = ({ stats, values, onChange, varia
         <Segment
           allowCustomValue
           key={value + index}
-          value={toOption(value)}
+          value={value}
           options={[removeOption, ...stats, variableOptionGroup]}
           onChange={({ value }) =>
             onChange(

public/sass/components/_query_editor.scss

@@ -7,6 +7,10 @@
   color: $orange;
 }
 
+.query-placeholder {
+  color: $gray-2;
+}
+
 .query-editor-rows {
   margin: 20px 0;
 }