Preserve template variable name when editing type

ui/src/tempVars/components/TemplateVariableEditor.tsx

@@ -182,10 +182,10 @@ class TemplateVariableEditor extends PureComponent<Props, State> {
 
   private handleChooseType = ({type}) => {
     const {
-      nextTemplate: {id},
+      nextTemplate: {id, tempVar},
     } = this.state
 
-    const nextNextTemplate = {...DEFAULT_TEMPLATES[type](), id}
+    const nextNextTemplate = {...DEFAULT_TEMPLATES[type](), id, tempVar}
 
     this.setState({nextTemplate: nextNextTemplate})
   }
@@ -204,7 +204,12 @@ class TemplateVariableEditor extends PureComponent<Props, State> {
 
   private formatName = (): void => {
     const {nextTemplate} = this.state
-    const tempVar = formatName(nextTemplate.tempVar)
+
+    let tempVar = formatName(nextTemplate.tempVar)
+
+    if (tempVar === '::') {
+      tempVar = ''
+    }
 
     this.setState({nextTemplate: {...nextTemplate, tempVar}})
   }

ui/src/tempVars/constants/index.ts

@@ -62,7 +62,7 @@ export const DEFAULT_TEMPLATES: DefaultTemplates = {
   [TemplateType.Databases]: () => {
     return {
       id: uuid.v4(),
-      tempVar: ':my-databases:',
+      tempVar: '',
       values: [
         {
           value: '_internal',
@@ -80,7 +80,7 @@ export const DEFAULT_TEMPLATES: DefaultTemplates = {
   [TemplateType.Measurements]: () => {
     return {
       id: uuid.v4(),
-      tempVar: ':my-measurements:',
+      tempVar: '',
       values: [],
       type: TemplateType.Measurements,
       label: '',
@@ -93,7 +93,7 @@ export const DEFAULT_TEMPLATES: DefaultTemplates = {
   [TemplateType.CSV]: () => {
     return {
       id: uuid.v4(),
-      tempVar: ':my-values:',
+      tempVar: '',
       values: [],
       type: TemplateType.CSV,
       label: '',
@@ -103,7 +103,7 @@ export const DEFAULT_TEMPLATES: DefaultTemplates = {
   [TemplateType.TagKeys]: () => {
     return {
       id: uuid.v4(),
-      tempVar: ':my-tag-keys:',
+      tempVar: '',
       values: [],
       type: TemplateType.TagKeys,
       label: '',
@@ -115,7 +115,7 @@ export const DEFAULT_TEMPLATES: DefaultTemplates = {
   [TemplateType.FieldKeys]: () => {
     return {
       id: uuid.v4(),
-      tempVar: ':my-field-keys:',
+      tempVar: '',
       values: [],
       type: TemplateType.FieldKeys,
       label: '',
@@ -127,7 +127,7 @@ export const DEFAULT_TEMPLATES: DefaultTemplates = {
   [TemplateType.TagValues]: () => {
     return {
       id: uuid.v4(),
-      tempVar: ':my-tag-values:',
+      tempVar: '',
       values: [],
       type: TemplateType.TagValues,
       label: '',