Insert flux function at or below cursor line

CHANGELOG.md

@@ -2,6 +2,7 @@
 ### Bug Fixes
 1. [#5110](https://github.com/influxdata/chronograf/pull/5110): Fix the input for line controls in visualization options.
 1. [#5111](https://github.com/influxdata/chronograf/pull/5111): Stop scrollbars from covering text in flux editor
+1. [#5114](https://github.com/influxdata/chronograf/pull/5114): Insert flux function near cursor in flux editor
 
 ## v1.7.8 [2019-02-08]
 ### Bug Fixes

ui/src/flux/components/FluxEditor.tsx

@@ -1,5 +1,6 @@
 // Libraries
 import React, {PureComponent} from 'react'
+import {Position} from 'codemirror'
 
 // Components
 import FluxScriptEditor from 'src/flux/components/FluxScriptEditor'
@@ -16,6 +17,7 @@ interface Props {
   onChangeScript: (draftScript: string) => void
   onSubmitScript: () => void
   onShowWizard: () => void
+  onCursorChange?: (position: Position) => void
 }
 
 class FluxEditor extends PureComponent<Props> {
@@ -28,6 +30,7 @@ class FluxEditor extends PureComponent<Props> {
       onChangeScript,
       onSubmitScript,
       onShowWizard,
+      onCursorChange,
     } = this.props
 
     return (
@@ -39,6 +42,7 @@ class FluxEditor extends PureComponent<Props> {
           suggestions={suggestions}
           onChangeScript={onChangeScript}
           onSubmitScript={onSubmitScript}
+          onCursorChange={onCursorChange}
         >
           {script.trim() === '' && (
             <div className="flux-script-wizard--bg-hint">

ui/src/flux/components/FluxScriptEditor.tsx

@@ -1,6 +1,6 @@
 import React, {PureComponent, MouseEvent} from 'react'
 import {Controlled as ReactCodeMirror, IInstance} from 'react-codemirror2'
-import {EditorChange, LineWidget} from 'codemirror'
+import {EditorChange, LineWidget, Position} from 'codemirror'
 import {ShowHintOptions} from 'src/types/codemirror'
 import {ErrorHandling} from 'src/shared/decorators/errors'
 import {OnChangeScript, Suggestion} from 'src/types/flux'
@@ -24,6 +24,7 @@ interface Props {
   onChangeScript: OnChangeScript
   onSubmitScript: () => void
   suggestions: Suggestion[]
+  onCursorChange?: (position: Position) => void
 }
 
 interface Widget extends LineWidget {
@@ -32,6 +33,7 @@ interface Widget extends LineWidget {
 
 interface State {
   script: string
+  cursorPosition: Position
 }
 
 interface EditorInstance extends IInstance {
@@ -51,6 +53,7 @@ class FluxScriptEditor extends PureComponent<Props, State> {
     super(props)
     this.state = {
       script: props.script,
+      cursorPosition: null,
     }
   }
 
@@ -108,12 +111,21 @@ class FluxScriptEditor extends PureComponent<Props, State> {
           onTouchStart={this.onTouchStart}
           editorDidMount={this.handleMount}
           onKeyUp={this.handleKeyUp}
+          onCursor={this.handleCursorChange}
         />
         {children}
       </div>
     )
   }
 
+  private handleCursorChange = (__: IInstance, position: Position) => {
+    const {onCursorChange} = this.props
+
+    if (onCursorChange) {
+      onCursorChange(position)
+    }
+  }
+
   private handleMouseEnter = (e: MouseEvent<HTMLDivElement>) => {
     const {width, height} = e.currentTarget.getBoundingClientRect()
     const {width: prevWidth, height: prevHeight} = this.containerDimensions

ui/src/flux/components/flux_functions_toolbar/FluxFunctionsToolbar.tsx

@@ -9,7 +9,7 @@ import SearchBar from 'src/flux/components/flux_functions_toolbar/SearchBar'
 import FancyScrollbar from 'src/shared/components/FancyScrollbar'
 
 // Constants
-import {FUNCTIONS, FROM, UNION} from 'src/flux/constants/functions'
+import {FUNCTIONS} from 'src/flux/constants/functions'
 
 // Utils
 import {TimeMachineContainer} from 'src/shared/utils/TimeMachineContainer'
@@ -17,20 +17,28 @@ import {TimeMachineContainer} from 'src/shared/utils/TimeMachineContainer'
 // Decorators
 import {ErrorHandling} from 'src/shared/decorators/errors'
 
+interface PassedProps {
+  onInsertFluxFunction: (functionName: string, text: string) => void
+}
+
 interface ConnectedProps {
   script: string
   onUpdateScript: (script: string) => void
 }
 
+type Props = PassedProps & ConnectedProps
+
 interface State {
   searchTerm: string
 }
+
 @ErrorHandling
-class FluxFunctionsToolbar extends PureComponent<ConnectedProps, State> {
-  public constructor(props) {
+class FluxFunctionsToolbar extends PureComponent<Props, State> {
+  public constructor(props: Props) {
     super(props)
     this.state = {searchTerm: ''}
   }
+
   public render() {
     const {searchTerm} = this.state
     return (
@@ -50,7 +58,7 @@ class FluxFunctionsToolbar extends PureComponent<ConnectedProps, State> {
                         key={category}
                         category={category}
                         funcs={funcs}
-                        onClickFunction={this.handleUpdateScript}
+                        onClickFunction={this.handleClickFunction}
                       />
                     )
                   }
@@ -63,32 +71,23 @@ class FluxFunctionsToolbar extends PureComponent<ConnectedProps, State> {
     )
   }
 
+  private handleClickFunction = (
+    fluxFunction: string,
+    funcExample: string
+  ): void => {
+    this.props.onInsertFluxFunction(fluxFunction, funcExample)
+  }
+
   private handleSearch = (searchTerm: string): void => {
     this.setState({searchTerm})
   }
-
-  private handleUpdateScript = (funcName: string, funcExample: string) => {
-    const {script, onUpdateScript} = this.props
-
-    switch (funcName) {
-      case FROM.name: {
-        onUpdateScript(`${script}\n${funcExample}`)
-        return
-      }
-      case UNION.name: {
-        onUpdateScript(`${script.trimRight()}\n\n${funcExample}`)
-        return
-      }
-      default:
-        onUpdateScript(`${script}\n  |> ${funcExample}`)
-    }
-  }
 }
 
-const ConnectedFluxFunctionsToolbar = () => (
+const ConnectedFluxFunctionsToolbar = (props: PassedProps) => (
   <Subscribe to={[TimeMachineContainer]}>
     {(container: TimeMachineContainer) => (
       <FluxFunctionsToolbar
+        {...props}
         script={container.state.draftScript}
         onUpdateScript={container.handleUpdateDraftScript}
       />

ui/src/flux/helpers/scriptInsertion.ts

@@ -0,0 +1,82 @@
+import {Position} from 'codemirror'
+
+// Constants
+import {FROM, UNION} from 'src/flux/constants/functions'
+
+const rejoinScript = (scriptLines: string[]): string => {
+  return scriptLines.join('\n')
+}
+
+const insertAtLine = (
+  lineNumber: number,
+  scriptLines: string[],
+  textToInsert: string,
+  insertOnSameLine?: boolean
+): string => {
+  const front = scriptLines.slice(0, lineNumber)
+
+  const backStartIndex = insertOnSameLine ? lineNumber + 1 : lineNumber
+  const back = scriptLines.slice(backStartIndex)
+
+  const updated = [...front, textToInsert, ...back]
+
+  return rejoinScript(updated)
+}
+
+const getInsertLineNumber = (
+  currentLineNumber: number,
+  scriptLines: string[]
+): number => {
+  const currentLine = scriptLines[currentLineNumber]
+
+  // Insert on the current line if its an empty line
+  if (!currentLine.trim()) {
+    return currentLineNumber
+  }
+
+  return currentLineNumber + 1
+}
+
+const formatFunctionForInsert = (funcName: string, fluxFunction: string) => {
+  switch (funcName) {
+    case FROM.name:
+    case UNION.name: {
+      return `\n${fluxFunction}`
+    }
+    default:
+      return `  |> ${fluxFunction}`
+  }
+}
+
+const getCursorPosition = (insertLineNumber, formattedFunction): Position => {
+  const endOfLine = formattedFunction.length - 1
+
+  return {line: insertLineNumber, ch: endOfLine}
+}
+
+export const insertFluxFunction = (
+  currentLineNumber: number,
+  currentScript: string,
+  functionName: string,
+  fluxFunction: string
+): {updatedScript: string; cursorPosition: Position} => {
+  const scriptLines = currentScript.split('\n')
+  const insertLineNumber = getInsertLineNumber(currentLineNumber, scriptLines)
+  const insertOnSameLine = currentLineNumber === insertLineNumber
+
+  const formattedFunction = formatFunctionForInsert(functionName, fluxFunction)
+
+  const updatedScript = insertAtLine(
+    insertLineNumber,
+    scriptLines,
+    formattedFunction,
+    insertOnSameLine
+  )
+
+  const updatedCursorPosition = getCursorPosition(
+    insertLineNumber,
+    formattedFunction
+  )
+
+  return {updatedScript, cursorPosition: updatedCursorPosition}
+}

ui/src/shared/components/TimeMachine/FluxQueryMaker.tsx

@@ -1,6 +1,7 @@
 // Libraries
 import React, {PureComponent} from 'react'
 import {Subscribe} from 'unstated'
+import {Position} from 'codemirror'
 
 // Components
 import SchemaExplorer from 'src/flux/components/SchemaExplorer'
@@ -20,6 +21,7 @@ import DefaultDebouncer, {Debouncer} from 'src/shared/utils/debouncer'
 import {TimeMachineContainer} from 'src/shared/utils/TimeMachineContainer'
 import {parseError} from 'src/flux/helpers/scriptBuilder'
 import {getSuggestions} from 'src/flux/helpers/suggestions'
+import {insertFluxFunction} from 'src/flux/helpers/scriptInsertion'
 
 // Types
 import {NotificationAction, Source} from 'src/types'
@@ -56,6 +58,7 @@ interface State {
 class FluxQueryMaker extends PureComponent<Props, State> {
   private debouncer: Debouncer = new DefaultDebouncer()
   private getAST = restartable(getAST)
+  private cursorPosition: Position
 
   public constructor(props: Props) {
     super(props)
@@ -122,6 +125,7 @@ class FluxQueryMaker extends PureComponent<Props, State> {
             onChangeScript={this.handleChangeDraftScript}
             onSubmitScript={this.handleSubmitScript}
             onShowWizard={this.handleShowWizard}
+            onCursorChange={this.handleCursorPosition}
           />
         ),
       },
@@ -130,7 +134,11 @@ class FluxQueryMaker extends PureComponent<Props, State> {
         size: rightSize,
         headerButtons: [],
         menuOptions: [],
-        render: () => <FluxFunctionsToolbar />,
+        render: () => (
+          <FluxFunctionsToolbar
+            onInsertFluxFunction={this.handleInsertFluxFunction}
+          />
+        ),
         headerOrientation: HANDLE_VERTICAL,
       },
     ]
@@ -152,6 +160,28 @@ class FluxQueryMaker extends PureComponent<Props, State> {
     )
   }
 
+  private handleCursorPosition = (position: Position): void => {
+    this.cursorPosition = position
+  }
+
+  private handleInsertFluxFunction = async (
+    functionName: string,
+    fluxFunction: string
+  ): Promise<void> => {
+    const {draftScript} = this.props
+    const {line} = this.cursorPosition
+
+    const {updatedScript, cursorPosition} = insertFluxFunction(
+      line,
+      draftScript,
+      functionName,
+      fluxFunction
+    )
+    await this.handleChangeDraftScript(updatedScript)
+
+    this.handleCursorPosition(cursorPosition)
+  }
+
   private handleSubmitScript = () => {
     const {
       onChangeScript,