LineChartProps.md

Line Chart props

Basic props

Prop	Type	Description	Default value
data	Array	An item object represents a point in the line chart. It is described in the next table.	_
data2	Array	Second set of dataPoint for the second line	_
data3	Array	Third set of dataPoint for the third line	_
data4	Array	Fourth set of dataPoint for the fourth line	_
data5	Array	Fifth set of dataPoint for the third line	_
dataSet	Array	Array of data sets (used instead of using data2, data3, data4 etc)	_
width	number	Width of the Bar chart	width of the parent
height	number	Height of the Bar chart (excluding the bottom label)	200
overflowTop	number	Extra space at the top of the chart to make room for dataPointText	0
overflowBottom	number	Extra space at the bottom of the chart to make room for dataPoints or dataPointText	dataPointRadius
maxValue	number	Maximum value shown in the Y axis	200
mostNegativeValue	number	The most negative value shown in the Y axis (to be used only if the data set has negative values too)	_
noOfSections	number	Number of sections in the Y axis	10
noOfSectionsBelowXAxis	number	Number of sections in the Y axis below X axis (in case the data set has negative values too)	0
stepValue	number	Value of 1 step/section in the Y axis	20
stepHeight	number	Height of 1 step/section in the Y axis	20
negativeStepValue	number	Value of 1 step/section in the Y axis for negative values (in the 4th quadrant)	stepValue
negativeStepHeight	number	Height of 1 step/section in the Y axis for negative values (in the 4th quadrant)	stepHeight
spacing	number	Distance between 2 consecutive points in the Line chart	50
adjustToWidth	boolean	When set to true, it auto computes the spacing value to fit the Line chart in the available width	false
backgroundColor	ColorValue	Background color of the Bar chart	_
sectionColors	ColorValue	Background color of the horizontal sections of the chart	backgroundColor
scrollref	any	ref object that can be used to control the horizontal ScrollView inside which the chart is rendered	React.useRef()
scrollToIndex	number	scroll to a particular index on chart load	_
disableScroll	boolean	To disable horizontal scroll	false
showScrollIndicator	boolean	To show horizontal scroll indicator	false
indicatorColor	String	(iOS only) The color of the scroll indicators - ('black', 'white' or 'default')	default
nestedScrollEnabled	boolean	Useful when the chart is used inside a horizontal ScrollView (without this, the chart's scrolling is compromised)	false
isAnimated	boolean	To show animated Line or Area Chart. Animation occurs when the chart load for the first time	false
animateOnDataChange	boolean	To show animation on change in data. A smooth transition takes place between the old and new line	false
onDataChangeAnimationDuration	number	Duration (milliseconds) in which the transition animation takes place on a change in data	400
onPress	Function	The callback function that handles the press event. item and index are received as props	_
scrollToEnd	boolean	When set to true, the chart automatically scrolls to the rightmost data point	false
scrollAnimation	boolean	When set to true, scroll animation is visible when the chart automatically scrolls to the rightmost data point	true
scrollEventThrottle	number	(only for iOS) see https://reactnative.dev/docs/scrollview#scrolleventthrottle-ios	0
onScroll	Function	callback function called when the chart is scrolled horizontally	_
onMomentumScrollEnd	Function	callback function called when scroll is completed	_
initialSpacing	number	distance of the first data point from the Y axis	20
endSpacing	number	distance/padding left at the end of the line chart	adjustWidth ? 0 : 20
stepChart	boolean	If set true, renders a step chart	false
stepChart1	boolean	If set true, renders a step chart for 1st data set	stepChart
stepChart2	boolean	If set true, renders a step chart for 2nd data set	stepChart
stepChart3	boolean	If set true, renders a step chart for 3rd data set	stepChart
stepChart4	boolean	If set true, renders a step chart for 4th data set	stepChart
stepChart5	boolean	If set true, renders a step chart for 5th data set	stepChart
edgePosition	EdgePosition	Used only for stepCharts to specify the edge positions of the steps	EdgePosition.AFTER_DATA_POINT
onlyPositive	boolean	when this prop is truthy, it converts negative values to 0	false
onBackgroundPress	Function	Callback function called on pressing the chart body (outside of the are under chart in case of area charts)	_

---

enum EdgePosition {
  AFTER_DATA_POINT,
  BEFORE_DATA_POINT,
  AROUND_DATA_POINT,
}

dataSet : Dynamic number of lines

Version 1.3.19 onwards, we support dynamic number of lines with the help of the dataSet prop. You can pass an array of data instead of using data, data2, data3 etc.

type DataSet = {
  data: Array<lineDataItem>;
  zIndex?: number;
  thickness?: number;
  strokeDashArray?: Array<number>;
  areaChart?: boolean;
  stepChart?: boolean;
  startIndex?: number;
  endIndex?: number;
  color?: string;
  hideDataPoints?: boolean;
  dataPointsHeight?: number;
  dataPointsWidth?: number;
  dataPointsRadius?: number;
  dataPointsColor?: string;
  dataPointsShape?: string;
  startFillColor?: string;
  endFillColor?: string;
  startOpacity?: number;
  endOpacity?: number;
  textFontSize?: number;
  textColor?: string;
  showArrow?: boolean;
  arrowConfig?: arrowConfigType;
  curved?: boolean;
  curvature?: number;
  curveType?: CurveType;
  lineSegments?: Array<LineSegment>;
  isSecondary?: boolean;
  hidePointers?: boolean;
};

Alert!
These props are correlated:

1. maxValue
2. noOfSections
3. stepValue

They must follow the relation:

maxValue = noOfSections * stepValue;

So, all the three must be used together. Using any 1 or 2 of them may produce absurd results

---

Item description (lineDataItem)

Key	Value type	Description
value	number	Value of the item representing representing its position
onPress	function	Function called on pressing the data point
label	string	Label text appearing under the X axis
labelTextStyle	object	Style object for the label text appearing under the X axis
labelComponent	Function	custom label component appearing under the X axis
secondaryLabel	string	Label text appearing above the secondary X-axis (at the top of the chart)
secondaryLabelComponent	Component	Custom label component appearing above the secondary X-axis (at the top of the chart)
secondaryLabelTextStyle	object	Style object for the label text of secondary X-axis (at the top of the chart)
yAxisLabelText	string	Y axis label text
dataPointText	string	Text appearing near the data points
textShiftX	number	To shift the dataPointText text horizontally
textShiftY	number	To shift the dataPointText text vertically
textColor	ColorValue	Color of the dataPointText
textFontSize	number	Font size of the dataPointText
spacing	number	Distance between 2 consecutive points in the Line chart
dataPointHeight	number	Height of the data point (when data point's shape is rectangular)
dataPointWidth	number	Width of the data point (when data point's shape is rectangular)
dataPointRadius	number	Radius of the data point (when data points' shape is circular)
dataPointColor	ColorValue	Color of the data point
dataPointShape	string	Shape of the data point (rectangular or circular) defaults to circular
hideDataPoint	boolean	To hide the data point
showVerticalLine	boolean	When set to true, a vertical line will be displayed along that data point
verticalLineUptoDataPoint	boolean	When set to true, it sets the height of the vertical line upto the corresponding data point
verticalLineColor	ColorValue	Color of the vertical Line displayed along the data point
verticalLineThickness	number	Thickness of the vertical Line displayed along the data point
dataPointLabelWidth	number	width of the label shown beside a data point
dataPointLabelShiftX	number	horizontal shift of a label from its corresponding data point
dataPointLabelShiftY	number	vertical shift of a label from its corresponding data point
dataPointLabelComponent	Function	custom component rendered above a data point
focusedDataPointLabelComponent	Function	custom component rendered above a data point only when focused/selected (when the user presses)
showStrip	boolean	To show a vertical strip along the data point (even if it's not focused/selected)
stripHeight	number	Height of the vertical strip that becomes visible on pressing the corresponding area of the chart, or when showStrip is set to true
stripWidth	number	Width of the vertical strip that becomes visible on pressing the corresponding area of the chart, or when showStrip is set to true
stripColor	ColorValue	Color of the vertical strip that becomes visible on pressing the corresponding area of the chart, or when showStrip is set to true
stripOpacity	number	Opacity of the vertical strip that becomes visible on pressing the corresponding area of the chart, or when showStrip is set to true
stripStrokeDashArray	Array	Array of 2 numbers denoting the dashWidth and dashGap of the vertical strip
pointerShiftX	number	Shifts the pointer for that item horizontally by given quantity (used only when pointerConfig prop is passed)
pointerShiftY	number	Shifts the pointer for that item vertically by given quantity (used only when pointerConfig prop is passed)
hidePointer	boolean	Used to hide the pointer for current item

Alert
When you are using the dataPointLabelComponent, make sure to provide the dataPointsHeight and dataPointsWidth values too (either in the corresponding item object, or directly as a props of the component). Otherwise the data points might appear shifted from their intended positions.

---

Pagination related props

Prop	Type	Description	Default value
onEndReached	Function	Callback function called when the chart is scrolled upto end	_
onStartReached	Function	Callback function called when the chart is scrolled upto start	_
endReachedOffset	number	distance before end of scroll when onEndReached should be triggered	80

---

Axes and rules related props

Prop	Type	Description	Default value
xAxisLength	number	X axis length	width of the chart
xAxisColor	ColorValue	X axis color	black
xAxisThickness	number	X axis thickness	1
xAxisType	RuleType	solid or dotted/dashed	solid
yAxisColor	ColorValue	Y axis color	black
yAxisThickness	number	Y axis thickness	1
yAxisLabelWidth	number	Width of the Y axis Label container	35
yAxisTextStyle	object	Style object for the Y axis text style	_
yAxisTextNumberOfLines	number	Number of lines for y axis label text	1
yAxisLabelContainerStyle	object	Style object for the Y axis label container	_
trimYAxisAtTop	boolean	Removes the extra length of the Y axis from the top	false
yAxisExtraHeight	number	Extra length of Y axis at the top	(height / 20)
yAxisOffset	number	Starting value on Y Axis	0
horizontalRulesStyle	object	Style object for the horizontal rules container	_
showFractionalValues	boolean	Allow fractional values for the Y axis label	false
roundToDigits	number	Rounds the y axis values to given number of digits after decimal point	1
yAxisLabelPrefix	String	The String prepended to the y axis label text (for example- '$')	''
yAxisLabelSuffix	String	The String appended to the y axis label text	''
hideYAxisText	boolean	To hide Y axis label text	false
formatYLabel	(label: string) => string	a callback function that takes the label generated by the library and modifies it.	_
yAxisSide	yAxisSides	Tells which side of the chart, should the y axis be present, defaults to yAxisSides.LEFT	yAxisSides.LEFT
rulesLength	number	Length of the horizontal rules	width of the chart
rulesColor	ColorValue	Color of the horizontal rules	lightgray
rulesThickness	number	Thickness of the horizontal rules	1
hideRules	boolean	To hide the horizontal rules	false
rulesType	RuleType	solid or dotted/dashed	solid
dashWidth	number	width of each dash	4
dashGap	number	gap between 2 dashes	8
rulesConfigArray	Array	Array of rulesConfig objects, used to customise the properties (like color, type etc) of specific rules	_
showReferenceLine1	boolean	show reference line	false
referenceLine1Config	referenceConfigType	properties of reference line like thickness, color etc (described below the table)	_
referenceLine1Position	number	position of reference line	containerHeight / 2
showReferenceLine2	boolean	show second reference line	false
referenceLine2Config	referenceConfigType	properties of reference line like thickness, color etc (described below the table)	_
referenceLine2Position	number	position of second reference line	3*containerHeight / 2
showReferenceLine3	boolean	show third reference line	false
referenceLine3Config	referenceConfigType	properties of reference line like thickness, color etc (described below the table)	_
referenceLine3Position	number	position of third reference line	containerHeight / 2
referenceLinesOverChartContent	boolean	used to render the reference lines over the rest of the chart content.	true
showVerticalLines	boolean	To show vertical lines	false
verticalLinesUptoDataPoint	boolean	To set the height of the vertical lines upto the corresponding data point	false
verticalLinesColor	ColorValue	Color of the vertical lines	lightgray
verticallinesThickness	number	Thickness of the vertical lines	1
verticalLinesHeight	number	Height of the vertical lines	chart height
verticalLinesStrokeDashArray	Array	Array of 2 numbers denoting the dashWidth and dashGap of the lines. Used to render dashed/dotted vertical line	''
verticalLinesShift	number	vertical lines are aligned with data point. Shift them left or right using +ve or -ve value of verticalLinesShift	0
verticalLinesZIndex	number	Z index of the vertical lines	-1
noOfVerticalLines	number	Number of vertical lines displayed	data.length
verticalLinesSpacing	number	Distance between consecutive vertical lines	spacing
verticalLinesStrokeLinecap	'butt' | 'round' | 'square'	Linecap of the vertical lines (see stroke-linecap in svg)	'butt'
showXAxisIndices	boolean	To show the pointers on the X axis	false
xAxisIndicesHeight	number	Height of the pointers on the X axis	2
xAxisIndicesWidth	number	Width of the pointers on the X axis	4
xAxisIndicesColor	ColorValue	Color of the pointers on the X axis	black
showYAxisIndices	boolean	To show the pointers on the Y axis	false
yAxisIndicesHeight	number	Height of the pointers on the Y axis	2
yAxisIndicesWidth	number	Width of the pointers on the Y axis	4
yAxisIndicesColor	ColorValue	Color of the pointers on the X axis	black
yAxisIndicesColor	boolean	To hide axes, rules, labels altogether	false
yAxisLabelTexts	Array	Array of label texts to be displayed along y axis	null
xAxisLabelTexts	Array	Array of label texts to be displayed below x axis	null
xAxisLabelTextStyle	object	Style of label texts to be displayed below x axis	null
xAxisTextNumberOfLines	number	Number of lines for x axis label text	1
xAxisLabelsHeight	number	Height of X axis labels container	xAxisTextNumberOfLines * 18
xAxisLabelsVerticalShift	number	prop to adjust the vertical position of X axis labels (move X axis labels up or down)	0
rotateLabel	boolean	To rotate the X axis labels (by 60deg)	false
hideOrigin	boolean	To hide the y Axis label at origin (i.e. 0)	false
secondaryYAxis	secondaryYAxisType	displays and controls the properties of the secondary Y axis on the right side	null
secondaryData	Array of items	the secondary data that will be rendered along the secondary Y axis	undefined
secondaryLineConfig	secondaryLineConfigType	properties of the secondary data line (secondaryLineConfigType is described below)	values of primary Line
secondaryXAxis	XAxisConfig	properties of the secondary X-axis (appearing at the top of the chart)	values of the primary X-axis

Note If you are setting yAxisSide to yAxisSide.RIGHT, make sure to specify the width of the chart, using the width prop

type RuleType = 'solid' | 'dashed' | 'dotted';

type RulesConfig = {
  rulesLength?: number;
  rulesColor?: ColorValue;
  rulesThickness?: number;
  rulesType?: RuleType;
  dashWidth?: number;
  dashGap?: number;
};

ReferenceConfigType has following properties-

type referenceConfigType = {
  thickness: number;
  width: number;
  color: ColorValue | String | any;
  type: ruleTypes;
  dashWidth: number;
  dashGap: number;
  labelText: String;
  labelTextStyle: object;
  zIndex: number; // default 1
  resetPointerOnDataChange: boolean; // default true
};

XAxisConfig has following properties-

type XAxisConfig {
  thickness?: number
  color?: ColorValue
  labelsDistanceFromXaxis?: number
  labelsHeight?: number
  labelsTextStyle?: any
  labelTexts?: string[]
}

---

secondaryYAxis

Use this prop to render a secondary Y axis on the right side of the chart. secondaryYAxis is an object of type of secondaryYAxisType You can control the properties of secodary Y axis by passing an object of properties. Following is the type definition of the secondaryYAxisType object

type secondaryYAxisType = {
  noOfSections?: number;
  maxValue?: number;
  mostNegativeValue?: number;
  stepValue?: number;
  stepHeight?: number;
  showFractionalValues?: boolean;
  roundToDigits?: number;

  showYAxisIndices?: boolean;
  yAxisIndicesHeight?: number;
  yAxisIndicesWidth?: number;
  yAxisIndicesColor?: ColorValue;

  yAxisSide?: yAxisSides;
  yAxisOffset?: number;
  yAxisThickness?: number;
  yAxisColor?: ColorValue;
  yAxisLabelContainerStyle?: any;
  yAxisLabelTexts: Array<string> | undefined;
  yAxisTextStyle?: any;
  yAxisTextNumberOfLines?: number;
  yAxisLabelWidth?: number;
  hideYAxisText?: boolean;
  yAxisLabelPrefix?: string;
  yAxisLabelSuffix?: string;
  hideOrigin?: boolean;
  formatYLabel?: (label: string) => string;
};

All the properties are optional. If you don't set a property in the secondaryYAxis, it takes the default values from the primary Y axis.

secondaryData

We can render a chart with two lines/curves, one corresponding to the left Y axis and the other corresponding to the right Y axis. Here is an example-

Here we have a normal Y axis in orange color and an orange data line corresponding to it. Also the blue color Y axis on the right is the secondary Y axis and the blue line corresponds to to that axis. This is achived by using the secondaryYAxis and the secondaryData props.

secondaryLineConfig

Properties of the secondary like color, thickness, curve, strokeWidth, startIndex, endIndex can be controlled using secondaryLineConfig. Below is the list of properties with their types.

type secondaryLineConfigType = {
  zIndex?: number;
  curved?: boolean;
  curvature: number;
  curveType: CurveType; //CurveType is an enum defined below
  areaChart?: boolean;
  color?;
  ColorValue;
  thickness?: number;
  zIndex1?: number;
  strokeDashArray?: Array<number>;
  startIndex?: number;
  endIndex?: number;
  hideDataPoints?: boolean;
  dataPointsHeight?: number;
  dataPointsWidth?: number;
  dataPointsRadius?: number;
  dataPointsColor?: string;
  dataPointsShape?: string;
  showValuesAsDataPointsText?: boolean;
  startFillColor?: string;
  endFillColor?: string;
  startOpacity?: number;
  endOpacity?: number;
  textFontSize?: number;
  textColor?: string;
  showArrow?: boolean;
  arrowConfig?: arrowConfigType;
  spacing?: number;
};

CurveType -

enum CurveType {
  CUBIC,
  QUADRATIC,
}

All the properties of secondaryLineConfig are optional. Properties not provided in the secondaryLineConfig get their default values from the primary (or first) line.

Line related props

Prop	Type	Description	Default value
curved	boolean	To show curved line joining the data points	false
curvature	number	A number between 0 to 1 that controls the curvature of the cubic bezier curve	0.2
curveType	CurveType	Type of the curve- cubic or quadratic	CurveType.CUBIC
color	ColorValue	Color of the lines joining the data points	black
color1	ColorValue	Color of the lines joining the first set of data points	color (from props)
color2	ColorValue	Color of the lines joining the second set of data points	color (from props)
color3	ColorValue	Color of the lines joining the third set of data points	color (from props)
color4	ColorValue	Color of the lines joining the fourth set of data points	color (from props)
color5	ColorValue	Color of the lines joining the fifth set of data points	color (from props)
thickness	number	Thickness of the lines joining the data points	2
thickness1	number	Thickness of the lines joining the first set of data points	thickness (from props)
thickness2	number	Thickness of the lines joining the second set of data points	thickness (from props)
thickness3	number	Thickness of the lines joining the third set of data points	thickness (from props)
thickness4	number	Thickness of the lines joining the fourth set of data points	thickness (from props)
thickness5	number	Thickness of the lines joining the fifth set of data points	thickness (from props)
spacing1	number	Distance between 2 consecutive points in the first line	spacing (from props)
spacing2	number	Distance between 2 consecutive points in the second line	spacing (from props)
spacing3	number	Distance between 2 consecutive points in the third line	spacing (from props)
spacing4	number	Distance between 2 consecutive points in the fourth line	spacing (from props)
spacing5	number	Distance between 2 consecutive points in the fifth line	spacing (from props)
zIndex1	number	zIndex of the lines joining the first set of data points	0
zIndex2	number	zIndex of the lines joining the second set of data points	0
zIndex3	number	zIndex of the lines joining the third set of data points	0
zIndex4	number	zIndex of the lines joining the fourth set of data points	0
zIndex5	number	zIndex of the lines joining the fifth set of data points	0
strokeDashArray	Array	Array of 2 numbers denoting the dashWidth and dashGap of the lines. Used to render dashed/dotted line chart	undefined
strokeDashArray1	Array	Array of 2 numbers denoting the dashWidth and dashGap of line1. Used to render dashed/dotted line chart	undefined OR strokeDashArray
strokeDashArray2	Array	Array of 2 numbers denoting the dashWidth and dashGap of line2. Used to render dashed/dotted line chart	undefined OR strokeDashArray
strokeDashArray3	Array	Array of 2 numbers denoting the dashWidth and dashGap of line3. Used to render dashed/dotted line chart	undefined OR strokeDashArray
strokeDashArray4	Array	Array of 2 numbers denoting the dashWidth and dashGap of line4. Used to render dashed/dotted line chart	undefined OR strokeDashArray
strokeDashArray5	Array	Array of 2 numbers denoting the dashWidth and dashGap of line5. Used to render dashed/dotted line chart	undefined OR strokeDashArray
lineSegments	Array	Array of objects used to customize segments (parts) of line	_
lineSegments2	Array	Array of objects used to customize segments (parts) of line2	_
lineSegments3	Array	Array of objects used to customize segments (parts) of line3	_
lineSegments4	Array	Array of objects used to customize segments (parts) of line4	_
lineSegments5	Array	Array of objects used to customize segments (parts) of line5	_
highlightedRange	HighlightedRange	renders the parts of lines lying in a given data range with a different style (color, thickness,type)	_
startIndex	number	Start index for data line (used to display data lines having breaks)	0
startIndex1	number	Start index for data line 1 (used to display data lines having breaks)	0
startIndex2	number	Start index for data line 2 (used to display data lines having breaks)	0
startIndex3	number	Start index for data line 3 (used to display data lines having breaks)	0
startIndex4	number	Start index for data line 4 (used to display data lines having breaks)	0
startIndex5	number	Start index for data line 5 (used to display data lines having breaks)	0
endIndex	number	End index for data line (used to display data lines having breaks)	data.length -1
endIndex1	number	End index for data line 1 (used to display data lines having breaks)	data1.length -1
endIndex2	number	End index for data line 2 (used to display data lines having breaks)	data2.length -1
endIndex3	number	End index for data line 3 (used to display data lines having breaks)	data3.length -1
endIndex4	number	End index for data line 4 (used to display data lines having breaks)	data4.length -1
endIndex5	number	End index for data line 5 (used to display data lines having breaks)	data5.length -1
lineGradient	boolean	this prop is used to render the line with a gradient blend of colors	false
lineGradientComponent	Function	this prop defines the svg gradient that should be applied to the line (requires lineGradient to be truthy)	null
lineGradientId	string	id of the (needed along with lineGradientComponent prop)	_
lineGradientDirection	string	'vertical'/'horizontal'	'vertical'
lineGradientStartColor	string	Start gradient color for the line (requires lineGradient to be truthy)	'lightgreen'
lineGradientEndColor	string	End gradient color for the line (requires lineGradient to be truthy)

An example of lineGradientComponent

lineGradientId='ggrd' // lineGradientId is required while using lineGradientComponent
lineGradientComponent={()=>{
  return(
    <LinearGradient
      id="ggrd" // same as lineGradientId
      x1="0"
      y1="0"
      x2={'0'}
      y2={'1'}>
      <Stop
        offset="0"
        stopColor={'blue'}
      />
      <Stop
        offset="1"
        stopColor={'yellow'}
      />
    </LinearGradient>
  );
}}

LineSegment

type LineSegment = {
  startIndex: number; // required
  endIndex: number; // required
  color?: string | ColorValue;
  thickness?: number;
  strokeDashArray?: Array<number>;
};

---

Interpolation

If some data items have null or undefined values, their values get auto-assigned by the library. This is done by interpolating. To stop this, set interpolateMissingValues={false}. When you set interpolateMissingValues to false, the nullish values will not rendered, thus the line (or curve) will be broken into parts.

Interpolation related props

Prop	Type	Description	Default value
interpolateMissingValues	boolean	auto-assigns values to data items that have nullish (null or undefined) values by interpolation	true
showDataPointsForMissingValues	boolean	data points are hidden by default for interpolated values, to show them, use this props	false
extrapolateMissingValues	boolean	auto-assigns values to data items that have nullish values in the start and end of chart	true
onlyPositive	boolean	when this prop is truthy, it converts negative values to 0 (possibly obtained by interpolation)	false

Note: extrapolateMissingValues will NOT work if interpolateMissingValues is set to false. Extrapolation will work only if interpolation is enabled.

Interpolation strategy

If all values are nullish, render an empty chart. If all except one value is nullish, make all nullish values equal to the non-nullish value.

otherwise

If a value is nullish, we look at the previous and next numeric values.

1. If we have both, we find the slope between them and compute the missing values.
2. If we don't have any numeric values ahead, but we have numeric values in the previous section, we find the slope between the last two numeric values in the previous section and compute the remaining values. This will not work if extrapolateMissingValues is set to false.
3. If we don't have any numeric values in the previous section, but we have numeric values ahead, we find the slope between the next two numeric values in the ahead section and compute the remaining values. This will not work if extrapolateMissingValues is set to false.

---

HighlightedRange

An example of HighlightedRange on Stack overflow- https://stackoverflow.com/questions/70406903/different-colors-line-chart-with-react-native-chart-kit

type HighlightedRange = {
  from: number;
  to: number;
  color?: string | ColorValue;
  thickness?: number;
  strokeDashArray?: Array<number>;
};

The arrow

Some Line charts have an arrow at the end of the line. Here's an example-

To display the arrrow at the end of the line, just pass the showArrows or showArrow{n} prop. The properties of the arrow can controlled with the arrowConfig prop.

Understanding the arrow-

Prop	Type	Description	Default value
showArrows	boolean	To show an arrow at the end of each data line	false
arrowConfig	arrowType	Object describing the properties of the arrows like length, width, strokeWidth, strokeColor, fillColor	defaultArrowConfig
showArrow1	boolean	To show an arrow at the end of the first data line	false
arrowConfig1	arrowType	Object describing the properties of the first arrow	defaultArrowConfig
showArrow2	boolean	To show an arrow at the end of the second data line	false
arrowConfig2	arrowType	Object describing the properties of the second arrow	defaultArrowConfig
showArrow3	boolean	To show an arrow at the end of the third data line	false
arrowConfig3	arrowType	Object describing the properties of the third arrow	defaultArrowConfig
showArrow4	boolean	To show an arrow at the end of the fourth data line	false
arrowConfig4	arrowType	Object describing the properties of the fourth arrow	defaultArrowConfig
showArrow5	boolean	To show an arrow at the end of the fifth data line	false
arrowConfig5	arrowType	Object describing the properties of the fifth arrow	defaultArrowConfig

The arrowConfig has the properties allowed by the arrowType-

type arrowType = {
  length?: number;
  width?: number;
  strokeWidth?: number;
  strokeColor?: string;
  fillColor?: string;
  showArrowBase?: boolean;
};

The default values of these properties are-

defaultArrowConfig = {
  length: 10,
  width: 10,
  strokeWidth: thickness1,
  strokeColor: color1,
  fillColor: 'none',
  showArrowBase: true,
};

showArrowBase

The arrow base can be understood with the pic below-

The default value of showArrowBase is true. To fill the arrow with fillColor, it is mandatory to have showArrowBase true. The arrow can't be filled if it's baseless.

---

Data points related props

Prop	Type	Description	Default value
hideDataPoints	boolean	To hide data points	false
dataPointsHeight	number	Height of data points (when data points' shape is rectangular)	4
dataPointsWidth	number	Width of data points (when data points' shape is rectangular)	4
dataPointsRadius	number	Radius of data points (when data points' shape is circular)	3
dataPointsColor	ColorValue	Color of the data points	black
dataPointsShape	string	Shape of the data points ('rectangular' or 'circular')	'circular'
hideDataPoints1	boolean	To hide data points for the first set of data	false
dataPointsHeight1	number	Height of data points for the first dataset (when data points' shape is rectangular)	4
dataPointsWidth1	number	Width of data points for the first dataset (when data points' shape is rectangular)	4
dataPointsRadius1	number	Radius of data points for the first dataset (when data points' shape is circular)	3
dataPointsColor1	ColorValue	Color of data points for the first dataset	black
dataPointsShape1	string	Shape of data points for the first dataset	'circular'
hideDataPoints2	boolean	To hide data points for the second set of data	false
dataPointsHeight2	number	Height of data points for the second dataset (when data points' shape is rectangular)	4
dataPointsWidth2	number	Width of data points for the second dataset (when data points' shape is rectangular)	4
dataPointsRadius2	number	Radius of data points for the second dataset (when data points' shape is circular)	3
dataPointsColor2	ColorValue	Color of data points for the second dataset	blue
dataPointsShape2	string	Shape of data points for the second dataset ('rectangular' or 'circular')	'circular'
hideDataPoints3	boolean	To hide data points for the third set of data	false
dataPointsHeight3	number	Height of data points for the third dataset (when data points' shape is rectangular)	4
dataPointsWidth3	number	Width of data points for the third dataset (when data points' shape is rectangular)	4
dataPointsRadius3	number	Radius of data points for the third dataset (when data points' shape is circular)	3
dataPointsColor3	ColorValue	Color of data points for the third dataset	red
dataPointsShape3	string	Shape of data points for the third dataset ('rectangular' or 'circular')	'circular'
hideDataPoints4	boolean	To hide data points for the fourth set of data	false
dataPointsHeight4	number	Height of data points for the fourth dataset (when data points' shape is rectangular)	4
dataPointsWidth4	number	Width of data points for the fourth dataset (when data points' shape is rectangular)	4
dataPointsRadius4	number	Radius of data points for the fourth dataset (when data points' shape is circular)	3
dataPointsColor4	ColorValue	Color of data points for the fourth dataset	black
dataPointsShape4	string	Shape of data points for the fourth dataset ('rectangular' or 'circular')	'circular'
hideDataPoints5	boolean	To hide data points for the fifth set of data	false
dataPointsHeight5	number	Height of data points for the fifth dataset (when data points' shape is rectangular)	4
dataPointsWidth5	number	Width of data points for the fifth dataset (when data points' shape is rectangular)	4
dataPointsRadius5	number	Radius of data points for the fifth dataset (when data points' shape is circular)	3
dataPointsColor5	ColorValue	Color of data points for the fifth dataset	black
dataPointsShape5	string	Shape of data points for the fifth dataset ('rectangular' or 'circular')	'circular'
focusedDataPointIndex	number	Index of the focused data point, works only when focusEnabled prop is used	_
focusedDataPointShape	String	Shape of the data points when focused due to press event	item.dataPointsShape OR dataPointsShape
focusedDataPointWidth	number	Width of the data points when focused due to press event	item.dataPointsWidth OR dataPointsWidth
focusedDataPointHeight	number	Height of the data points when focused due to press event	item.dataPointsHeight OR dataPointsHeight
focusedDataPointColor	ColorValue	Color of the data points when focused due to press event	item.dataPointsColor OR dataPointsColor
focusedDataPointRadius	number	Radius of the data points when focused due to press event	item.dataPointsRadius OR dataPointsRadius
focusedCustomDataPoint	Function	Custom data point when focused due to press event	item.customDataPoint OR customDataPoint
textColor	ColorValue	Color of the dataPointText	'black'
textFontSize	number	Font size of the dataPointText	_
textShiftX	number	To shift the dataPointText text horizontally	0
textShiftY	number	To shift the dataPointText text vertically	0
customDataPoint	Function	A callback function to render a custom component as the data points	_
dataPointLabelWidth	number	width of the label shown beside a data point	30
dataPointLabelShiftX	number	horizontal shift of a label from its corresponding data point	0
dataPointLabelShiftY	number	vertical shift of a label from its corresponding data point	0
showValuesAsDataPointsText	boolean	When set to true, the data item value will be shown as a label text near data point	false
pointerColorsForDataSet	ColorValue[]	When using pointers with dataSet, you can set pointer colors on each data line using this array	_

Note customDataPoint prop takes a callback function which accepts 2 parameters-

1. item (object in the data array at the index of the data point)
2. index (index of the data point)

---

pointerConfig

pointerConfig is an object, when passed as a prop, creates a magical effect. It lets the user scroll over chart to move the pointer along the chart. Here is an example-

To enable such kind of csroll effect, just pass the prop pointerConfig. The pointerConfig object has following fields-

type Pointer = {
  height?: number; // default: 0
  width?: number; // default: 0
  radius?: number; // default: 5
  pointerColor?: ColorValue; // default: 'red'
  pointer1Color?: ColorValue; // default: 'red'
  pointer2Color?: ColorValue; // default: 'red'
  pointer3Color?: ColorValue; // default: 'red'
  pointer4Color?: ColorValue; // default: 'red'
  pointer5Color?: ColorValue; // default: 'red'
  secondaryPointerColor?: ColorValue; // default: 'red'
  pointerComponent?: Function; // default: null
  showPointerStrip?: boolean; // default: true
  pointerStripWidth?: number; // default: containerHeight
  pointerStripHeight?: number; // default: 1
  pointerStripColor?: ColorValue; // default: 'black'
  pointerStripUptoDataPoint?: boolean; // default: false
  pointerLabelComponent?: Function; // default: null
  stripOverPointer?: boolean; // default: false
  shiftPointerLabelX?: number; // default: 0
  shiftPointerLabelY?: number; // default: 0
  pointerLabelWidth?: number; // default: 20
  pointerLabelHeight?: number; // default: 20
  autoAdjustPointerLabelPosition?: boolean; // default: false
  pointerVanishDelay?: number; // default: 150
  activatePointersOnLongPress?: boolean; // default: false
  activatePointersDelay?: number; // default: 150
  initialPointerIndex?: number; // default -1
  initialPointerAppearDelay?: number; // if isAnimated, then animationDuration, else 0
  persistPointer?: boolean; // false
  hidePointer1?: boolean; // default: false
  hidePointer2?: boolean; // default: false
  hidePointer3?: boolean; // default: false
  hidePointer4?: boolean; // default: false
  hidePointer5?: boolean; // default: false
  hideSecondaryPointer?: boolean; // default: false
  strokeDashArray?: Array<number>;
  barTouchable?: boolean; //default : false (only applicable to bar charts having pointerConfig)
  pointerEvents?: 'box-none' | 'none' | 'box-only' | 'auto'; // default: "none
  dynamicLegendComponent?: Function; // default null
  dynamicLegendContainerStyle?: Style object; // default null
  horizontalStripConfig?: HorizontalStripConfig; // config for horizontal strip used for crosshair
  hidePointerForMissingValues?: boolean; // false
  hidePointerDataPointForMissingValues?: boolean; // unless explicitly specified, takes the value of hidePointerForMissingValues
};

type HorizontalStripConfig = {
  thickness?: number; // default: pointerStripWidth
  length?: number; // default: width of the chart
  color?: ColorValue; // default: pointerStripColor
  strokeDashArray?: number[]; // default: pointerConfig.strokeDashArray
  horizontalStripUptoDataPoint?: boolean; // default: false
  labelComponent?: Function; // default: null
  labelComponentHeight?: number; // default: 30
  labelComponentWidth?: number;
};

The above properties can be understood with this labelled diagram-

Note If you are using the pointerConfig prop, the scroll will be disabled automatically. This is because, it's difficult to achive both scrolling line and scrolling pointer simultaneously. So if you want to retain the scroll behaviour even after passing the pointerConfig prop, then set the property activatePointersOnLongPress to true inside the pointerConfig object. This will make the pointers visible only after long press. So, before the long press, user can can scroll the line. Once long pressed, scrolling will be disabled until the release of the long press. The duration after which a press event will be considered as long press can be controlled using the activatePointersDelay property inside the pointerConfig object. The default value of activatePointersDelay is 150.

The strokeDashArray property lets us render a dashed/dotted strip along the pointer.

pointerLabelComponent

pointerLabelComponent is a function that returns the component to be rendered as a Label. It takes 3 parameters - 1. an array of items 2. secondaryDataItem 3. pointerIndex. So, if there are multiple data arrays, the parameter items will have the data item corresponding to each data array. If the chart has secondaryData, the parameter secondaryDataItem will have the corresponding item from the secondaryData.

Note If you have a Pressable / Touchable item in your pointerLabelComponent, then you should set pointerEvents to 'auto' inside the pointerConfig object.

getPointerProps

getPointerProps prop can be used to get the current pointer's index, x and y coordinate values. It is a callback function that accepts a single parameter which is an object. This object has following properties-

1. pointerIndex
2. pointerX
3. pointerY

When the chart is pressed, it returns the index of the data point pressed.
When the chart is scrolled after pressing, it returns the index of the data point currently focused.
When the chart is released, it returns the index -1.

pointerColorsForDataSet

When using pointers with dataSet, you can set pointer colors on each data line using the pointerColorsForDataSet which is an array of color values.

dynamicLegendComponent

dynamicLegendComponent is a property inside the pointerConfig prop, very similar to pointerLabelComponent, the only difference is that it is stationary whereas pointerLabelComponent moves as the pointer moves. You can set the position of the dynamicLegendComponent using the dynamicLegendContainerStyle property in the pointerConfig

You are supposed to assign a callback function to dynamicLegendComponent. The callback function receives 2 parameters-

1. Array of currently selected items (in case you are rendering a single line, the array will have a single item)
2. Index of the selected item.
   

Note: The legend component appears only as long as the pointer remains remains on the screen. To make the dynamic legend remain persistently on the screen, you can set the persistPointer property to true. The initialPointerIndex property can also be useful.

onFocus and strip related props

Line or Area charts can be made interactive by allowing users to press on the chart and highlight that particular data point. For example-

To achieve this the focusEnabled props must be set to true. In addition, use below props like focusedDataPointShape, focusedDataPointColor, focusedDataPointRadius to focus the pressed data point. The prop onFocus can be used to pass a function that will be called when a data point is focused.

Prop	Type	Description	Default value
focusEnabled	boolean	If set true, allows users to press on the chart and focuses the nearest data point (focus event can be then handled using the onFocus prop)	false
onFocus	Function	The callback function that handles the focus event. item and index are received as props	_
focusedDataPointIndex	number	Index of the focused data point, used to set initially focused data point and to override the focus behaviour on onFocus	_
showDataPointOnFocus	boolean	If set true, it shows the data point corresponding to the focused area of the chart	false
showStripOnFocus	boolean	If set true, it shows a vertical strip corresponding to the focused area of the chart	false
stripOverDataPoints	boolean	If set true, the vertical strip appears over the data points, else it appears beneath the data points	false
showTextOnFocus	boolean	If set true, it shows the data point text corresponding to the focused area of the chart	false
showDataPointLabelOnFocus	boolean	If set true, it shows the data point corresponding to the focused area of the chart	false
stripHeight	number	Height of the vertical strip that becomes visible on pressing the corresponding area of the chart	height of the data point
stripWidth	number	Width of the vertical strip that becomes visible on pressing the corresponding area of the chart	2
stripColor	ColorValue	Color of the vertical strip that becomes visible on pressing the corresponding area of the chart	'orange'
stripOpacity	number	Opacity of the vertical strip that becomes visible on pressing the corresponding area of the chart	(startOpacity+endOpacity)/2
stripStrokeDashArray	Array	Array of 2 numbers denoting the dashWidth and dashGap of the vertical strip	_
stripStrokeDashArray	Array	Array of 2 numbers denoting the dashWidth and dashGap of the vertical strip	_
unFocusOnPressOut	boolean	If set true, it unselects/unfocuses the focused/selected data point	true
delayBeforeUnFocus	number	Delay (in milliseconds) between the release of the press and ghe unfocusing of the data point	300
focusedDataPointShape	String	Shape of the data points when focused due to press event	item.dataPointsShape OR dataPointsShape
focusedDataPointWidth	number	Width of the data points when focused due to press event	item.dataPointsWidth OR dataPointsWidth
focusedDataPointHeight	number	Height of the data points when focused due to press event	item.dataPointsHeight OR dataPointsHeight
focusedDataPointColor	ColorValue	Color of the data points when focused due to press event	item.dataPointsColor OR dataPointsColor
focusedDataPointRadius	number	Radius of the data points when focused due to press event	item.dataPointsRadius OR dataPointsRadius
focusedCustomDataPoint	Function	Custom data point when focused due to press event	item.customDataPoint OR customDataPoint

Example of onFocus :

onFocus={(item, index) => {
    Alert.alert(item.value)
}}

Note Some props have been renamed in version 1.3.2 Here is the list of prop names changed in version 1.3.2-

Prop name prior to version 1.3.2	Prop name in and after 1.3.2
pressEnabled	focusEnabled
onPress	onFocus (onPress also exists but has diffferent functionality)
showDataPointOnPress	showDataPointOnFocus
showStripOnPress	showStripOnFocus
showTextOnPress	showTextOnFocus

---

Props for Area Chart

Prop	Type	Description	Default value
areaChart	boolean	If set true, renders area chart instead of line chart	false
areaChart1	boolean	If set true, renders area chart for 1st data set instead of line chart	areaChart
areaChart2	boolean	If set true, renders area chart for 2nd data set instead of line chart	areaChart
areaChart3	boolean	If set true, renders area chart for 3rd data set instead of line chart	areaChart
areaChart4	boolean	If set true, renders area chart for 4th data set instead of line chart	areaChart
areaChart5	boolean	If set true, renders area chart for 5th data set instead of line chart	areaChart
startFillColor	ColorValue	Start gradient color for the area chart	gray
endFillColor	ColorValue	End gradient color for the area chart	white
startOpacity	number	Start gradient opacity for the area chart	1
endOpacity	number	End gradient opacity for the area chart	1
startFillColor1	ColorValue	Start gradient color for the first dataset of the area chart	gray
endFillColor1	ColorValue	End gradient color for the first dataset of the area chart	white
startOpacity1	number	Start gradient opacity for the first dataset of the area chart	1
endOpacity1	number	End gradient opacity for the first dataset of the area chart	1
startFillColor2	ColorValue	Start gradient color for the second dataset of the area chart	gray
endFillColor2	ColorValue	End gradient color for the second dataset of the area chart	white
startOpacity2	number	Start gradient color for the second dataset of the area chart	1
endOpacity2	number	End gradient opacity for the second dataset of the area chart	1
startFillColor3	ColorValue	Start gradient color for the third dataset of the area chart	gray
endFillColor3	ColorValue	End gradient color for the third dataset of the area chart	white
startOpacity3	number	Start gradient color for the third dataset of the area chart	1
endOpacity3	number	End gradient opacity for the third dataset of the area chart	1
startFillColor4	ColorValue	Start gradient color for the fourth dataset of the area chart	gray
endFillColor4	ColorValue	End gradient color for the fourth dataset of the area chart	white
startOpacity4	number	Start gradient color for the fourth dataset of the area chart	1
endOpacity4	number	End gradient opacity for the fourth dataset of the area chart	1
startFillColor5	ColorValue	Start gradient color for the fifth dataset of the area chart	gray
endFillColor5	ColorValue	End gradient color for the fifth dataset of the area chart	white
startOpacity5	number	Start gradient color for the fifth dataset of the area chart	1
endOpacity5	number	End gradient opacity for the fifth dataset of the area chart	1
gradientDirection	string	Direction of the gradient ('horizontal' or 'vertical')	'vertical'
areaGradientComponent	Function	this prop defines the svg gradient that should be applied to the area (requires areaChart to be truthy)	null
areaGradientId	string	id of the (needed along with areaGradientComponent prop)	_
onChartAreaPress	Function	Callback function called on pressing the chart area	_
intersectionAreaConfig	IntersectionAreaConfig	Config object that defines properties for intersection area of data and data2 (1st & 2nd areas)	_

IntersectionAreaConfig

See https://stackoverflow.com/questions/78435388/react-native-area-chart

type IntersectionAreaConfig {
  fillColor: ColorValue // default: 'white'
}

Example of areaGradientComponent

Same as example of lineGradientComponent