constantLines[]

Defines an array of the value axis constant lines.

Type:

Array<Object>

Cannot be used in themes.

A constant line is a straight line that can be used to display, for example, an asymptote of a graph. To display constant lines on a chart, assign an array of objects specifying the properties of each constant line to the constantLines field. It is necessary to set the value property within these objects. The other properties can be set if required.

You can customize the appearance of all the value axis constant lines at once. For this purpose, use the valueAxis.constantLineStyle configuration object. Note that the properties that are set within the valueAxis.constantLine object override the corresponding properties that are set within the valueAxis.constantLineStyle object.

color

Specifies a color for a constant line.

Type:

String

Default Value: '#000000'

This property supports the following colors:

dashStyle

Specifies a dash style for a constant line.

Type:

String

Default Value: 'solid'
Accepted Values: 'dash' | 'dot' | 'longDash' | 'solid'

The following dash styles are available:

  • solid
    The border is a solid, continuous line.

  • longDash
    The border is displayed using long dashes.

  • dash
    The border is displayed using dashes.

  • dot
    The border is displayed using dots.

  • Any combination of 'longDash', 'dash' and 'dot'
    The border is displayed by repeating the specified combination. For instance, 'dashdotdash'.

displayBehindSeries

Specifies whether to display the constant line behind or in front of the series.

Type:

Boolean

Default Value: false

DevExtreme Chart - Display constant lines behind series

extendAxis

Specifies whether to extend the axis to display the constant line.

Type:

Boolean

Default Value: false

The axis's length is calculated based on the data range. A constant line outside the data range is not displayed. Set this property to true to extend the axis and display the constant line.

label

An object defining constant line label properties.

Type:

Object

A constant line label shows information on the constant line. You can configure label appearance using the label object. Within this object, you can set font properties, a position and text using corresponding fields. In addition, you can specify the horizontal and vertical alignments for the label.

You can set the label properties for all the value axis constant lines together. For this purpose, use the valueAxis.constantLineStyle.label object. Note that the properties that are set within the valueAxis.constantLine.label object override the corresponding properties that are set within the valueAxis.constantLineStyle.label object.

value

Specifies a value to be displayed by a constant line.

Type:

Number

|

Date

|

String

Default Value: undefined

width

Specifies a constant line width in pixels.

Type:

Number

Default Value: 1