The SVGMarkerElement interface provides access to the properties of <marker> elements, as well as methods to manipulate them. The <marker> element defines the graphics used for drawing marks on a shape.

The following properties and methods all return, or act on the attributes of the <marker> element represented by SVGMarkerElement.

Instance properties

This interface also inherits properties from its parent, SVGElement.

SVGMarkerElement.markerUnits Read only

Returns an SVGAnimatedEnumeration object, with one of the following values:

0

SVG_MARKERUNITS_UNKNOWN which means that the markerUnits attribute has a value other than the two predefined keywords.

1

SVG_MARKERUNITS_USERSPACEONUSE which means that the markerUnits attribute has the keyword value userSpaceOnUse.

2

SVG_MARKERUNITS_STROKEWIDTH which means that the markerUnits attribute has the keyword value strokeWidth.

SVGMarkerElement.markerWidth Read only

Returns an SVGAnimatedLength object containing the width of the <marker> viewport.

SVGMarkerElement.markerHeight Read only

Returns an SVGAnimatedLength object containing the height of the <marker> viewport.

SVGMarkerElement.orientType Read only

Returns an SVGAnimatedEnumeration object, with one of the following values:

0

SVG_MARKER_ORIENT_UNKNOWN which means that the orient attribute has a value other than the two predefined keywords.

1

SVG_MARKERUNITS_ORIENT_AUTO which means that the orient attribute has the keyword value auto.

2

SVG_MARKERUNITS_ORIENT_ANGLE which means that the orient attribute has an <angle> or <number> value indicating the angle.

SVGMarkerElement.orient

A string defining how the marker is rotated when it is placed at its position on the shape. It reflects the orient attribute of the <marker> element.

SVGMarkerElement.orientAngle Read only

Returns an SVGAnimatedAngle object containing the angle of the orient attribute.

SVGMarkerElement.refX Read only

Returns an SVGAnimatedLength object containing the value of the refX attribute of the <marker>.

SVGMarkerElement.refY Read only

Returns an SVGAnimatedLength object containing the value of the refY attribute of the <marker>.

SVGMarkerElement.viewBox Read only

Returns an SVGAnimatedRect object containing an SVGRect which contains the values set by the viewBox attribute on the <marker>.

SVGMarkerElement.preserveAspectRatio Read only

Returns an SVGPreserveAspectRatio object which contains the values set by the preserveAspectRatio attribute on the <marker> viewport.

Instance methods

This interface also inherits methods from its parent, SVGElement.

SVGMarkerElement.setOrientToAuto()

Sets the value of the orient attribute to auto.

SVGMarkerElement.setOrientToAngle()

Sets the value of the orient attribute to a specific angle value.

Examples

The following SVG will be referenced in the examples.

<svg id="svg" viewBox="0 0 100 100" xmlns="http://www.w3.org/2000/svg">
  <defs>
    <marker
      id="arrow"
      viewBox="0 0 10 10"
      refX="5"
      refY="5"
      markerWidth="6"
      markerHeight="6"
      orient="90">
      <path d="M 0 0 L 10 5 L 0 10 z" />
    </marker>
  </defs>
</svg>

Finding the Width of the Marker

The markerWidth property returns an SVGAnimatedLength which contains an SVGLength with the value of the markerWidth attribute.

let marker = document.getElementById("arrow");
console.log(marker.markerWidth.baseVal.value); // 6

Updating the Orientation Angle

In the following example the value of the orient attribute is updated using setOrientToAngle() using an SVGAngle created using SVGSVGElement.createSVGAngle().

let svg = document.getElementById("svg");
let marker = document.getElementById("arrow");
console.log(marker.orientAngle.baseVal.value); // value in SVG above - 90
let angle = svg.createSVGAngle();
angle.value = "110";
marker.setOrientToAngle(angle);
console.log(marker.orientAngle.baseVal.value); // new value - 110

Specifications

Browser compatibility