SVGTransformList

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since ⁨July 2015⁩.

The SVGTransformList interface defines a list of SVGTransform objects.

An SVGTransformList object can be designated as read only, which means that attempts to modify the object will result in an exception being thrown.

An SVGTransformList is indexable and can be accessed like an array.

Instance properties

numberOfItems: The number of items in the list.
length: The number of items in the list.

Instance methods

clear(): Clears all existing current items from the list, with the result being an empty list.
initialize(): Clears all existing current items from the list and re-initializes the list to hold the single item specified by the parameter. If the inserted item is already in a list, it is removed from its previous list before it is inserted into this list. The inserted item is the item itself and not a copy. The return value is the item inserted into the list.
getItem(): Returns the specified item from the list. The returned item is the item itself and not a copy. Any changes made to the item are immediately reflected in the list. The first item is number 0.
insertItemBefore(): Inserts a new item into the list at the specified position. The first item is number 0. If newItem is already in a list, it is removed from its previous list before it is inserted into this list. The inserted item is the item itself and not a copy. If the item is already in this list, note that the index of the item to insert before is before the removal of the item. If the index is equal to 0, then the new item is inserted at the front of the list. If the index is greater than or equal to numberOfItems, then the new item is appended to the end of the list.
replaceItem(): Replaces an existing item in the list with a new item. If newItem is already in a list, it is removed from its previous list before it is inserted into this list. The inserted item is the item itself and not a copy. If the item is already in this list, note that the index of the item to replace is before the removal of the item.
removeItem(): Removes an existing item from the list.
appendItem(): Inserts a new item at the end of the list. If newItem is already in a list it is removed from its previous list before it is inserted into this list. The inserted item is the item itself and not a copy.
createSVGTransformFromMatrix(): Creates an SVGTransform object which is initialized to transform of type SVG_TRANSFORM_MATRIX and whose values are the given matrix. The values from the parameter matrix are copied, the matrix parameter is not adopted as SVGTransform::matrix.
consolidate(): Consolidates the list of separate SVGTransform objects by multiplying the equivalent transformation matrices together to result in a list consisting of a single SVGTransform object of type SVG_TRANSFORM_MATRIX. The consolidation operation creates new SVGTransform object as the first and only item in the list. The returned item is the item itself and not a copy. Any changes made to the item are immediately reflected in the list.

In this example we create a function that will apply three different transformations to the SVG element that has been clicked on. In order to do this we create a separate SVGTransform object for each transformation — such as translate, rotate, and scale. We apply multiple transformation by appending the transform object to the SVGTransformList associated with an SVG element.

html

<svg
  id="my-svg"
  viewBox="0 0 300 280"
  xmlns="http://www.w3.org/2000/svg"
  version="1.1">
  <desc>
    Example showing how to transform svg elements that using SVGTransform
    objects
  </desc>
  <polygon
    fill="orange"
    stroke="black"
    stroke-width="5"
    points="100,225 100,115 130,115 70,15 70,15 10,115 40,115 40,225" />
  <rect
    x="200"
    y="100"
    width="100"
    height="100"
    fill="yellow"
    stroke="black"
    stroke-width="5" />
  <text x="40" y="250" font-family="Verdana" font-size="16" fill="green">
    Click on a shape to transform it
  </text>
</svg>

function transformMe(evt) {
  // svg root element to access the createSVGTransform() function
  const svgRoot = evt.target.parentNode;
  // SVGTransformList of the element that has been clicked on
  const tfmList = evt.target.transform.baseVal;

  // Create a separate transform object for each transform
  const translate = svgRoot.createSVGTransform();
  translate.setTranslate(50, 5);
  const rotate = svgRoot.createSVGTransform();
  rotate.setRotate(10, 0, 0);
  const scale = svgRoot.createSVGTransform();
  scale.setScale(0.8, 0.8);

  // apply the transformations by appending the SVGTransform objects to the SVGTransformList associated with the element
  tfmList.appendItem(translate);
  tfmList.appendItem(rotate);
  tfmList.appendItem(scale);
}

document.querySelector("polygon").addEventListener("click", transformMe);
document.querySelector("rect").addEventListener("click", transformMe);