KeyframeEffect.setKeyframes

The setKeyframes() method of the KeyframeEffect interface replaces the keyframes that make up the affected KeyframeEffect with a new set of keyframes.

Syntax

existingKeyframeEffect.setKeyframes(keyframes);

Parameters

keyframes

A keyframe object or null. If set to null, the keyframes are replaced with a sequence of empty keyframes.

There are two different ways to format keyframes:

1. An object containing key-value pairs consisting of the property to animate and an array of values to iterate over.

   element.animate({
     opacity: [ 0, 1 ],          // [ from, to ]
     color:   [ "#fff", "#000" ] // [ from, to ]
   }, 2000);
   

2. An array of objects (keyframes) consisting of properties and values to iterate over. This is the canonical format returned by the getKeyframes() method.

   element.animate([ 
     { // from
       opacity: 0,
       color: "#fff"
     }, 
     { // to
       opacity: 1,
    ​   color: "#000"
     }
   ], 2000);

   With this latter form it is also possible to specify offsets for each keyframe by providing an offset value.

   element.animate([ { opacity: 1 },
                     { opacity: 0.1, offset: 0.7 },
                     { opacity: 0 } ],
                   2000);
   

   Note: offset values, if provided, must be between 0.0 and 1.0 and arranged in ascending order.

   Furthermore, using this form it is also possible to specify easing to apply between keyframes by providing an easing value as illustrated below.

   element.animate([ { opacity: 1, easing: 'ease-out' },
                     { opacity: 0.1, easing: 'ease-in' },
                     { opacity: 0 } ],
                   2000);
   

   In this example, the specified easing only applies from the keyframe where it is specified until the next keyframe. Any easing value specified on the options argument, however, applies across a single iteration of the animation — for the entire duration.

Return value

Void.

Exceptions

Exception	Explanation
TypeError	One or more of the frames were not of the correct type of object, the keyframes were not loosely sorted by offset, or a keyframe existed with an offset of less than 0 or more than 1.

Examples

// passing an array of keyframe objects
existingKeyframeEffect.setKeyframes(
[
  { color: 'blue' },
    { color: 'green', left: '10px' }
  ]
);

// passing an object with arrays for values
existingKeyframeEffect.setKeyframes(
  {
    color: ['blue', 'green'],
    left: [ '0', '10px']
  }
);

// passing a single-member object
existingKeyframeEffect.setKeyframes(
  {
    color: 'blue'
  }
);

Specifications

Specification	Status	Comment
Web Animations The definition of 'KeyframeEffect.setKeyframes()' in that specification.	Working Draft	Editor's draft.

Browser compatibility

See also

• KeyframeEffect Interface
• Web Animations API