javascript - ReactJS, CSS and SVG animations, and re-rendering - Stack Overflow

The issue can be seen in action here:

On first load, you'll see the blue circle going around and the red box fading out and in.
The circle is animated via svg tag and the box via css animations.
If you click anywhere on the canvas, the code triggers a re-render, which can be verified by opening the console.

My expectation would be for both animations to reset on click, however that does not happen.
I have a hunch that this has something to do with caching and react's shadow DOM.

Why's this happening? How to fix it?

The code is the following:

#nonSvgBox {
  animation-duration: 1s;
  animation-name: fade;
  width: 100px;
  height: 100px;
  background-color: red;
}

@keyframes fade {
  from {
    opacity: 1;
  }
  to {
    opacity: 0;
  }
}

class Component extends React.Component {
  onClick() {
    this.setState({a: 1});
  }

  render() {
    console.log('rendering');
    return (
      <div onClick={() => this.onClick()}>
        <svg>
          <path 
            stroke="blue"
            strokeWidth="10"
            fill="transparent"
            d="M50 10 a 40 40 0 0 1 0 80 a 40 40 0 0 1 0 -80"
            strokeDasharray="251.2,251.2">
            <animate
              attributeType="css"
              attributeName="stroke-dasharray"
              from="0" to="251.2" dur="1s" />
          </path>
        </svg>
        <div id="nonSvgBox"></div>
      </div>
    );
  }
}

ReactDOM.render(<Component />, document.getElementById('app'));

Thank you.

The issue can be seen in action here:
https://codepen.io/fsabe/pen/opEVNR?editors=0110

On first load, you'll see the blue circle going around and the red box fading out and in.
The circle is animated via svg tag and the box via css animations.
If you click anywhere on the canvas, the code triggers a re-render, which can be verified by opening the console.

My expectation would be for both animations to reset on click, however that does not happen.
I have a hunch that this has something to do with caching and react's shadow DOM.

Why's this happening? How to fix it?

The code is the following:

#nonSvgBox {
  animation-duration: 1s;
  animation-name: fade;
  width: 100px;
  height: 100px;
  background-color: red;
}

@keyframes fade {
  from {
    opacity: 1;
  }
  to {
    opacity: 0;
  }
}

class Component extends React.Component {
  onClick() {
    this.setState({a: 1});
  }

  render() {
    console.log('rendering');
    return (
      <div onClick={() => this.onClick()}>
        <svg>
          <path 
            stroke="blue"
            strokeWidth="10"
            fill="transparent"
            d="M50 10 a 40 40 0 0 1 0 80 a 40 40 0 0 1 0 -80"
            strokeDasharray="251.2,251.2">
            <animate
              attributeType="css"
              attributeName="stroke-dasharray"
              from="0" to="251.2" dur="1s" />
          </path>
        </svg>
        <div id="nonSvgBox"></div>
      </div>
    );
  }
}

ReactDOM.render(<Component />, document.getElementById('app'));

Thank you.

• javascript
• css
• reactjs
• svg

Share Improve this question Follow edited Jan 10, 2018 at 1:51 fs_ asked Jan 10, 2018 at 1:39 fs_fs_ 19622 silver badges77 bronze badges

Add a ment  | 

1 Answer 1

Sorted by: Reset to default 6

React is reusing the elements, therefore the animations won't replay b/c they've already played for the current elements.

I think it's easier to resort to dom operations in this situation, versus some setState trickery.

https://codepen.io/guanzo/pen/vpdPzX?editors=0110

Store the refs to the 2 elements, then trigger the animations with JS.

class Component extends React.Component {
  onClick() {
    this.svgAnimate.beginElement()//triggers animation
    this.square.style.animation = 'none';//override css animation
    this.square.offsetHeight; /* trigger reflow */
    this.square.style.animation = null; //fallback to css animation
  }

    render() {
    console.log('rendering');
        return (
            <div onClick={() => this.onClick()}>
                <svg>
                    <path 
                        stroke="blue"
            strokeWidth="10"
                        fill="transparent"
                        d="M50 10 a 40 40 0 0 1 0 80 a 40 40 0 0 1 0 -80"
            strokeDasharray="251.2,251.2">
              <animate
                ref={(svgAnimate) => { this.svgAnimate = svgAnimate; }} 
                attributeType="css"
                attributeName="stroke-dasharray"
                from="0" to="251.2" dur="1s" />
                </path>
              </svg>
        <div id="nonSvgBox"
          ref={(square) => { this.square = square; }} 
          ></div>
            </div>
        );
    }
}

ReactDOM.render(<Component />, document.getElementById('app'));