ReactJS change background image dynamically?

Question

I was trying to change background image style dynamically for the following div:

Here is my component for changing it,

render: function() {
  var divImage = {
    backgroundImage : "url(" + this.state.song.imgSrc + "),url(" + this.state.nextImgSrc + ");" 
  };

  return (
    <li>
      <div ref="image-pane" className="player" style={divImage}></div>
    </li>
  )
}

Thanks for the help

Solution 1

You haven't specified when would you like to change backgroundImage, so I've created version which changes it with onClick:

React.createClass({
    getInitialState: function () {
        nextImg: false,
    },
    handleClick: function () {
        this.setState({ nextImg: !this.state.nextImg })
    },
    render: function() {
        var imgUrl = this.state.nextImg ? this.state.nextImgSrc : this.state.song.imgSrc;
        var divStyle = {
            backgroundImage: 'url(' + imgUrl + ')'
        }

        return (
            <li>
                <div ref="image-pane" style={divStyle} onClick={this.handleClick} className="player"></div>
            </li>
        )
    }
});

Notice that backgroundImage: 'url(' + imgUrl + ')' no longer must have trailing semicolon, in fact the trailing semicolon will cause React to raise and error.

Solution 2

This is caused by the trailing semicolon in your style. See react issues #2862.

Comments

[Harkirat Saluja]

why does semicolon cause an error in this? @daniula

[daniula]

@HarkiratSaluja This was an issue with React itself. See github.com/facebook/react/issues/2862 pointed out by FakeRainBrigand