// Component.js
class MyComponent extends React.Component {
    render() {
        <div> {this.props.myData} </div>
    }
}
initComponent(data) {
    ReactDOM.render(
        <MyComponent myData={data} />
    )
}

// ComponentPage.scala.html
...
<script>
  $(() => initComponent(@scala.serverVariable.getData(currentUser))
</script>