react-templates/test/data/test.rt

<div>
    <div style= "position: relative; textAlign: center;
            top: {this.props.config.previewTop};
            height: {this.props.config.previewHeight}">

        <div style="margin: auto; height: 100%; width: {this.props.config.previewWidth || '100%'}">
            <iframe id="preview" src="http://localhost/sites/412?ds=true" style="width: 100%; height: 100%; border: 0"/>
        </div>
    </div>

    <div>editor
        <div rt-if="!this.props.editorState.previewMode">left bar</div>
    </div>
</div>