in tools/preview/ui/TreeView.js [5:14]
renderLevel(fields, depth) {
return (fields || []).map(field => {
return (
<div key={field.id} style={{ paddingLeft: `${20 * depth}px` }}>
{field.id}
<button type="button" onClick={e => this.props.onEditFieldClick(field)}>Edit</button>
{this.renderLevel(field.fields, depth + 1)}
</div>
);
});