Add support for React refs on Box #52
Description
This is a great library, however it is missing a way to attach a ref to Box's underlying DOM node. This is useful for integrations with other third party libraries.
Specifically we want to be able to integrate with react-beautiful-dnd, which requires an exposed ref on the draggable items.
Would you be open to a PR that introduces an elementRef prop to the Box component?
Example usage:
render() {
return (
<Box elementRef={...}>
{this.props.children}
</Box>
);
}