map-object-to-props.js

import { h } from 'preact';

function lastChild(arr) {
	return arr && arr.length ? arr[arr.length - 1] : undefined;
}

function get(obj, key, def, p) {
	p = 0;
	key = key.split ? key.split('.') : key;
	while (obj && p<key.length) obj = obj[key[p++]];
	return obj===undefined ? def : obj;
}

function withObject(getObj) {
	if (getObj && typeof getObj === 'object') {
		let obj = getObj;
		getObj = () => obj;
	}
	function mapper(obj, mapToProps) {
		let key, props = {};
		if (!mapToProps) { return props; }

		if (typeof mapToProps === 'string') {
			let paths = mapToProps.split(',');
			for (key in paths) {
				let path = paths[key];
				let prop = lastChild(path.split('.'));
				props[prop] = get(obj, path);
			}
			return props;
	        }

		if (typeof mapToProps === 'object') {
			for (key in mapToProps) {
				props[key] = mapper(obj, mapToProps[key]);
		        }
			return props;
		}
		if (typeof mapToProps === 'function') {
			return mapToProps(obj);
    }
	}

	return (mapToProps) => (Child) => (props, state, context) => (
		h(Child, Object.assign({}, mapper(getObj(props, context), mapToProps), props))
	);
}