@bblocks/compose/compose.js

This library is a handy helper if you work with objects, inheritance and composition, like to code efficiently and need to support all modern browser and IE11 without transpiling.

/** @module bb/compose */

/** 
 * Compose two or more objects
 * @param {...object} Objects to compose.  target, source1, source2, ...
 * @return {object} Target object.
*/
function mix() {
	var args = arguments,
		source = args[0];
	
	if (source == undefined) { return; }
	if (args.length <= 1) { return source; }

	for (var i = 1; i < args.length; i++) {
		var obj = args[i];
		if (typeof obj != 'object') {
			console.warn('Invalid parameter type "' + (typeof obj) + '" for the argument #' + i);
			continue;
		}
		Object.defineProperties(source, Object.getOwnPropertyDescriptors(obj));
	}
	return source;
}

/** 
 * Inherit and compose
 * @param {...object} Prototype and optional additional sources for composition
 * @return {object} New object created from the prototype and results of composition
*/
function clone() {
	var args = arguments;
	if (args[0] == undefined) { args[0] = Object.prototype; }
	args[0] = Object.create(args[0], Object.getOwnPropertyDescriptors(args[0]));
	if (args.length == 1) { return args[0]; }
	return mix.apply(this, args);
}

// Object.getOwnPropertyDescriptors polyfill for IE11
if (!Object.hasOwnProperty('getOwnPropertyDescriptors')) {
	var supportsSymbol = Object.hasOwnProperty('getOwnPropertySymbols');
	Object.defineProperty(
		Object,
		'getOwnPropertyDescriptors',
		{
			configurable: true,
			writable: true,
			value: function getOwnPropertyDescriptors(object) {
				var keys = Object.getOwnPropertyNames(object);
				if (supportsSymbol) {
					keys = keys.concat(Object.getOwnPropertySymbols(object));
				}

				return keys.reduce(function (descriptors, key) {
					return Object.defineProperty(
						descriptors,
						key,
						{
							configurable: true,
							enumerable: true,
							writable: true,
							value: Object.getOwnPropertyDescriptor(object, key)
						}
					);
				}, {});
			}
		}
	);
}

// Object assign polyfill for IE11
if (!Object.assign) {
	function assign(target, firstSource) {
		if (target === undefined || target === null) {
			throw new TypeError('Cannot convert first argument to object');
		}

		var to = Object(target);
		for (var i = 1; i < arguments.length; i++) {
			var nextSource = arguments[i];
			if (nextSource === undefined || nextSource === null) {
				continue;
			}

			var keysArray = Object.keys(Object(nextSource));
			for (var nextIndex = 0, len = keysArray.length; nextIndex < len; nextIndex++) {
				var nextKey = keysArray[nextIndex];
				var desc = Object.getOwnPropertyDescriptor(nextSource, nextKey);
				if (desc !== undefined && desc.enumerable) {
					to[nextKey] = nextSource[nextKey];
				}
			}
		}
		return to;
	}
	Object.defineProperty(Object, 'assign', {
		enumerable: false,
		configurable: true,
		writable: true,
		value: assign
	});
}

/**
 * Building block with handy methods
 */
var block = {
	mix: function() {
		Array.prototype.unshift.call(arguments, this);
		mix.apply(this, arguments);
		return this;
	},
	clone: function() {
		Array.prototype.unshift.call(arguments, this);
		return clone.apply(this, arguments);
	},
	define: function() {
		if (!arguments.length) {return this;}
		for (var i=0; i<arguments.length; i++) {
			Object.defineProperties(this, arguments[i]);
		}
		return this;
	}
}
var Block = function() {
	Array.prototype.unshift.call(arguments, this);
	mix.apply(this, arguments);
};
Block.prototype = block;
export {mix, clone, block, Block};