@gleaner/tracker/src/utils.js

A JavaScript tracking library with ecommerce support

// DOM Events IE8+ Support
const on = function (el, type, callback) {
	if (el.addEventListener) {
		el.addEventListener(type, callback);
	} else {
		el.attachEvent('on' + type, function() {
			callback.call(el);
		});
	}
}

const off = function (el, type, callback) {
	if (el.removeEventListener) {
		el.removeEventListener(type, callback);
	} else {
		el.detachEvent('on' + type, callback);
	}
}

/*
	'Unwraps' array to object by key. Similar to _.keyBy
	@param {Array}
	@param {String}
	@returns {Object}
*/
const keyBy = function(arr, key) {
	let result = {};
	for (let i in arr) {
		let item = arr[i];
		result[item[key]] = item;
	}
	return result;
}

/*
	@param {Object}
	@param {String}
	@returns {Object}
*/
const mapValues = function(obj, prop) {
	let result = {};

	for (let key in obj) {
		result[key] = obj[key][prop];
	}

	// Object.keys(obj).map((key) => {
	// 	result[key] = obj[key][prop];
	// });
	
	return result;
}

/*
	@returns {Boolean} flag for localStorage support
*/
function hasLocalStorage() {
	const test = '__gleaner-test__'; // random string would be better
	try {
    localStorage.setItem(test, test);
    localStorage.removeItem(test);
    return true;
	} catch(e) {
	  return false;
	}
}

/*
	Creates function for capturing track commands in a queue
	@param {Object} context e.g. window
	@returns {Function}
*/
function createInstance(ctx = {}) {
	let instance = ctx[name] = ctx[name] || function() {
		ctx[name].queue.push(arguments); // log all calls in a queue
	}
	instance.queue = instance.queue || []; // queue alredy empty before calling the function...
	return instance;
}

export {
	on,
	off,
	keyBy,
	mapValues,
	hasLocalStorage,
	createInstance,
}