domtastic/src/util.js

Small, fast, and modular DOM and event library for modern browsers.

/*
 * @module Util
 */

/*
 * Reference to the window object
 * @private
 */

export const win = typeof window !== 'undefined' ? window : {};

/**
 * Convert `NodeList` to `Array`.
 *
 * @param {NodeList|Array} collection
 * @return {Array}
 * @private
 */

export const toArray = collection => {
  const length = collection.length;
  const result = new Array(length);
  for(let i = 0; i < length; i++) {
    result[i] = collection[i];
  }
  return result;
};

/**
 * Faster alternative to [].forEach method
 *
 * @param {Node|NodeList|Array} collection
 * @param {Function} callback
 * @return {Node|NodeList|Array}
 * @private
 */

export const each = (collection, callback, thisArg) => {
  const length = collection.length;
  if(length !== undefined && collection.nodeType === undefined) {
    for(let i = 0; i < length; i++) {
      callback.call(thisArg, collection[i], i, collection);
    }
  } else {
    callback.call(thisArg, collection, 0, collection);
  }
  return collection;
};

/**
 * Assign enumerable properties from source object(s) to target object
 *
 * @method extend
 * @param {Object} target Object to extend
 * @param {Object} [source] Object to extend from
 * @return {Object} Extended object
 * @example
 *     $.extend({a: 1}, {b: 2}); // {a: 1, b: 2}
 * @example
 *     $.extend({a: 1}, {b: 2}, {a: 3}); // {a: 3, b: 2}
 */

export const extend = (target, ...sources) => {
  sources.forEach(src => {
    for(let prop in src) {
      target[prop] = src[prop];
    }
  });
  return target;
};

/**
 * Return the collection without duplicates
 *
 * @param collection Collection to remove duplicates from
 * @return {Node|NodeList|Array}
 * @private
 */

export const uniq = collection => collection.filter((item, index) => collection.indexOf(item) === index);