navody-digital-frontend/govuk/common.js

Navody.Digital Frontend contains the code you need to start building a user interface for navody.digital

(function (global, factory) {
	typeof exports === 'object' && typeof module !== 'undefined' ? factory(exports) :
	typeof define === 'function' && define.amd ? define('navodyDigitalFrontend', ['exports'], factory) :
	(factory((global.navodyDigitalFrontend = {})));
}(this, (function (exports) { 'use strict';

/**
 * TODO: Ideally this would be a NodeList.prototype.forEach polyfill
 * This seems to fail in IE8, requires more investigation.
 * See: https://github.com/imagitama/nodelist-foreach-polyfill
 */
function nodeListForEach (nodes, callback) {
  if (window.NodeList.prototype.forEach) {
    return nodes.forEach(callback)
  }
  for (var i = 0; i < nodes.length; i++) {
    callback.call(window, nodes[i], i, nodes);
  }
}

// Used to generate a unique string, allows multiple instances of the component without
// Them conflicting with each other.
// https://stackoverflow.com/a/8809472
function generateUniqueID () {
  var d = new Date().getTime();
  if (typeof window.performance !== 'undefined' && typeof window.performance.now === 'function') {
    d += window.performance.now(); // use high-precision timer if available
  }
  return 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'.replace(/[xy]/g, function (c) {
    var r = (d + Math.random() * 16) % 16 | 0;
    d = Math.floor(d / 16);
    return (c === 'x' ? r : (r & 0x3 | 0x8)).toString(16)
  })
}

function on (elSelector, eventName, selector, fn) {
  var element = document.querySelector(elSelector);

  element.addEventListener(eventName, function (event) {
    var possibleTargets = element.querySelectorAll(selector);
    var target = event.target;

    for (var i = 0, l = possibleTargets.length; i < l; i++) {
      var el = target;
      var p = possibleTargets[i];

      while (el && el !== element) {
        if (el === p) {
          return fn.call(p, event)
        }

        el = el.parentNode;
      }
    }
  });
}

exports.nodeListForEach = nodeListForEach;
exports.generateUniqueID = generateUniqueID;
exports.on = on;

})));