script-loader.js

import Ember from 'ember';
import config from 'garaje/config/environment';


// based on https://karl-sjogren.com/2015/08/05/lazy-loading-extra-scripts-in-ember/

const LOADING = {};

function scriptLoader(id, src, parent = 'head') {
  let promise;

  if (LOADING[id]) {
    promise = LOADING[id];
  } else {
    promise = LOADING[id] = new Ember.RSVP.Promise(function(resolve, reject) {
      if(!!document.getElementById(id)) {
        delete LOADING[id];

        return resolve(true);
      }

      var script = document.createElement('script');
      script.async = true;
      script.id = id;
      script.src = src;
      script.type = 'text/javascript';
      script.addEventListener('load', function() {
        resolve(true);
      });
      script.addEventListener('error', function() {
        reject(`Failed to load ${id} (${src})`);
      });
      document.getElementsByTagName(parent)[0].appendChild(script);
    }, `Loading external script resource ${id} (${src})`);
  }
  return promise;
}

export default scriptLoader;

export function loadGoogleMaps() {
  if (config.environment === 'test') {
    return Ember.RSVP.resolve();
  }

  let id = 'envoygmapsjs';
  let src = 'https://maps.googleapis.com/maps/api/js?v=3.exp&sensor=true&libraries=places&key=' + config.googleApiKey;

  return scriptLoader(id, src);
}

export function loadHeadway() {
  if (config.environment === 'test') {
    return Ember.RSVP.resolve();
  }

  let id = 'envoyheadwayapp';
  let src = 'https://cdn.headwayapp.co/widget.js';

  return scriptLoader(id, src);
}


export function loadSrcDoc() {
  let isIE = window.navigator.userAgent.match(/MSIE|Trident/);

  if (!isIE) {
    return Ember.RSVP.resolve(false);
  }

  let id = 'envoysrcdocspolyfill';
  let src = 'https://dashboard.envoy.com/shims/srcdoc-polyfill.min.js';

  return scriptLoader(id, src, 'body');
}

export function loadLiveChat() {
  if (window.matchMedia('only screen and (min-width: 641px)').matches) {
    window.__lc = {};
    window.__lc.license = 5914591;

    let src = 'https://cdn.livechatinc.com/tracking.js';

    return scriptLoader('envoylc', src, 'body');
  } else {
    return Ember.RSVP.resolve(false);
  }

}