Add ability to load a map file manually

src/index.js

@@ -12,6 +12,7 @@ const mapPlaceholder = document.querySelector('.map-placeholder'),
   // fileName = localStorage.getItem('map') || (env === 'test' ? 'test_map' : 'map1'),
   fileName = localStorage.getItem('map') || 'map1',
   map = `assets/images/${fileName}.svg`,
+  fileInputEl = document.querySelector('input[type="file"]'),
 
   toggleContentVis = (function () {
     document.querySelectorAll('#content div').forEach(div => {
@@ -64,6 +65,7 @@ function clearMoveEndedIndicators(records) {
 }
 
 function load() {
+  URL.revokeObjectURL(this.data);
   const svg = this.contentDocument.querySelector('svg'),
     startLocs = svg.querySelector('.start-locations');
 
@@ -156,3 +158,12 @@ document.querySelector('#download-save').addEventListener('click', e => {
   element.click();
   // document.body.removeChild(element);
 });
+
+document.querySelector('#upload-save').addEventListener('click', () => {
+  fileInputEl.click();
+});
+
+document.querySelector('input[type="file"]').addEventListener('change', e => {
+  const [file] =  fileInputEl.files;
+  document.querySelector('object').data = URL.createObjectURL(file);
+});