下載檔案函式

download (src, fileName) {
  let $a = document.createElement('a');
  $a.setAttribute('href', src);
  $a.setAttribute('download', fileName);
  let fileLink = document.createElement('span');
  fileLink.setAttribute('style', 'cursor: pointer; -webkit-tap-highlight-color: transparent');
  $a.appendChild
 
(fileLink);
  let body = document.getElementsByTagName('body')[0];
  body.appendChild($a);
  fileLink.click();
  body.removeChild($a);
},

常用輔助類

addClass: function (elem, cls) {
  if (!this.hasClass(elem, cls)) {
    elem.className = elem.className === '' ? cls : elem.className + ' ' + cls;
  }
},
removeClass
 
: function (elem, cls) {
  if (this.hasClass(elem, cls)) {
    let newClass = ' ' + elem.className.replace(/[\t\r\n]/g, '') + ' ';
    while (newClass.indexOf(' ' + cls + ' ') >= 0) {
      newClass = newClass.replace(' ' + cls + ' ', ' ');
    }
    elem.className = newClass.replace(/^\s+|\s+$/g, '');
 
  }
},