Function updateAttrs

static/vuejs/vue.runtime.esm.js:5239–5273

(oldVnode, vnode)

/*  */

function updateAttrs (oldVnode, vnode) {
  if (!oldVnode.data.attrs && !vnode.data.attrs) {
    return
  }
  var key, cur, old;
  var elm = vnode.elm;
  var oldAttrs = oldVnode.data.attrs || {};
  var attrs = vnode.data.attrs || {};
  // clone observed objects, as the user probably wants to mutate it
  if (attrs.__ob__) {
    attrs = vnode.data.attrs = extend({}, attrs);
  }

  for (key in attrs) {
    cur = attrs[key];
    old = oldAttrs[key];
    if (old !== cur) {
      setAttr(elm, key, cur);
    }
  }
  // #4391: in IE9, setting type can reset value for input[type=radio]
  /* istanbul ignore if */
  if (isIE9 && attrs.value !== oldAttrs.value) {
    setAttr(elm, 'value', attrs.value);
  }
  for (key in oldAttrs) {
    if (attrs[key] == null) {
      if (isXlink(key)) {
        elm.removeAttributeNS(xlinkNS, getXlinkProp(key));
      } else if (!isEnumeratedAttr(key)) {
        elm.removeAttribute(key);
      }
    }
  }
}

function setAttr (el, key, value) {
  if (isBooleanAttr(key)) {