Vue3属性绑定方法解析

const mountElement = (vnode, container, anchor, parentComponent, parentSuspense, isSVG, slotScopeIds, optimized) => {
  let el;
  // ...
  const { type, props, shapeFlag, transition, patchFlag, dirs } = vnode;
  {
      el = vnode.el = hostCreateElement(vnode.type, isSVG, props && props.is, props);
      // ...
      // props
      if (props) {
          for (const key in props) {
              if (key !== 'value' && !isReservedProp(key)) {
                  hostPatchProp(el, key, null, props[key], isSVG, vnode.children, parentComponent, parentSuspense, unmountChildren);
              }
          }
          // ...
      }
      // ...
  }
  // ...
  hostInsert(el, container, anchor);
  // ...
};

const patchProp = (el, key, prevValue, nextValue, isSVG = false, prevChildren, parentComponent, parentSuspense, unmountChildren) => {
      if (key === 'class') {
          patchClass(el, nextValue, isSVG);
      }
      else if (key === 'style') {
          patchStyle(el, prevValue, nextValue);
      }
      else if (isOn(key)) {
          // ignore v-model listeners
          if (!isModelListener(key)) {
              patchEvent(el, key, prevValue, nextValue, parentComponent);
          }
      }
      else if (key[0] === '.'
          ? ((key = key.slice(1)), true)
          : key[0] === '^'
              ? ((key = key.slice(1)), false)
              : shouldSetAsProp(el, key, nextValue, isSVG)) {
          patchDOMProp(el, key, nextValue, prevChildren, parentComponent, parentSuspense, unmountChildren);
      }
      else {
          if (key === 'true-value') {
              el._trueValue = nextValue;
          }
          else if (key === 'false-value') {
              el._falseValue = nextValue;
          }
          patchAttr(el, key, nextValue, isSVG);
      }
  };

function shouldSetAsProp(el, key, value, isSVG) {
      if (isSVG) {
          // most keys must be set as attribute on svg elements to work
          // ...except innerHTML & textContent
          if (key === 'innerHTML' || key === 'textContent') {
              return true;
          }
          // or native onclick with function values
          if (key in el && nativeOnRE.test(key) && isFunction(value)) {
              return true;
          }
          return false;
      }
      // these are enumerated attrs, however their corresponding DOM properties
      // are actually booleans - this leads to setting it with a string "false"
      // value leading it to be coerced to `true`, so we need to always treat
      // them as attributes.
      // Note that `contentEditable` doesn't have this problem: its DOM
      // property is also enumerated string values.
      if (key === 'spellcheck' || key === 'draggable' || key === 'translate') {
          return false;
      }
      // #1787, #2840 form property on form elements is readonly and must be set as
      // attribute.
      if (key === 'form') {
          return false;
      }
      // #1526 <input list> must be set as attribute
      if (key === 'list' && el.tagName === 'INPUT') {
          return false;
      }
      // #2766 <textarea type> must be set as attribute
      if (key === 'type' && el.tagName === 'TEXTAREA') {
          return false;
      }
      // native onclick with string value, must be set as attribute
      if (nativeOnRE.test(key) && isString(value)) {
          return false;
      }
      return key in el;
  }

return key in el;