/*更新VNode的class*/
function updateClass (oldVnode: any, vnode: any) {
const el = vnode.elm
const data: VNodeData = vnode.data
const oldData: VNodeData = oldVnode.data
if (
isUndef(data.staticClass) &&
isUndef(data.class) && (
isUndef(oldData) || (
isUndef(oldData.staticClass) &&
isUndef(oldData.class)
)
)
) {
return
}
let cls = genClassForVnode(vnode)
// handle transition classes
const transitionClass = el._transitionClasses
if (isDef(transitionClass)) {
cls = concat(cls, stringifyClass(transitionClass))
}
// set the class
if (cls !== el._prevClass) {
el.setAttribute('class', cls)
el._prevClass = cls
}
}
function updateClass(oldVnode, vnode) {
const el = vnode.elm
const data = vnode.data
const oldData = oldVnode.data
if (
!data.staticClass &&
!data.class &&
(!oldData || (!oldData.staticClass && !oldData.class))
) {
return
}
let cls = genClassForVnode(vnode)
// handle transition classes
const transitionClass = el._transitionClasses
if (transitionClass) {
cls = concat(cls, stringifyClass(transitionClass))
}
// set the class
if (cls !== el._prevClass) {
el.setAttribute('class', cls)
el._prevClass = cls
}
}