Open lefex opened 4 years ago
Vue 是一个对象,它包含了一个方法 crateApp。我们先分析下下面这段代码:
Vue.createApp(Welcome).mount('#app');
把代码拆分一下:
const app = Vue.createApp(Welcome);
app.mount('#app')
看一下 createApp 这个方法,它在 packages/runtime-dom/src/index.ts 中实现
export const createApp = ((...args) => {
const app = ensureRenderer().createApp(...args)
if (__DEV__) {
injectNativeTagCheck(app)
}
const { mount } = app
app.mount = (containerOrSelector: Element | string): any => {
const container = normalizeContainer(containerOrSelector)
if (!container) return
const component = app._component
if (!isFunction(component) && !component.render && !component.template) {
component.template = container.innerHTML
}
// clear content before mounting
container.innerHTML = ''
const proxy = mount(container)
container.removeAttribute('v-cloak')
container.setAttribute('data-v-app', '')
return proxy
}
return app
}) as CreateAppFunction<Element>
接受的参数为可变参数,最终通过 ensureRenderer
来创建 app。
const app = ensureRenderer().createApp(...args)
ensureRenderer
是一个函数,我们看看它的具体实现:
// lazy create the renderer - this makes core renderer logic tree-shakable
// in case the user only imports reactivity utilities from Vue.
let renderer: Renderer<Element> | HydrationRenderer
function ensureRenderer() {
return renderer || (renderer = createRenderer<Node, Element>(rendererOptions))
}
ensureRenderer = ensure + renderer,也就是保证这个 renderer 一定会有值,如果 renderer 没有值的时候会通过 createRenderer 这个函数来创建。
这句话是什么意思?
let renderer: Renderer<Element> | HydrationRenderer
createRenderer 最终实现是在 packages/runtime-core/renderer.ts,通过名字可以知道 renderer 是和渲染相关的。哪如何创建一个 renderer 呢?这代码就太长了。一块感受一下:
创建 render 这个函数真的太复杂了。但是这函数的关键为操作 DOM 做好准备,你想啊!DOM 有多少中类型的节点,那么它就会有多少中类似的节点操作函数。
function baseCreateRenderer(
options: RendererOptions,
createHydrationFns?: typeof createHydrationFunctions
): any {
// compile-time feature flags check
if (__ESM_BUNDLER__ && !__TEST__) {
initFeatureFlags()
}
const {
insert: hostInsert,
remove: hostRemove,
patchProp: hostPatchProp,
forcePatchProp: hostForcePatchProp,
createElement: hostCreateElement,
createText: hostCreateText,
createComment: hostCreateComment,
setText: hostSetText,
setElementText: hostSetElementText,
parentNode: hostParentNode,
nextSibling: hostNextSibling,
setScopeId: hostSetScopeId = NOOP,
cloneNode: hostCloneNode,
insertStaticContent: hostInsertStaticContent
} = options
// Note: functions inside this closure should use `const xxx = () => {}`
// style in order to prevent being inlined by minifiers.
const patch: PatchFn = (
n1,
n2,
container,
anchor = null,
parentComponent = null,
parentSuspense = null,
isSVG = false,
optimized = false
) => {
// patching & not same type, unmount old tree
if (n1 && !isSameVNodeType(n1, n2)) {
anchor = getNextHostNode(n1)
unmount(n1, parentComponent, parentSuspense, true)
n1 = null
}
if (n2.patchFlag === PatchFlags.BAIL) {
optimized = false
n2.dynamicChildren = null
}
const { type, ref, shapeFlag } = n2
switch (type) {
case Text:
processText(n1, n2, container, anchor)
break
case Comment:
processCommentNode(n1, n2, container, anchor)
break
case Static:
if (n1 == null) {
mountStaticNode(n2, container, anchor, isSVG)
} else if (__DEV__) {
patchStaticNode(n1, n2, container, isSVG)
}
break
case Fragment:
processFragment(
n1,
n2,
container,
anchor,
parentComponent,
parentSuspense,
isSVG,
optimized
)
break
default:
if (shapeFlag & ShapeFlags.ELEMENT) {
processElement(
n1,
n2,
container,
anchor,
parentComponent,
parentSuspense,
isSVG,
optimized
)
} else if (shapeFlag & ShapeFlags.COMPONENT) {
processComponent(
n1,
n2,
container,
anchor,
parentComponent,
parentSuspense,
isSVG,
optimized
)
} else if (shapeFlag & ShapeFlags.TELEPORT) {
;(type as typeof TeleportImpl).process(
n1 as TeleportVNode,
n2 as TeleportVNode,
container,
anchor,
parentComponent,
parentSuspense,
isSVG,
optimized,
internals
)
} else if (__FEATURE_SUSPENSE__ && shapeFlag & ShapeFlags.SUSPENSE) {
;(type as typeof SuspenseImpl).process(
n1,
n2,
container,
anchor,
parentComponent,
parentSuspense,
isSVG,
optimized,
internals
)
} else if (__DEV__) {
warn('Invalid VNode type:', type, `(${typeof type})`)
}
}
// set ref
if (ref != null && parentComponent) {
setRef(ref, n1 && n1.ref, parentComponent, parentSuspense, n2)
}
}
const processText: ProcessTextOrCommentFn = (n1, n2, container, anchor) => {
if (n1 == null) {
hostInsert(
(n2.el = hostCreateText(n2.children as string)),
container,
anchor
)
} else {
const el = (n2.el = n1.el!)
if (n2.children !== n1.children) {
hostSetText(el, n2.children as string)
}
}
}
const processCommentNode: ProcessTextOrCommentFn = (
n1,
n2,
container,
anchor
) => {
if (n1 == null) {
hostInsert(
(n2.el = hostCreateComment((n2.children as string) || '')),
container,
anchor
)
} else {
// there's no support for dynamic comments
n2.el = n1.el
}
}
const mountStaticNode = (
n2: VNode,
container: RendererElement,
anchor: RendererNode | null,
isSVG: boolean
) => {
// static nodes are only present when used with compiler-dom/runtime-dom
// which guarantees presence of hostInsertStaticContent.
;[n2.el, n2.anchor] = hostInsertStaticContent!(
n2.children as string,
container,
anchor,
isSVG
)
}
/**
* Dev / HMR only
*/
const patchStaticNode = (
n1: VNode,
n2: VNode,
container: RendererElement,
isSVG: boolean
) => {
// static nodes are only patched during dev for HMR
if (n2.children !== n1.children) {
const anchor = hostNextSibling(n1.anchor!)
// remove existing
removeStaticNode(n1)
// insert new
;[n2.el, n2.anchor] = hostInsertStaticContent!(
n2.children as string,
container,
anchor,
isSVG
)
} else {
n2.el = n1.el
n2.anchor = n1.anchor
}
}
/**
* Dev / HMR only
*/
const moveStaticNode = (
vnode: VNode,
container: RendererElement,
anchor: RendererNode | null
) => {
let cur = vnode.el
const end = vnode.anchor!
while (cur && cur !== end) {
const next = hostNextSibling(cur)
hostInsert(cur, container, anchor)
cur = next
}
hostInsert(end, container, anchor)
}
/**
* Dev / HMR only
*/
const removeStaticNode = (vnode: VNode) => {
let cur = vnode.el
while (cur && cur !== vnode.anchor) {
const next = hostNextSibling(cur)
hostRemove(cur)
cur = next
}
hostRemove(vnode.anchor!)
}
const processElement = (
n1: VNode | null,
n2: VNode,
container: RendererElement,
anchor: RendererNode | null,
parentComponent: ComponentInternalInstance | null,
parentSuspense: SuspenseBoundary | null,
isSVG: boolean,
optimized: boolean
) => {
isSVG = isSVG || (n2.type as string) === 'svg'
if (n1 == null) {
mountElement(
n2,
container,
anchor,
parentComponent,
parentSuspense,
isSVG,
optimized
)
} else {
patchElement(n1, n2, parentComponent, parentSuspense, isSVG, optimized)
}
}
const mountElement = (
vnode: VNode,
container: RendererElement,
anchor: RendererNode | null,
parentComponent: ComponentInternalInstance | null,
parentSuspense: SuspenseBoundary | null,
isSVG: boolean,
optimized: boolean
) => {
let el: RendererElement
let vnodeHook: VNodeHook | undefined | null
const {
type,
props,
shapeFlag,
transition,
scopeId,
patchFlag,
dirs
} = vnode
if (
!__DEV__ &&
vnode.el &&
hostCloneNode !== undefined &&
patchFlag === PatchFlags.HOISTED
) {
// If a vnode has non-null el, it means it's being reused.
// Only static vnodes can be reused, so its mounted DOM nodes should be
// exactly the same, and we can simply do a clone here.
// only do this in production since cloned trees cannot be HMR updated.
el = vnode.el = hostCloneNode(vnode.el)
} else {
el = vnode.el = hostCreateElement(
vnode.type as string,
isSVG,
props && props.is
)
// mount children first, since some props may rely on child content
// being already rendered, e.g. `<select value>`
if (shapeFlag & ShapeFlags.TEXT_CHILDREN) {
hostSetElementText(el, vnode.children as string)
} else if (shapeFlag & ShapeFlags.ARRAY_CHILDREN) {
mountChildren(
vnode.children as VNodeArrayChildren,
el,
null,
parentComponent,
parentSuspense,
isSVG && type !== 'foreignObject',
optimized || !!vnode.dynamicChildren
)
}
if (dirs) {
invokeDirectiveHook(vnode, null, parentComponent, 'created')
}
// props
if (props) {
for (const key in props) {
if (!isReservedProp(key)) {
hostPatchProp(
el,
key,
null,
props[key],
isSVG,
vnode.children as VNode[],
parentComponent,
parentSuspense,
unmountChildren
)
}
}
if ((vnodeHook = props.onVnodeBeforeMount)) {
invokeVNodeHook(vnodeHook, parentComponent, vnode)
}
}
// scopeId
setScopeId(el, scopeId, vnode, parentComponent)
// if (scopeId) {
// hostSetScopeId(el, scopeId)
// }
// if (parentComponent) {
// const treeOwnerId = parentComponent.type.__scopeId
// // vnode's own scopeId and the current patched component's scopeId is
// // different - this is a slot content node.
// if (treeOwnerId && treeOwnerId !== scopeId) {
// hostSetScopeId(el, treeOwnerId + '-s')
// }
// const parentScopeId =
// vnode === parentComponent.subTree && parentComponent.vnode.scopeId
// if (parentScopeId) {
// hostSetScopeId(el, parentScopeId)
// if (parentComponent.parent) {
// const treeOwnerId = parentComponent.parent.type.__scopeId
// // vnode's own scopeId and the current patched component's scopeId is
// // different - this is a slot content node.
// if (treeOwnerId && treeOwnerId !== parentScopeId) {
// hostSetScopeId(el, treeOwnerId + '-s')
// }
// }
// }
// }
}
if (__DEV__ || __FEATURE_PROD_DEVTOOLS__) {
Object.defineProperty(el, '__vnode', {
value: vnode,
enumerable: false
})
Object.defineProperty(el, '__vueParentComponent', {
value: parentComponent,
enumerable: false
})
}
if (dirs) {
invokeDirectiveHook(vnode, null, parentComponent, 'beforeMount')
}
// #1583 For inside suspense + suspense not resolved case, enter hook should call when suspense resolved
// #1689 For inside suspense + suspense resolved case, just call it
const needCallTransitionHooks =
(!parentSuspense || (parentSuspense && parentSuspense!.isResolved)) &&
transition &&
!transition.persisted
if (needCallTransitionHooks) {
transition!.beforeEnter(el)
}
hostInsert(el, container, anchor)
if (
(vnodeHook = props && props.onVnodeMounted) ||
needCallTransitionHooks ||
dirs
) {
queuePostRenderEffect(() => {
vnodeHook && invokeVNodeHook(vnodeHook, parentComponent, vnode)
needCallTransitionHooks && transition!.enter(el)
dirs && invokeDirectiveHook(vnode, null, parentComponent, 'mounted')
}, parentSuspense)
}
}
const setScopeId = (
el: RendererElement,
scopeId: string | false | null,
vnode: VNode,
parentComponent: ComponentInternalInstance | null
) => {
if (scopeId) {
hostSetScopeId(el, scopeId)
}
if (parentComponent) {
const treeOwnerId = parentComponent.type.__scopeId
// vnode's own scopeId and the current patched component's scopeId is
// different - this is a slot content node.
if (treeOwnerId && treeOwnerId !== scopeId) {
hostSetScopeId(el, treeOwnerId + '-s')
}
if (vnode === parentComponent.subTree) {
setScopeId(
el,
parentComponent.vnode.scopeId,
parentComponent.vnode,
parentComponent.parent
)
}
}
}
const mountChildren: MountChildrenFn = (
children,
container,
anchor,
parentComponent,
parentSuspense,
isSVG,
optimized,
start = 0
) => {
for (let i = start; i < children.length; i++) {
const child = (children[i] = optimized
? cloneIfMounted(children[i] as VNode)
: normalizeVNode(children[i]))
patch(
null,
child,
container,
anchor,
parentComponent,
parentSuspense,
isSVG,
optimized
)
}
}
const patchElement = (
n1: VNode,
n2: VNode,
parentComponent: ComponentInternalInstance | null,
parentSuspense: SuspenseBoundary | null,
isSVG: boolean,
optimized: boolean
) => {
const el = (n2.el = n1.el!)
let { patchFlag, dynamicChildren, dirs } = n2
// #1426 take the old vnode's patch flag into account since user may clone a
// compiler-generated vnode, which de-opts to FULL_PROPS
patchFlag |= n1.patchFlag & PatchFlags.FULL_PROPS
const oldProps = n1.props || EMPTY_OBJ
const newProps = n2.props || EMPTY_OBJ
let vnodeHook: VNodeHook | undefined | null
if ((vnodeHook = newProps.onVnodeBeforeUpdate)) {
invokeVNodeHook(vnodeHook, parentComponent, n2, n1)
}
if (dirs) {
invokeDirectiveHook(n2, n1, parentComponent, 'beforeUpdate')
}
if (__DEV__ && isHmrUpdating) {
// HMR updated, force full diff
patchFlag = 0
optimized = false
dynamicChildren = null
}
if (patchFlag > 0) {
// the presence of a patchFlag means this element's render code was
// generated by the compiler and can take the fast path.
// in this path old node and new node are guaranteed to have the same shape
// (i.e. at the exact same position in the source template)
if (patchFlag & PatchFlags.FULL_PROPS) {
// element props contain dynamic keys, full diff needed
patchProps(
el,
n2,
oldProps,
newProps,
parentComponent,
parentSuspense,
isSVG
)
} else {
// class
// this flag is matched when the element has dynamic class bindings.
if (patchFlag & PatchFlags.CLASS) {
if (oldProps.class !== newProps.class) {
hostPatchProp(el, 'class', null, newProps.class, isSVG)
}
}
// style
// this flag is matched when the element has dynamic style bindings
if (patchFlag & PatchFlags.STYLE) {
hostPatchProp(el, 'style', oldProps.style, newProps.style, isSVG)
}
// props
// This flag is matched when the element has dynamic prop/attr bindings
// other than class and style. The keys of dynamic prop/attrs are saved for
// faster iteration.
// Note dynamic keys like :[foo]="bar" will cause this optimization to
// bail out and go through a full diff because we need to unset the old key
if (patchFlag & PatchFlags.PROPS) {
// if the flag is present then dynamicProps must be non-null
const propsToUpdate = n2.dynamicProps!
for (let i = 0; i < propsToUpdate.length; i++) {
const key = propsToUpdate[i]
const prev = oldProps[key]
const next = newProps[key]
if (
next !== prev ||
(hostForcePatchProp && hostForcePatchProp(el, key))
) {
hostPatchProp(
el,
key,
prev,
next,
isSVG,
n1.children as VNode[],
parentComponent,
parentSuspense,
unmountChildren
)
}
}
}
}
// text
// This flag is matched when the element has only dynamic text children.
if (patchFlag & PatchFlags.TEXT) {
if (n1.children !== n2.children) {
hostSetElementText(el, n2.children as string)
}
}
} else if (!optimized && dynamicChildren == null) {
// unoptimized, full diff
patchProps(
el,
n2,
oldProps,
newProps,
parentComponent,
parentSuspense,
isSVG
)
}
const areChildrenSVG = isSVG && n2.type !== 'foreignObject'
if (dynamicChildren) {
patchBlockChildren(
n1.dynamicChildren!,
dynamicChildren,
el,
parentComponent,
parentSuspense,
areChildrenSVG
)
if (__DEV__ && parentComponent && parentComponent.type.__hmrId) {
traverseStaticChildren(n1, n2)
}
} else if (!optimized) {
// full diff
patchChildren(
n1,
n2,
el,
null,
parentComponent,
parentSuspense,
areChildrenSVG
)
}
if ((vnodeHook = newProps.onVnodeUpdated) || dirs) {
queuePostRenderEffect(() => {
vnodeHook && invokeVNodeHook(vnodeHook, parentComponent, n2, n1)
dirs && invokeDirectiveHook(n2, n1, parentComponent, 'updated')
}, parentSuspense)
}
}
// The fast path for blocks.
const patchBlockChildren: PatchBlockChildrenFn = (
oldChildren,
newChildren,
fallbackContainer,
parentComponent,
parentSuspense,
isSVG
) => {
for (let i = 0; i < newChildren.length; i++) {
const oldVNode = oldChildren[i]
const newVNode = newChildren[i]
// Determine the container (parent element) for the patch.
const container =
// - In the case of a Fragment, we need to provide the actual parent
// of the Fragment itself so it can move its children.
oldVNode.type === Fragment ||
// - In the case of different nodes, there is going to be a replacement
// which also requires the correct parent container
!isSameVNodeType(oldVNode, newVNode) ||
// - In the case of a component, it could contain anything.
oldVNode.shapeFlag & ShapeFlags.COMPONENT ||
oldVNode.shapeFlag & ShapeFlags.TELEPORT
? hostParentNode(oldVNode.el!)!
: // In other cases, the parent container is not actually used so we
// just pass the block element here to avoid a DOM parentNode call.
fallbackContainer
patch(
oldVNode,
newVNode,
container,
null,
parentComponent,
parentSuspense,
isSVG,
true
)
}
}
const patchProps = (
el: RendererElement,
vnode: VNode,
oldProps: Data,
newProps: Data,
parentComponent: ComponentInternalInstance | null,
parentSuspense: SuspenseBoundary | null,
isSVG: boolean
) => {
if (oldProps !== newProps) {
for (const key in newProps) {
if (isReservedProp(key)) continue
const next = newProps[key]
const prev = oldProps[key]
if (
next !== prev ||
(hostForcePatchProp && hostForcePatchProp(el, key))
) {
hostPatchProp(
el,
key,
prev,
next,
isSVG,
vnode.children as VNode[],
parentComponent,
parentSuspense,
unmountChildren
)
}
}
if (oldProps !== EMPTY_OBJ) {
for (const key in oldProps) {
if (!isReservedProp(key) && !(key in newProps)) {
hostPatchProp(
el,
key,
oldProps[key],
null,
isSVG,
vnode.children as VNode[],
parentComponent,
parentSuspense,
unmountChildren
)
}
}
}
}
}
const processFragment = (
n1: VNode | null,
n2: VNode,
container: RendererElement,
anchor: RendererNode | null,
parentComponent: ComponentInternalInstance | null,
parentSuspense: SuspenseBoundary | null,
isSVG: boolean,
optimized: boolean
) => {
const fragmentStartAnchor = (n2.el = n1 ? n1.el : hostCreateText(''))!
const fragmentEndAnchor = (n2.anchor = n1 ? n1.anchor : hostCreateText(''))!
let { patchFlag, dynamicChildren } = n2
if (patchFlag > 0) {
optimized = true
}
if (__DEV__ && isHmrUpdating) {
// HMR updated, force full diff
patchFlag = 0
optimized = false
dynamicChildren = null
}
if (n1 == null) {
hostInsert(fragmentStartAnchor, container, anchor)
hostInsert(fragmentEndAnchor, container, anchor)
// a fragment can only have array children
// since they are either generated by the compiler, or implicitly created
// from arrays.
mountChildren(
n2.children as VNodeArrayChildren,
container,
fragmentEndAnchor,
parentComponent,
parentSuspense,
isSVG,
optimized
)
} else {
if (
patchFlag > 0 &&
patchFlag & PatchFlags.STABLE_FRAGMENT &&
dynamicChildren
) {
// a stable fragment (template root or <template v-for>) doesn't need to
// patch children order, but it may contain dynamicChildren.
patchBlockChildren(
n1.dynamicChildren!,
dynamicChildren,
container,
parentComponent,
parentSuspense,
isSVG
)
if (__DEV__ && parentComponent && parentComponent.type.__hmrId) {
traverseStaticChildren(n1, n2)
}
} else {
// keyed / unkeyed, or manual fragments.
// for keyed & unkeyed, since they are compiler generated from v-for,
// each child is guaranteed to be a block so the fragment will never
// have dynamicChildren.
patchChildren(
n1,
n2,
container,
fragmentEndAnchor,
parentComponent,
parentSuspense,
isSVG,
optimized
)
}
}
}
const processComponent = (
n1: VNode | null,
n2: VNode,
container: RendererElement,
anchor: RendererNode | null,
parentComponent: ComponentInternalInstance | null,
parentSuspense: SuspenseBoundary | null,
isSVG: boolean,
optimized: boolean
) => {
if (n1 == null) {
if (n2.shapeFlag & ShapeFlags.COMPONENT_KEPT_ALIVE) {
;(parentComponent!.ctx as KeepAliveContext).activate(
n2,
container,
anchor,
isSVG,
optimized
)
} else {
mountComponent(
n2,
container,
anchor,
parentComponent,
parentSuspense,
isSVG,
optimized
)
}
} else {
updateComponent(n1, n2, optimized)
}
}
const mountComponent: MountComponentFn = (
initialVNode,
container,
anchor,
parentComponent,
parentSuspense,
isSVG,
optimized
) => {
const instance: ComponentInternalInstance = (initialVNode.component = createComponentInstance(
initialVNode,
parentComponent,
parentSuspense
))
if (__DEV__ && instance.type.__hmrId) {
registerHMR(instance)
}
if (__DEV__) {
pushWarningContext(initialVNode)
startMeasure(instance, `mount`)
}
// inject renderer internals for keepAlive
if (isKeepAlive(initialVNode)) {
;(instance.ctx as KeepAliveContext).renderer = internals
}
// resolve props and slots for setup context
if (__DEV__) {
startMeasure(instance, `init`)
}
setupComponent(instance)
if (__DEV__) {
endMeasure(instance, `init`)
}
// setup() is async. This component relies on async logic to be resolved
// before proceeding
if (__FEATURE_SUSPENSE__ && instance.asyncDep) {
if (!parentSuspense) {
if (__DEV__) warn('async setup() is used without a suspense boundary!')
return
}
parentSuspense.registerDep(instance, setupRenderEffect)
// Give it a placeholder if this is not hydration
if (!initialVNode.el) {
const placeholder = (instance.subTree = createVNode(Comment))
processCommentNode(null, placeholder, container!, anchor)
}
return
}
setupRenderEffect(
instance,
initialVNode,
container,
anchor,
parentSuspense,
isSVG,
optimized
)
if (__DEV__) {
popWarningContext()
endMeasure(instance, `mount`)
}
}
const updateComponent = (n1: VNode, n2: VNode, optimized: boolean) => {
const instance = (n2.component = n1.component)!
if (shouldUpdateComponent(n1, n2, optimized)) {
if (
__FEATURE_SUSPENSE__ &&
instance.asyncDep &&
!instance.asyncResolved
) {
// async & still pending - just update props and slots
// since the component's reactive effect for render isn't set-up yet
if (__DEV__) {
pushWarningContext(n2)
}
updateComponentPreRender(instance, n2, optimized)
if (__DEV__) {
popWarningContext()
}
return
} else {
// normal update
instance.next = n2
// in case the child component is also queued, remove it to avoid
// double updating the same child component in the same flush.
invalidateJob(instance.update)
// instance.update is the reactive effect runner.
instance.update()
}
} else {
// no update needed. just copy over properties
n2.component = n1.component
n2.el = n1.el
instance.vnode = n2
}
}
const setupRenderEffect: SetupRenderEffectFn = (
instance,
initialVNode,
container,
anchor,
parentSuspense,
isSVG,
optimized
) => {
// create reactive effect for rendering
instance.update = effect(function componentEffect() {
if (!instance.isMounted) {
let vnodeHook: VNodeHook | null | undefined
const { el, props } = initialVNode
const { bm, m, parent } = instance
// beforeMount hook
if (bm) {
invokeArrayFns(bm)
}
// onVnodeBeforeMount
if ((vnodeHook = props && props.onVnodeBeforeMount)) {
invokeVNodeHook(vnodeHook, parent, initialVNode)
}
// render
if (__DEV__) {
startMeasure(instance, `render`)
}
const subTree = (instance.subTree = renderComponentRoot(instance))
if (__DEV__) {
endMeasure(instance, `render`)
}
if (el && hydrateNode) {
if (__DEV__) {
startMeasure(instance, `hydrate`)
}
// vnode has adopted host node - perform hydration instead of mount.
hydrateNode(
initialVNode.el as Node,
subTree,
instance,
parentSuspense
)
if (__DEV__) {
endMeasure(instance, `hydrate`)
}
} else {
if (__DEV__) {
startMeasure(instance, `patch`)
}
patch(
null,
subTree,
container,
anchor,
instance,
parentSuspense,
isSVG
)
if (__DEV__) {
endMeasure(instance, `patch`)
}
initialVNode.el = subTree.el
}
// mounted hook
if (m) {
queuePostRenderEffect(m, parentSuspense)
}
// onVnodeMounted
if ((vnodeHook = props && props.onVnodeMounted)) {
queuePostRenderEffect(() => {
invokeVNodeHook(vnodeHook!, parent, initialVNode)
}, parentSuspense)
}
// activated hook for keep-alive roots.
// #1742 activated hook must be accessed after first render
// since the hook may be injected by a child keep-alive
const { a } = instance
if (
a &&
initialVNode.shapeFlag & ShapeFlags.COMPONENT_SHOULD_KEEP_ALIVE
) {
queuePostRenderEffect(a, parentSuspense)
}
instance.isMounted = true
} else {
// updateComponent
// This is triggered by mutation of component's own state (next: null)
// OR parent calling processComponent (next: VNode)
let { next, bu, u, parent, vnode } = instance
let originNext = next
let vnodeHook: VNodeHook | null | undefined
if (__DEV__) {
pushWarningContext(next || instance.vnode)
}
if (next) {
updateComponentPreRender(instance, next, optimized)
} else {
next = vnode
}
next.el = vnode.el
// beforeUpdate hook
if (bu) {
invokeArrayFns(bu)
}
// onVnodeBeforeUpdate
if ((vnodeHook = next.props && next.props.onVnodeBeforeUpdate)) {
invokeVNodeHook(vnodeHook, parent, next, vnode)
}
// render
if (__DEV__) {
startMeasure(instance, `render`)
}
const nextTree = renderComponentRoot(instance)
if (__DEV__) {
endMeasure(instance, `render`)
}
const prevTree = instance.subTree
instance.subTree = nextTree
// reset refs
// only needed if previous patch had refs
if (instance.refs !== EMPTY_OBJ) {
instance.refs = {}
}
if (__DEV__) {
startMeasure(instance, `patch`)
}
patch(
prevTree,
nextTree,
// parent may have changed if it's in a teleport
hostParentNode(prevTree.el!)!,
// anchor may have changed if it's in a fragment
getNextHostNode(prevTree),
instance,
parentSuspense,
isSVG
)
if (__DEV__) {
endMeasure(instance, `patch`)
}
next.el = nextTree.el
if (originNext === null) {
// self-triggered update. In case of HOC, update parent component
// vnode el. HOC is indicated by parent instance's subTree pointing
// to child component's vnode
updateHOCHostEl(instance, nextTree.el)
}
// updated hook
if (u) {
queuePostRenderEffect(u, parentSuspense)
}
// onVnodeUpdated
if ((vnodeHook = next.props && next.props.onVnodeUpdated)) {
queuePostRenderEffect(() => {
invokeVNodeHook(vnodeHook!, parent, next!, vnode)
}, parentSuspense)
}
if (__DEV__ || __FEATURE_PROD_DEVTOOLS__) {
devtoolsComponentUpdated(instance)
}
if (__DEV__) {
popWarningContext()
}
}
}, __DEV__ ? createDevEffectOptions(instance) : prodEffectOptions)
// #1801 mark it to allow recursive updates
;(instance.update as SchedulerJob).allowRecurse = true
}
const updateComponentPreRender = (
instance: ComponentInternalInstance,
nextVNode: VNode,
optimized: boolean
) => {
nextVNode.component = instance
const prevProps = instance.vnode.props
instance.vnode = nextVNode
instance.next = null
updateProps(instance, nextVNode.props, prevProps, optimized)
updateSlots(instance, nextVNode.children)
// props update may have triggered pre-flush watchers.
// flush them before the render update.
flushPreFlushCbs(undefined, instance.update)
}
const patchChildren: PatchChildrenFn = (
n1,
n2,
container,
anchor,
parentComponent,
parentSuspense,
isSVG,
optimized = false
) => {
const c1 = n1 && n1.children
const prevShapeFlag = n1 ? n1.shapeFlag : 0
const c2 = n2.children
const { patchFlag, shapeFlag } = n2
// fast path
if (patchFlag > 0) {
if (patchFlag & PatchFlags.KEYED_FRAGMENT) {
// this could be either fully-keyed or mixed (some keyed some not)
// presence of patchFlag means children are guaranteed to be arrays
patchKeyedChildren(
c1 as VNode[],
c2 as VNodeArrayChildren,
container,
anchor,
parentComponent,
parentSuspense,
isSVG,
optimized
)
return
} else if (patchFlag & PatchFlags.UNKEYED_FRAGMENT) {
// unkeyed
patchUnkeyedChildren(
c1 as VNode[],
c2 as VNodeArrayChildren,
container,
anchor,
parentComponent,
parentSuspense,
isSVG,
optimized
)
return
}
}
// children has 3 possibilities: text, array or no children.
if (shapeFlag & ShapeFlags.TEXT_CHILDREN) {
// text children fast path
if (prevShapeFlag & ShapeFlags.ARRAY_CHILDREN) {
unmountChildren(c1 as VNode[], parentComponent, parentSuspense)
}
if (c2 !== c1) {
hostSetElementText(container, c2 as string)
}
} else {
if (prevShapeFlag & ShapeFlags.ARRAY_CHILDREN) {
// prev children was array
if (shapeFlag & ShapeFlags.ARRAY_CHILDREN) {
// two arrays, cannot assume anything, do full diff
patchKeyedChildren(
c1 as VNode[],
c2 as VNodeArrayChildren,
container,
anchor,
parentComponent,
parentSuspense,
isSVG,
optimized
)
} else {
// no new children, just unmount old
unmountChildren(c1 as VNode[], parentComponent, parentSuspense, true)
}
} else {
// prev children was text OR null
// new children is array OR null
if (prevShapeFlag & ShapeFlags.TEXT_CHILDREN) {
hostSetElementText(container, '')
}
// mount new if array
if (shapeFlag & ShapeFlags.ARRAY_CHILDREN) {
mountChildren(
c2 as VNodeArrayChildren,
container,
anchor,
parentComponent,
parentSuspense,
isSVG,
optimized
)
}
}
}
}
const patchUnkeyedChildren = (
c1: VNode[],
c2: VNodeArrayChildren,
container: RendererElement,
anchor: RendererNode | null,
parentComponent: ComponentInternalInstance | null,
parentSuspense: SuspenseBoundary | null,
isSVG: boolean,
optimized: boolean
) => {
c1 = c1 || EMPTY_ARR
c2 = c2 || EMPTY_ARR
const oldLength = c1.length
const newLength = c2.length
const commonLength = Math.min(oldLength, newLength)
let i
for (i = 0; i < commonLength; i++) {
const nextChild = (c2[i] = optimized
? cloneIfMounted(c2[i] as VNode)
: normalizeVNode(c2[i]))
patch(
c1[i],
nextChild,
container,
null,
parentComponent,
parentSuspense,
isSVG,
optimized
)
}
if (oldLength > newLength) {
// remove old
unmountChildren(c1, parentComponent, parentSuspense, true, commonLength)
} else {
// mount new
mountChildren(
c2,
container,
anchor,
parentComponent,
parentSuspense,
isSVG,
optimized,
commonLength
)
}
}
// can be all-keyed or mixed
const patchKeyedChildren = (
c1: VNode[],
c2: VNodeArrayChildren,
container: RendererElement,
parentAnchor: RendererNode | null,
parentComponent: ComponentInternalInstance | null,
parentSuspense: SuspenseBoundary | null,
isSVG: boolean,
optimized: boolean
) => {
let i = 0
const l2 = c2.length
let e1 = c1.length - 1 // prev ending index
let e2 = l2 - 1 // next ending index
// 1. sync from start
// (a b) c
// (a b) d e
while (i <= e1 && i <= e2) {
const n1 = c1[i]
const n2 = (c2[i] = optimized
? cloneIfMounted(c2[i] as VNode)
: normalizeVNode(c2[i]))
if (isSameVNodeType(n1, n2)) {
patch(
n1,
n2,
container,
null,
parentComponent,
parentSuspense,
isSVG,
optimized
)
} else {
break
}
i++
}
// 2. sync from end
// a (b c)
// d e (b c)
while (i <= e1 && i <= e2) {
const n1 = c1[e1]
const n2 = (c2[e2] = optimized
? cloneIfMounted(c2[e2] as VNode)
: normalizeVNode(c2[e2]))
if (isSameVNodeType(n1, n2)) {
patch(
n1,
n2,
container,
null,
parentComponent,
parentSuspense,
isSVG,
optimized
)
} else {
break
}
e1--
e2--
}
// 3. common sequence + mount
// (a b)
// (a b) c
// i = 2, e1 = 1, e2 = 2
// (a b)
// c (a b)
// i = 0, e1 = -1, e2 = 0
if (i > e1) {
if (i <= e2) {
const nextPos = e2 + 1
const anchor = nextPos < l2 ? (c2[nextPos] as VNode).el : parentAnchor
while (i <= e2) {
patch(
null,
(c2[i] = optimized
? cloneIfMounted(c2[i] as VNode)
: normalizeVNode(c2[i])),
container,
anchor,
parentComponent,
parentSuspense,
isSVG
)
i++
}
}
}
// 4. common sequence + unmount
// (a b) c
// (a b)
// i = 2, e1 = 2, e2 = 1
// a (b c)
// (b c)
// i = 0, e1 = 0, e2 = -1
else if (i > e2) {
while (i <= e1) {
unmount(c1[i], parentComponent, parentSuspense, true)
i++
}
}
// 5. unknown sequence
// [i ... e1 + 1]: a b [c d e] f g
// [i ... e2 + 1]: a b [e d c h] f g
// i = 2, e1 = 4, e2 = 5
else {
const s1 = i // prev starting index
const s2 = i // next starting index
// 5.1 build key:index map for newChildren
const keyToNewIndexMap: Map<string | number, number> = new Map()
for (i = s2; i <= e2; i++) {
const nextChild = (c2[i] = optimized
? cloneIfMounted(c2[i] as VNode)
: normalizeVNode(c2[i]))
if (nextChild.key != null) {
if (__DEV__ && keyToNewIndexMap.has(nextChild.key)) {
warn(
`Duplicate keys found during update:`,
JSON.stringify(nextChild.key),
`Make sure keys are unique.`
)
}
keyToNewIndexMap.set(nextChild.key, i)
}
}
// 5.2 loop through old children left to be patched and try to patch
// matching nodes & remove nodes that are no longer present
let j
let patched = 0
const toBePatched = e2 - s2 + 1
let moved = false
// used to track whether any node has moved
let maxNewIndexSoFar = 0
// works as Map<newIndex, oldIndex>
// Note that oldIndex is offset by +1
// and oldIndex = 0 is a special value indicating the new node has
// no corresponding old node.
// used for determining longest stable subsequence
const newIndexToOldIndexMap = new Array(toBePatched)
for (i = 0; i < toBePatched; i++) newIndexToOldIndexMap[i] = 0
for (i = s1; i <= e1; i++) {
const prevChild = c1[i]
if (patched >= toBePatched) {
// all new children have been patched so this can only be a removal
unmount(prevChild, parentComponent, parentSuspense, true)
continue
}
let newIndex
if (prevChild.key != null) {
newIndex = keyToNewIndexMap.get(prevChild.key)
} else {
// key-less node, try to locate a key-less node of the same type
for (j = s2; j <= e2; j++) {
if (
newIndexToOldIndexMap[j - s2] === 0 &&
isSameVNodeType(prevChild, c2[j] as VNode)
) {
newIndex = j
break
}
}
}
if (newIndex === undefined) {
unmount(prevChild, parentComponent, parentSuspense, true)
} else {
newIndexToOldIndexMap[newIndex - s2] = i + 1
if (newIndex >= maxNewIndexSoFar) {
maxNewIndexSoFar = newIndex
} else {
moved = true
}
patch(
prevChild,
c2[newIndex] as VNode,
container,
null,
parentComponent,
parentSuspense,
isSVG,
optimized
)
patched++
}
}
// 5.3 move and mount
// generate longest stable subsequence only when nodes have moved
const increasingNewIndexSequence = moved
? getSequence(newIndexToOldIndexMap)
: EMPTY_ARR
j = increasingNewIndexSequence.length - 1
// looping backwards so that we can use last patched node as anchor
for (i = toBePatched - 1; i >= 0; i--) {
const nextIndex = s2 + i
const nextChild = c2[nextIndex] as VNode
const anchor =
nextIndex + 1 < l2 ? (c2[nextIndex + 1] as VNode).el : parentAnchor
if (newIndexToOldIndexMap[i] === 0) {
// mount new
patch(
null,
nextChild,
container,
anchor,
parentComponent,
parentSuspense,
isSVG
)
} else if (moved) {
// move if:
// There is no stable subsequence (e.g. a reverse)
// OR current node is not among the stable sequence
if (j < 0 || i !== increasingNewIndexSequence[j]) {
move(nextChild, container, anchor, MoveType.REORDER)
} else {
j--
}
}
}
}
}
const move: MoveFn = (
vnode,
container,
anchor,
moveType,
parentSuspense = null
) => {
const { el, type, transition, children, shapeFlag } = vnode
if (shapeFlag & ShapeFlags.COMPONENT) {
move(vnode.component!.subTree, container, anchor, moveType)
return
}
if (__FEATURE_SUSPENSE__ && shapeFlag & ShapeFlags.SUSPENSE) {
vnode.suspense!.move(container, anchor, moveType)
return
}
if (shapeFlag & ShapeFlags.TELEPORT) {
;(type as typeof TeleportImpl).move(vnode, container, anchor, internals)
return
}
if (type === Fragment) {
hostInsert(el!, container, anchor)
for (let i = 0; i < (children as VNode[]).length; i++) {
move((children as VNode[])[i], container, anchor, moveType)
}
hostInsert(vnode.anchor!, container, anchor)
return
}
// static node move can only happen when force updating HMR
if (__DEV__ && type === Static) {
moveStaticNode(vnode, container, anchor)
return
}
// single nodes
const needTransition =
moveType !== MoveType.REORDER &&
shapeFlag & ShapeFlags.ELEMENT &&
transition
if (needTransition) {
if (moveType === MoveType.ENTER) {
transition!.beforeEnter(el!)
hostInsert(el!, container, anchor)
queuePostRenderEffect(() => transition!.enter(el!), parentSuspense)
} else {
const { leave, delayLeave, afterLeave } = transition!
const remove = () => hostInsert(el!, container, anchor)
const performLeave = () => {
leave(el!, () => {
remove()
afterLeave && afterLeave()
})
}
if (delayLeave) {
delayLeave(el!, remove, performLeave)
} else {
performLeave()
}
}
} else {
hostInsert(el!, container, anchor)
}
}
const unmount: UnmountFn = (
vnode,
parentComponent,
parentSuspense,
doRemove = false
) => {
const {
type,
props,
ref,
children,
dynamicChildren,
shapeFlag,
patchFlag,
dirs
} = vnode
// unset ref
if (ref != null && parentComponent) {
setRef(ref, null, parentComponent, parentSuspense, null)
}
if (shapeFlag & ShapeFlags.COMPONENT_SHOULD_KEEP_ALIVE) {
;(parentComponent!.ctx as KeepAliveContext).deactivate(vnode)
return
}
const shouldInvokeDirs = shapeFlag & ShapeFlags.ELEMENT && dirs
let vnodeHook: VNodeHook | undefined | null
if ((vnodeHook = props && props.onVnodeBeforeUnmount)) {
invokeVNodeHook(vnodeHook, parentComponent, vnode)
}
if (shapeFlag & ShapeFlags.COMPONENT) {
unmountComponent(vnode.component!, parentSuspense, doRemove)
} else {
if (__FEATURE_SUSPENSE__ && shapeFlag & ShapeFlags.SUSPENSE) {
vnode.suspense!.unmount(parentSuspense, doRemove)
return
}
if (shouldInvokeDirs) {
invokeDirectiveHook(vnode, null, parentComponent, 'beforeUnmount')
}
if (
dynamicChildren &&
// #1153: fast path should not be taken for non-stable (v-for) fragments
(type !== Fragment ||
(patchFlag > 0 && patchFlag & PatchFlags.STABLE_FRAGMENT))
) {
// fast path for block nodes: only need to unmount dynamic children.
unmountChildren(dynamicChildren, parentComponent, parentSuspense)
} else if (shapeFlag & ShapeFlags.ARRAY_CHILDREN) {
unmountChildren(children as VNode[], parentComponent, parentSuspense)
}
// an unmounted teleport should always remove its children
if (shapeFlag & ShapeFlags.TELEPORT) {
;(vnode.type as typeof TeleportImpl).remove(vnode, internals)
}
if (doRemove) {
remove(vnode)
}
}
if ((vnodeHook = props && props.onVnodeUnmounted) || shouldInvokeDirs) {
queuePostRenderEffect(() => {
vnodeHook && invokeVNodeHook(vnodeHook, parentComponent, vnode)
shouldInvokeDirs &&
invokeDirectiveHook(vnode, null, parentComponent, 'unmounted')
}, parentSuspense)
}
}
const remove: RemoveFn = vnode => {
const { type, el, anchor, transition } = vnode
if (type === Fragment) {
removeFragment(el!, anchor!)
return
}
if (__DEV__ && type === Static) {
removeStaticNode(vnode)
return
}
const performRemove = () => {
hostRemove(el!)
if (transition && !transition.persisted && transition.afterLeave) {
transition.afterLeave()
}
}
if (
vnode.shapeFlag & ShapeFlags.ELEMENT &&
transition &&
!transition.persisted
) {
const { leave, delayLeave } = transition
const performLeave = () => leave(el!, performRemove)
if (delayLeave) {
delayLeave(vnode.el!, performRemove, performLeave)
} else {
performLeave()
}
} else {
performRemove()
}
}
const removeFragment = (cur: RendererNode, end: RendererNode) => {
// For fragments, directly remove all contained DOM nodes.
// (fragment child nodes cannot have transition)
let next
while (cur !== end) {
next = hostNextSibling(cur)!
hostRemove(cur)
cur = next
}
hostRemove(end)
}
const unmountComponent = (
instance: ComponentInternalInstance,
parentSuspense: SuspenseBoundary | null,
doRemove?: boolean
) => {
if (__DEV__ && instance.type.__hmrId) {
unregisterHMR(instance)
}
const { bum, effects, update, subTree, um } = instance
// beforeUnmount hook
if (bum) {
invokeArrayFns(bum)
}
if (effects) {
for (let i = 0; i < effects.length; i++) {
stop(effects[i])
}
}
// update may be null if a component is unmounted before its async
// setup has resolved.
if (update) {
stop(update)
unmount(subTree, instance, parentSuspense, doRemove)
}
// unmounted hook
if (um) {
queuePostRenderEffect(um, parentSuspense)
}
queuePostRenderEffect(() => {
instance.isUnmounted = true
}, parentSuspense)
// A component with async dep inside a pending suspense is unmounted before
// its async dep resolves. This should remove the dep from the suspense, and
// cause the suspense to resolve immediately if that was the last dep.
if (
__FEATURE_SUSPENSE__ &&
parentSuspense &&
!parentSuspense.isResolved &&
!parentSuspense.isUnmounted &&
instance.asyncDep &&
!instance.asyncResolved
) {
parentSuspense.deps--
if (parentSuspense.deps === 0) {
parentSuspense.resolve()
}
}
if (__DEV__ || __FEATURE_PROD_DEVTOOLS__) {
devtoolsComponentRemoved(instance)
}
}
const unmountChildren: UnmountChildrenFn = (
children,
parentComponent,
parentSuspense,
doRemove = false,
start = 0
) => {
for (let i = start; i < children.length; i++) {
unmount(children[i], parentComponent, parentSuspense, doRemove)
}
}
const getNextHostNode: NextFn = vnode => {
if (vnode.shapeFlag & ShapeFlags.COMPONENT) {
return getNextHostNode(vnode.component!.subTree)
}
if (__FEATURE_SUSPENSE__ && vnode.shapeFlag & ShapeFlags.SUSPENSE) {
return vnode.suspense!.next()
}
return hostNextSibling((vnode.anchor || vnode.el)!)
}
/**
* #1156
* When a component is HMR-enabled, we need to make sure that all static nodes
* inside a block also inherit the DOM element from the previous tree so that
* HMR updates (which are full updates) can retrieve the element for patching.
*
* Dev only.
*/
const traverseStaticChildren = (n1: VNode, n2: VNode) => {
const ch1 = n1.children
const ch2 = n2.children
if (isArray(ch1) && isArray(ch2)) {
for (let i = 0; i < ch1.length; i++) {
// this is only called in the optimized path so array children are
// guaranteed to be vnodes
const c1 = ch1[i] as VNode
const c2 = (ch2[i] = cloneIfMounted(ch2[i] as VNode))
if (c2.shapeFlag & ShapeFlags.ELEMENT && !c2.dynamicChildren) {
if (c2.patchFlag <= 0 || c2.patchFlag === PatchFlags.HYDRATE_EVENTS) {
c2.el = c1.el
}
traverseStaticChildren(c1, c2)
}
}
}
}
const render: RootRenderFunction = (vnode, container) => {
if (vnode == null) {
if (container._vnode) {
unmount(container._vnode, null, null, true)
}
} else {
patch(container._vnode || null, vnode, container)
}
flushPostFlushCbs()
container._vnode = vnode
}
const internals: RendererInternals = {
p: patch,
um: unmount,
m: move,
r: remove,
mt: mountComponent,
mc: mountChildren,
pc: patchChildren,
pbc: patchBlockChildren,
n: getNextHostNode,
o: options
}
let hydrate: ReturnType<typeof createHydrationFunctions>[0] | undefined
let hydrateNode: ReturnType<typeof createHydrationFunctions>[1] | undefined
if (createHydrationFns) {
;[hydrate, hydrateNode] = createHydrationFns(internals as RendererInternals<
Node,
Element
>)
}
return {
render,
hydrate,
createApp: createAppAPI(render, hydrate)
}
}
这段代码使用的 Vue 是我自己打包的 Vue 文件,在这个 Demo 中 Vue 做了什么事情才能够达到我们这样的效果呢?