vue3-yuanma/packages/runtime-core/src/components/KeepAlive.ts
2020-02-18 13:52:59 -05:00

303 lines
8.7 KiB
TypeScript

import {
Component,
getCurrentInstance,
FunctionalComponent,
SetupContext,
ComponentInternalInstance,
LifecycleHooks,
currentInstance
} from '../component'
import { VNode, cloneVNode, isVNode, VNodeProps } from '../vnode'
import { warn } from '../warning'
import { onBeforeUnmount, injectHook, onUnmounted } from '../apiLifecycle'
import { isString, isArray, ShapeFlags, remove } from '@vue/shared'
import { watch } from '../apiWatch'
import { SuspenseBoundary } from './Suspense'
import {
RendererInternals,
queuePostRenderEffect,
invokeHooks,
MoveType
} from '../renderer'
import { setTransitionHooks } from './BaseTransition'
type MatchPattern = string | RegExp | string[] | RegExp[]
export interface KeepAliveProps {
include?: MatchPattern
exclude?: MatchPattern
max?: number | string
}
type CacheKey = string | number | Component
type Cache = Map<CacheKey, VNode>
type Keys = Set<CacheKey>
export interface KeepAliveSink {
renderer: RendererInternals
parentSuspense: SuspenseBoundary | null
activate: (vnode: VNode, container: object, anchor: object | null) => void
deactivate: (vnode: VNode) => void
}
export const isKeepAlive = (vnode: VNode): boolean =>
(vnode.type as any).__isKeepAlive
const KeepAliveImpl = {
name: `KeepAlive`,
// Marker for special handling inside the renderer. We are not using a ===
// check directly on KeepAlive in the renderer, because importing it directly
// would prevent it from being tree-shaken.
__isKeepAlive: true,
props: {
include: [String, RegExp, Array],
exclude: [String, RegExp, Array],
max: [String, Number]
},
setup(props: KeepAliveProps, { slots }: SetupContext) {
const cache: Cache = new Map()
const keys: Keys = new Set()
let current: VNode | null = null
const instance = getCurrentInstance()!
// KeepAlive communicates with the instantiated renderer via the "sink"
// where the renderer passes in platform-specific functions, and the
// KeepAlive instance exposes activate/deactivate implementations.
// The whole point of this is to avoid importing KeepAlive directly in the
// renderer to facilitate tree-shaking.
const sink = instance.sink as KeepAliveSink
const {
renderer: {
m: move,
um: _unmount,
o: { createElement }
},
parentSuspense
} = sink
const storageContainer = createElement('div')
sink.activate = (vnode, container, anchor) => {
move(vnode, container, anchor, MoveType.ENTER, parentSuspense)
queuePostRenderEffect(() => {
const component = vnode.component!
component.isDeactivated = false
if (component.a !== null) {
invokeHooks(component.a)
}
}, parentSuspense)
}
sink.deactivate = (vnode: VNode) => {
move(vnode, storageContainer, null, MoveType.LEAVE, parentSuspense)
queuePostRenderEffect(() => {
const component = vnode.component!
if (component.da !== null) {
invokeHooks(component.da)
}
component.isDeactivated = true
}, parentSuspense)
}
function unmount(vnode: VNode) {
// reset the shapeFlag so it can be properly unmounted
vnode.shapeFlag = ShapeFlags.STATEFUL_COMPONENT
_unmount(vnode, instance, parentSuspense)
}
function pruneCache(filter?: (name: string) => boolean) {
cache.forEach((vnode, key) => {
const name = getName(vnode.type as Component)
if (name && (!filter || !filter(name))) {
pruneCacheEntry(key)
}
})
}
function pruneCacheEntry(key: CacheKey) {
const cached = cache.get(key) as VNode
if (!current || cached.type !== current.type) {
unmount(cached)
} else if (current) {
// current active instance should no longer be kept-alive.
// we can't unmount it now but it might be later, so reset its flag now.
current.shapeFlag = ShapeFlags.STATEFUL_COMPONENT
}
cache.delete(key)
keys.delete(key)
}
watch(
() => [props.include, props.exclude],
([include, exclude]) => {
include && pruneCache(name => matches(include, name))
exclude && pruneCache(name => matches(exclude, name))
}
)
onBeforeUnmount(() => {
cache.forEach(unmount)
})
return () => {
if (!slots.default) {
return null
}
const children = slots.default()
let vnode = children[0]
if (children.length > 1) {
if (__DEV__) {
warn(`KeepAlive should contain exactly one component child.`)
}
current = null
return children
} else if (
!isVNode(vnode) ||
!(vnode.shapeFlag & ShapeFlags.STATEFUL_COMPONENT)
) {
current = null
return vnode
}
const comp = vnode.type as Component
const name = getName(comp)
const { include, exclude, max } = props
if (
(include && (!name || !matches(include, name))) ||
(exclude && name && matches(exclude, name))
) {
return vnode
}
const key = vnode.key == null ? comp : vnode.key
const cached = cache.get(key)
// clone vnode if it's reused because we are going to mutate it
if (vnode.el) {
vnode = cloneVNode(vnode)
}
cache.set(key, vnode)
if (cached) {
// copy over mounted state
vnode.el = cached.el
vnode.anchor = cached.anchor
vnode.component = cached.component
if (vnode.transition) {
// recursively update transition hooks on subTree
setTransitionHooks(vnode, vnode.transition!)
}
// avoid vnode being mounted as fresh
vnode.shapeFlag |= ShapeFlags.COMPONENT_KEPT_ALIVE
// make this key the freshest
keys.delete(key)
keys.add(key)
} else {
keys.add(key)
// prune oldest entry
if (max && keys.size > parseInt(max as string, 10)) {
pruneCacheEntry(Array.from(keys)[0])
}
}
// avoid vnode being unmounted
vnode.shapeFlag |= ShapeFlags.COMPONENT_SHOULD_KEEP_ALIVE
current = vnode
return vnode
}
}
}
// export the public type for h/tsx inference
// also to avoid inline import() in generated d.ts files
export const KeepAlive = (KeepAliveImpl as any) as {
new (): {
$props: VNodeProps & KeepAliveProps
}
}
function getName(comp: Component): string | void {
return (comp as FunctionalComponent).displayName || comp.name
}
function matches(pattern: MatchPattern, name: string): boolean {
if (isArray(pattern)) {
return (pattern as any).some((p: string | RegExp) => matches(p, name))
} else if (isString(pattern)) {
return pattern.split(',').indexOf(name) > -1
} else if (pattern.test) {
return pattern.test(name)
}
/* istanbul ignore next */
return false
}
export function onActivated(
hook: Function,
target?: ComponentInternalInstance | null
) {
registerKeepAliveHook(hook, LifecycleHooks.ACTIVATED, target)
}
export function onDeactivated(
hook: Function,
target?: ComponentInternalInstance | null
) {
registerKeepAliveHook(hook, LifecycleHooks.DEACTIVATED, target)
}
function registerKeepAliveHook(
hook: Function & { __wdc?: Function },
type: LifecycleHooks,
target: ComponentInternalInstance | null = currentInstance
) {
// cache the deactivate branch check wrapper for injected hooks so the same
// hook can be properly deduped by the scheduler. "__wdc" stands for "with
// deactivation check".
const wrappedHook =
hook.__wdc ||
(hook.__wdc = () => {
// only fire the hook if the target instance is NOT in a deactivated branch.
let current: ComponentInternalInstance | null = target
while (current) {
if (current.isDeactivated) {
return
}
current = current.parent
}
hook()
})
injectHook(type, wrappedHook, target)
// In addition to registering it on the target instance, we walk up the parent
// chain and register it on all ancestor instances that are keep-alive roots.
// This avoids the need to walk the entire component tree when invoking these
// hooks, and more importantly, avoids the need to track child components in
// arrays.
if (target) {
let current = target.parent
while (current && current.parent) {
if (isKeepAlive(current.parent.vnode)) {
injectToKeepAliveRoot(wrappedHook, type, target, current)
}
current = current.parent
}
}
}
function injectToKeepAliveRoot(
hook: Function,
type: LifecycleHooks,
target: ComponentInternalInstance,
keepAliveRoot: ComponentInternalInstance
) {
injectHook(type, hook, keepAliveRoot, true /* prepend */)
onUnmounted(() => {
remove(keepAliveRoot[type]!, hook)
}, target)
}