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

312 lines
7.6 KiB
TypeScript

import {
effect,
stop,
isRef,
Ref,
ComputedRef,
ReactiveEffectOptions
} from '@vue/reactivity'
import { queueJob } from './scheduler'
import {
EMPTY_OBJ,
isObject,
isArray,
isFunction,
isString,
hasChanged,
NOOP,
remove
} from '@vue/shared'
import {
currentInstance,
ComponentInternalInstance,
currentSuspense,
Data,
isInSSRComponentSetup,
recordInstanceBoundEffect
} from './component'
import {
ErrorCodes,
callWithErrorHandling,
callWithAsyncErrorHandling
} from './errorHandling'
import { onBeforeUnmount } from './apiLifecycle'
import { queuePostRenderEffect } from './renderer'
import { warn } from './warning'
export type WatchEffect = (onCleanup: CleanupRegistrator) => void
export type WatchSource<T = any> = Ref<T> | ComputedRef<T> | (() => T)
export type WatchCallback<V = any, OV = any> = (
value: V,
oldValue: OV,
onCleanup: CleanupRegistrator
) => any
type MapSources<T> = {
[K in keyof T]: T[K] extends WatchSource<infer V> ? V : never
}
type MapOldSources<T, Immediate> = {
[K in keyof T]: T[K] extends WatchSource<infer V>
? Immediate extends true ? (V | undefined) : V
: never
}
export type CleanupRegistrator = (invalidate: () => void) => void
export interface BaseWatchOptions {
flush?: 'pre' | 'post' | 'sync'
onTrack?: ReactiveEffectOptions['onTrack']
onTrigger?: ReactiveEffectOptions['onTrigger']
}
export interface WatchOptions<Immediate = boolean> extends BaseWatchOptions {
immediate?: Immediate
deep?: boolean
}
export type StopHandle = () => void
const invoke = (fn: Function) => fn()
// initial value for watchers to trigger on undefined initial values
const INITIAL_WATCHER_VALUE = {}
// overload #1: simple effect
export function watch(
effect: WatchEffect,
options?: BaseWatchOptions
): StopHandle
// overload #2: single source + cb
export function watch<T, Immediate extends Readonly<boolean> = false>(
source: WatchSource<T>,
cb: WatchCallback<T, Immediate extends true ? (T | undefined) : T>,
options?: WatchOptions<Immediate>
): StopHandle
// overload #3: array of multiple sources + cb
// Readonly constraint helps the callback to correctly infer value types based
// on position in the source array. Otherwise the values will get a union type
// of all possible value types.
export function watch<
T extends Readonly<WatchSource<unknown>[]>,
Immediate extends Readonly<boolean> = false
>(
sources: T,
cb: WatchCallback<MapSources<T>, MapOldSources<T, Immediate>>,
options?: WatchOptions<Immediate>
): StopHandle
// implementation
export function watch<T = any>(
effectOrSource: WatchSource<T> | WatchSource<T>[] | WatchEffect,
cbOrOptions?: WatchCallback<T> | WatchOptions,
options?: WatchOptions
): StopHandle {
if (isFunction(cbOrOptions)) {
// watch(source, cb)
return doWatch(effectOrSource, cbOrOptions, options)
} else {
// watch(effect)
return doWatch(effectOrSource, null, cbOrOptions)
}
}
function doWatch(
source: WatchSource | WatchSource[] | WatchEffect,
cb: WatchCallback | null,
{ immediate, deep, flush, onTrack, onTrigger }: WatchOptions = EMPTY_OBJ
): StopHandle {
if (__DEV__ && !cb) {
if (immediate !== undefined) {
warn(
`watch() "immediate" option is only respected when using the ` +
`watch(source, callback) signature.`
)
}
if (deep !== undefined) {
warn(
`watch() "deep" option is only respected when using the ` +
`watch(source, callback) signature.`
)
}
}
const instance = currentInstance
const suspense = currentSuspense
let getter: () => any
if (isArray(source)) {
getter = () =>
source.map(
s =>
isRef(s)
? s.value
: callWithErrorHandling(s, instance, ErrorCodes.WATCH_GETTER)
)
} else if (isRef(source)) {
getter = () => source.value
} else if (cb) {
// getter with cb
getter = () =>
callWithErrorHandling(source, instance, ErrorCodes.WATCH_GETTER)
} else {
// no cb -> simple effect
getter = () => {
if (instance && instance.isUnmounted) {
return
}
if (cleanup) {
cleanup()
}
return callWithErrorHandling(
source,
instance,
ErrorCodes.WATCH_CALLBACK,
[registerCleanup]
)
}
}
if (deep) {
const baseGetter = getter
getter = () => traverse(baseGetter())
}
let cleanup: Function
const registerCleanup: CleanupRegistrator = (fn: () => void) => {
cleanup = runner.options.onStop = () => {
callWithErrorHandling(fn, instance, ErrorCodes.WATCH_CLEANUP)
}
}
// in SSR there is no need to setup an actual effect, and it should be noop
// unless it's eager
if (__NODE_JS__ && isInSSRComponentSetup) {
if (!cb) {
getter()
} else if (immediate) {
callWithAsyncErrorHandling(cb, instance, ErrorCodes.WATCH_CALLBACK, [
getter(),
undefined,
registerCleanup
])
}
return NOOP
}
let oldValue = isArray(source) ? [] : INITIAL_WATCHER_VALUE
const applyCb = cb
? () => {
if (instance && instance.isUnmounted) {
return
}
const newValue = runner()
if (deep || hasChanged(newValue, oldValue)) {
// cleanup before running cb again
if (cleanup) {
cleanup()
}
callWithAsyncErrorHandling(cb, instance, ErrorCodes.WATCH_CALLBACK, [
newValue,
// pass undefined as the old value when it's changed for the first time
oldValue === INITIAL_WATCHER_VALUE ? undefined : oldValue,
registerCleanup
])
oldValue = newValue
}
}
: void 0
let scheduler: (job: () => any) => void
if (flush === 'sync') {
scheduler = invoke
} else if (flush === 'pre') {
scheduler = job => {
if (!instance || instance.vnode.el != null) {
queueJob(job)
} else {
// with 'pre' option, the first call must happen before
// the component is mounted so it is called synchronously.
job()
}
}
} else {
scheduler = job => {
queuePostRenderEffect(job, suspense)
}
}
const runner = effect(getter, {
lazy: true,
// so it runs before component update effects in pre flush mode
computed: true,
onTrack,
onTrigger,
scheduler: applyCb ? () => scheduler(applyCb) : scheduler
})
recordInstanceBoundEffect(runner)
// initial run
if (applyCb) {
if (immediate) {
applyCb()
} else {
oldValue = runner()
}
} else {
runner()
}
return () => {
stop(runner)
if (instance) {
remove(instance.effects!, runner)
}
}
}
// this.$watch
export function instanceWatch(
this: ComponentInternalInstance,
source: string | Function,
cb: Function,
options?: WatchOptions
): StopHandle {
const ctx = this.proxy as Data
const getter = isString(source) ? () => ctx[source] : source.bind(ctx)
const stop = watch(getter, cb.bind(ctx), options)
onBeforeUnmount(stop, this)
return stop
}
function traverse(value: unknown, seen: Set<unknown> = new Set()) {
if (!isObject(value) || seen.has(value)) {
return
}
seen.add(value)
if (isArray(value)) {
for (let i = 0; i < value.length; i++) {
traverse(value[i], seen)
}
} else if (value instanceof Map) {
value.forEach((v, key) => {
// to register mutation dep for existing keys
traverse(value.get(key), seen)
})
} else if (value instanceof Set) {
value.forEach(v => {
traverse(v, seen)
})
} else {
for (const key in value) {
traverse(value[key], seen)
}
}
return value
}