108 lines
2.5 KiB
TypeScript
108 lines
2.5 KiB
TypeScript
import {
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effect,
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stop,
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isValue,
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Value,
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ReactiveEffectOptions
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} from '@vue/observer'
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import { queueJob, queuePostFlushCb } from './scheduler'
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import { EMPTY_OBJ, isObject, isArray } from '@vue/shared'
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import { recordEffect } from './apiState'
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export interface WatchOptions {
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lazy?: boolean
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flush?: 'pre' | 'post' | 'sync'
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deep?: boolean
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onTrack?: ReactiveEffectOptions['onTrack']
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onTrigger?: ReactiveEffectOptions['onTrigger']
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}
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type WatcherSource<T> = Value<T> | (() => T)
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const invoke = (fn: Function) => fn()
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export function watch<T>(
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source: WatcherSource<T> | WatcherSource<T>[],
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cb?: <V extends T>(
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newValue: V,
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oldValue: V,
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onInvalidate: (fn: () => void) => void
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) => any | void,
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{ lazy, flush, deep, onTrack, onTrigger }: WatchOptions = EMPTY_OBJ
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): () => void {
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const scheduler =
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flush === 'sync' ? invoke : flush === 'pre' ? queueJob : queuePostFlushCb
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const baseGetter = isArray(source)
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? () => source.map(s => (isValue(s) ? s.value : s()))
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: isValue(source)
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? () => source.value
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: source
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const getter = deep ? () => traverse(baseGetter()) : baseGetter
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let cleanup: any
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const registerCleanup = (fn: () => void) => {
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// TODO wrap the cleanup fn for error handling
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cleanup = runner.onStop = fn
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}
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let oldValue: any
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const applyCb = cb
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? () => {
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const newValue = runner()
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if (deep || newValue !== oldValue) {
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// cleanup before running cb again
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if (cleanup) {
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cleanup()
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}
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// TODO handle error (including ASYNC)
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try {
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cb(newValue, oldValue, registerCleanup)
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} catch (e) {}
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oldValue = newValue
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}
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}
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: void 0
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const runner = effect(getter, {
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lazy: true,
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// so it runs before component update effects in pre flush mode
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computed: true,
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onTrack,
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onTrigger,
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scheduler: applyCb ? () => scheduler(applyCb) : void 0
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})
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if (!lazy) {
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applyCb && scheduler(applyCb)
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} else {
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oldValue = runner()
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}
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recordEffect(runner)
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return () => {
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stop(runner)
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}
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}
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function traverse(value: any, seen: Set<any> = new Set()) {
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if (!isObject(value) || seen.has(value)) {
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return
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}
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seen.add(value)
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if (isArray(value)) {
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for (let i = 0; i < value.length; i++) {
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traverse(value[i], seen)
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}
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} else if (value instanceof Map || value instanceof Set) {
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;(value as any).forEach((v: any) => {
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traverse(v, seen)
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})
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} else {
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for (const key in value) {
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traverse(value[key], seen)
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}
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}
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return value
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}
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