forked from MapComplete/MapComplete
755 lines
24 KiB
TypeScript
755 lines
24 KiB
TypeScript
import { Utils } from "../Utils"
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/**
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* Various static utils
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*/
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export class Stores {
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public static Chronic(millis: number, asLong: () => boolean = undefined): Store<Date> {
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const source = new UIEventSource<Date>(undefined)
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function run() {
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source.setData(new Date())
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if (asLong === undefined || asLong()) {
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window.setTimeout(run, millis)
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}
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}
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run()
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return source
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}
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public static FromPromiseWithErr<T>(
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promise: Promise<T>
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): Store<{ success: T } | { error: any }> {
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return UIEventSource.FromPromiseWithErr(promise)
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}
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/**
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* Converts a promise into a UIVentsource, sets the UIEVentSource when the result is calculated.
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* If the promise fails, the value will stay undefined
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* @param promise
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* @constructor
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*/
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public static FromPromise<T>(promise: Promise<T>): Store<T> {
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const src = new UIEventSource<T>(undefined)
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promise?.then((d) => src.setData(d))
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promise?.catch((err) => console.warn("Promise failed:", err))
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return src
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}
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public static flatten<X>(source: Store<Store<X>>, possibleSources?: Store<any>[]): Store<X> {
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return UIEventSource.flatten(source, possibleSources)
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}
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/**
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* Given a UIEVentSource with a list, returns a new UIEventSource which is only updated if the _contents_ of the list are different.
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* E.g.
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* const src = new UIEventSource([1,2,3])
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* const stable = UIEventSource.ListStabilized(src)
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* src.addCallback(_ => console.log("src pinged"))
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* stable.addCallback(_ => console.log("stable pinged))
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* src.setDate([...src.data])
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*
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* This will only trigger 'src pinged'
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*
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* @param src
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* @constructor
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*/
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public static ListStabilized<T>(src: Store<T[]>): Store<T[]> {
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const stable = new UIEventSource<T[]>(undefined)
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src.addCallbackAndRun((list) => {
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if (list === undefined) {
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stable.setData(undefined)
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return
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}
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const oldList = stable.data
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if (oldList === list) {
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return
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}
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if (oldList == list) {
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return
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}
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if (oldList === undefined || oldList.length !== list.length) {
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stable.setData(list)
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return
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}
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for (let i = 0; i < list.length; i++) {
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if (oldList[i] !== list[i]) {
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stable.setData(list)
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return
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}
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}
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// No actual changes, so we don't do anything
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return
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})
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return stable
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}
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}
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export abstract class Store<T> {
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abstract readonly data: T
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/**
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* OPtional value giving a title to the UIEventSource, mainly used for debugging
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*/
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public readonly tag: string | undefined
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constructor(tag: string = undefined) {
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this.tag = tag
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if (tag === undefined || tag === "") {
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let createStack = Utils.runningFromConsole
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if (!Utils.runningFromConsole) {
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createStack = window.location.hostname === "127.0.0.1"
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}
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if (createStack) {
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const callstack = new Error().stack.split("\n")
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this.tag = callstack[1]
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}
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}
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}
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abstract map<J>(f: (t: T) => J): Store<J>
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abstract map<J>(f: (t: T) => J, extraStoresToWatch: Store<any>[]): Store<J>
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/**
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* Add a callback function which will run on future data changes
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*/
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abstract addCallback(callback: (data: T) => void): () => void
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/**
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* Adds a callback function, which will be run immediately.
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* Only triggers if the current data is defined
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*/
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abstract addCallbackAndRunD(callback: (data: T) => void): () => void
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/**
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* Add a callback function which will run on future data changes
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* Only triggers if the data is defined
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*/
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abstract addCallbackD(callback: (data: T) => void): () => void
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/**
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* Adds a callback function, which will be run immediately.
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* Only triggers if the current data is defined
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*/
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abstract addCallbackAndRun(callback: (data: T) => void): () => void
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public withEqualityStabilized(
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comparator: (t: T | undefined, t1: T | undefined) => boolean
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): Store<T> {
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let oldValue = undefined
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return this.map((v) => {
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if (v == oldValue) {
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return oldValue
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}
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if (comparator(oldValue, v)) {
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return oldValue
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}
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oldValue = v
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return v
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})
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}
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/**
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* Monadic bind function
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*
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* // simple test with bound and immutablestores
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* const src = new UIEventSource<number>(3)
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* const bound = src.bind(i => new ImmutableStore(i * 2))
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* let lastValue = undefined;
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* bound.addCallbackAndRun(v => lastValue = v);
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* lastValue // => 6
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* src.setData(21)
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* lastValue // => 42
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*
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* // simple test with bind over a mapped value
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* const src = new UIEventSource<number>(0)
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* const srcs : UIEventSource<string>[] = [new UIEventSource<string>("a"), new UIEventSource<string>("b")]
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* const bound = src.map(i => -i).bind(i => srcs[i])
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* let lastValue : string = undefined;
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* bound.addCallbackAndRun(v => lastValue = v);
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* lastValue // => "a"
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* src.setData(-1)
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* lastValue // => "b"
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* srcs[1].setData("xyz")
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* lastValue // => "xyz"
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* srcs[0].setData("def")
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* lastValue // => "xyz"
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* src.setData(0)
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* lastValue // => "def"
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*
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*
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*
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* // advanced test with bound
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* const src = new UIEventSource<number>(0)
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* const srcs : UIEventSource<string>[] = [new UIEventSource<string>("a"), new UIEventSource<string>("b")]
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* const bound = src.bind(i => srcs[i])
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* let lastValue : string = undefined;
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* bound.addCallbackAndRun(v => lastValue = v);
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* lastValue // => "a"
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* src.setData(1)
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* lastValue // => "b"
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* srcs[1].setData("xyz")
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* lastValue // => "xyz"
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* srcs[0].setData("def")
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* lastValue // => "xyz"
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* src.setData(0)
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* lastValue // => "def"
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*/
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public bind<X>(f: (t: T) => Store<X>): Store<X> {
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const mapped = this.map(f)
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const sink = new UIEventSource<X>(undefined)
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const seenEventSources = new Set<Store<X>>()
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mapped.addCallbackAndRun((newEventSource) => {
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if (newEventSource === null) {
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sink.setData(null)
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} else if (newEventSource === undefined) {
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sink.setData(undefined)
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} else if (!seenEventSources.has(newEventSource)) {
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seenEventSources.add(newEventSource)
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newEventSource.addCallbackAndRun((resultData) => {
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if (mapped.data === newEventSource) {
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sink.setData(resultData)
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}
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})
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} else {
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// Already seen, so we don't have to add a callback, just update the value
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sink.setData(newEventSource.data)
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}
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})
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return sink
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}
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public stabilized(millisToStabilize): Store<T> {
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if (Utils.runningFromConsole) {
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return this
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}
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const newSource = new UIEventSource<T>(this.data)
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this.addCallback((latestData) => {
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window.setTimeout(() => {
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if (this.data == latestData) {
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// compare by reference
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newSource.setData(latestData)
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}
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}, millisToStabilize)
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})
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return newSource
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}
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public AsPromise(condition?: (t: T) => boolean): Promise<T> {
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const self = this
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condition = condition ?? ((t) => t !== undefined)
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return new Promise((resolve) => {
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if (condition(self.data)) {
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resolve(self.data)
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} else {
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self.addCallbackD((data) => {
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resolve(data)
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return true // return true to unregister as we only need to be called once
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})
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}
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})
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}
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}
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export class ImmutableStore<T> extends Store<T> {
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public readonly data: T
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private static readonly pass: () => void = () => {}
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constructor(data: T) {
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super()
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this.data = data
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}
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addCallback(callback: (data: T) => void): () => void {
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// pass: data will never change
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return ImmutableStore.pass
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}
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addCallbackAndRun(callback: (data: T) => void): () => void {
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callback(this.data)
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// no callback registry: data will never change
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return ImmutableStore.pass
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}
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addCallbackAndRunD(callback: (data: T) => void): () => void {
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if (this.data !== undefined) {
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callback(this.data)
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}
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// no callback registry: data will never change
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return ImmutableStore.pass
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}
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addCallbackD(callback: (data: T) => void): () => void {
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// pass: data will never change
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return ImmutableStore.pass
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}
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map<J>(f: (t: T) => J, extraStores: Store<any>[] = undefined): ImmutableStore<J> {
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if (extraStores?.length > 0) {
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return new MappedStore(this, f, extraStores, undefined, f(this.data))
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}
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return new ImmutableStore<J>(f(this.data))
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}
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}
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/**
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* Keeps track of the callback functions
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*/
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class ListenerTracker<T> {
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private readonly _callbacks: ((t: T) => boolean | void | any)[] = []
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public pingCount = 0
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/**
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* Adds a callback which can be called; a function to unregister is returned
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*/
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public addCallback(callback: (t: T) => boolean | void | any): () => void {
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if (callback === console.log) {
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// This ^^^ actually works!
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throw "Don't add console.log directly as a callback - you'll won't be able to find it afterwards. Wrap it in a lambda instead."
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}
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this._callbacks.push(callback)
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// Give back an unregister-function!
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return () => {
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const index = this._callbacks.indexOf(callback)
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if (index >= 0) {
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this._callbacks.splice(index, 1)
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}
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}
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}
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/**
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* Call all the callbacks.
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* Returns the number of registered callbacks
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*/
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public ping(data: T): number {
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this.pingCount++
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let toDelete = undefined
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let startTime = new Date().getTime() / 1000
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for (const callback of this._callbacks) {
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if (callback(data) === true) {
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// This callback wants to be deleted
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// Note: it has to return precisely true in order to avoid accidental deletions
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if (toDelete === undefined) {
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toDelete = [callback]
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} else {
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toDelete.push(callback)
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}
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}
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}
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let endTime = new Date().getTime() / 1000
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if (endTime - startTime > 500) {
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console.trace(
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"Warning: a ping took more then 500ms; this is probably a performance issue"
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)
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}
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if (toDelete !== undefined) {
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for (const toDeleteElement of toDelete) {
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this._callbacks.splice(this._callbacks.indexOf(toDeleteElement), 1)
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}
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}
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return this._callbacks.length
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}
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length() {
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return this._callbacks.length
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}
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}
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/**
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* The mapped store is a helper type which does the mapping of a function.
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* It'll fuse
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*/
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class MappedStore<TIn, T> extends Store<T> {
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private _upstream: Store<TIn>
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private _upstreamCallbackHandler: ListenerTracker<TIn> | undefined
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private _upstreamPingCount: number = -1
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private _unregisterFromUpstream: () => void
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private _f: (t: TIn) => T
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private readonly _extraStores: Store<any>[] | undefined
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private _unregisterFromExtraStores: (() => void)[] | undefined
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private _callbacks: ListenerTracker<T> = new ListenerTracker<T>()
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private static readonly pass: () => {}
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constructor(
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upstream: Store<TIn>,
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f: (t: TIn) => T,
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extraStores: Store<any>[],
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upstreamListenerHandler: ListenerTracker<TIn> | undefined,
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initialState: T
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) {
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super()
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this._upstream = upstream
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this._upstreamCallbackHandler = upstreamListenerHandler
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this._f = f
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this._data = initialState
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this._upstreamPingCount = upstreamListenerHandler?.pingCount
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this._extraStores = extraStores
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this.registerCallbacksToUpstream()
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}
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private _data: T
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private _callbacksAreRegistered = false
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/**
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* Gets the current data from the store
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*
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* const src = new UIEventSource(21)
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* const mapped = src.map(i => i * 2)
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* src.setData(3)
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* mapped.data // => 6
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*
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*/
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get data(): T {
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if (!this._callbacksAreRegistered) {
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// Callbacks are not registered, so we haven't been listening for updates from the upstream which might have changed
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if (this._upstreamCallbackHandler?.pingCount != this._upstreamPingCount) {
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// Upstream has pinged - let's update our data first
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this._data = this._f(this._upstream.data)
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}
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return this._data
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}
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return this._data
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}
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map<J>(f: (t: T) => J, extraStores: Store<any>[] = undefined): Store<J> {
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let stores: Store<any>[] = undefined
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if (extraStores?.length > 0 || this._extraStores?.length > 0) {
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stores = []
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}
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if (extraStores?.length > 0) {
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stores.push(...extraStores)
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}
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if (this._extraStores?.length > 0) {
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this._extraStores?.forEach((store) => {
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if (stores.indexOf(store) < 0) {
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stores.push(store)
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}
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})
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}
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return new MappedStore(
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this,
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f, // we could fuse the functions here (e.g. data => f(this._f(data), but this might result in _f being calculated multiple times, breaking things
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stores,
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this._callbacks,
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f(this.data)
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)
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}
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private unregisterFromUpstream() {
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console.log("Unregistering callbacks for", this.tag)
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this._callbacksAreRegistered = false
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this._unregisterFromUpstream()
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this._unregisterFromExtraStores?.forEach((unr) => unr())
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}
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private registerCallbacksToUpstream() {
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const self = this
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this._unregisterFromUpstream = this._upstream.addCallback((_) => self.update())
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this._unregisterFromExtraStores = this._extraStores?.map((store) =>
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store?.addCallback((_) => self.update())
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)
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this._callbacksAreRegistered = true
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}
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private update(): void {
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const newData = this._f(this._upstream.data)
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this._upstreamPingCount = this._upstreamCallbackHandler?.pingCount
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if (this._data == newData) {
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return
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}
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this._data = newData
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this._callbacks.ping(this._data)
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}
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addCallback(callback: (data: T) => any | boolean | void): () => void {
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if (!this._callbacksAreRegistered) {
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// This is the first callback that is added
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// We register this 'map' to the upstream object and all the streams
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this.registerCallbacksToUpstream()
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}
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const unregister = this._callbacks.addCallback(callback)
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return () => {
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unregister()
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if (this._callbacks.length() == 0) {
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this.unregisterFromUpstream()
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}
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}
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}
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addCallbackAndRun(callback: (data: T) => any | boolean | void): () => void {
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const unregister = this.addCallback(callback)
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const doRemove = callback(this.data)
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if (doRemove === true) {
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unregister()
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return MappedStore.pass
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}
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return unregister
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}
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addCallbackAndRunD(callback: (data: T) => any | boolean | void): () => void {
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return this.addCallbackAndRun((data) => {
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if (data !== undefined) {
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return callback(data)
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}
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})
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}
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addCallbackD(callback: (data: T) => any | boolean | void): () => void {
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return this.addCallback((data) => {
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if (data !== undefined) {
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return callback(data)
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}
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})
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}
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}
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export class UIEventSource<T> extends Store<T> {
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public data: T
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_callbacks: ListenerTracker<T> = new ListenerTracker<T>()
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private static readonly pass: () => {}
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constructor(data: T, tag: string = "") {
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super(tag)
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this.data = data
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}
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public static flatten<X>(
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source: Store<Store<X>>,
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possibleSources?: Store<any>[]
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): UIEventSource<X> {
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const sink = new UIEventSource<X>(source.data?.data)
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source.addCallback((latestData) => {
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sink.setData(latestData?.data)
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latestData.addCallback((data) => {
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if (source.data !== latestData) {
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return true
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}
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sink.setData(data)
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})
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})
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for (const possibleSource of possibleSources ?? []) {
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possibleSource?.addCallback(() => {
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sink.setData(source.data?.data)
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})
|
|
}
|
|
|
|
return sink
|
|
}
|
|
|
|
/**
|
|
* Converts a promise into a UIVentsource, sets the UIEVentSource when the result is calculated.
|
|
* If the promise fails, the value will stay undefined, but 'onError' will be called
|
|
*/
|
|
public static FromPromise<T>(
|
|
promise: Promise<T>,
|
|
onError: (e: any) => void = undefined
|
|
): UIEventSource<T> {
|
|
const src = new UIEventSource<T>(undefined)
|
|
promise?.then((d) => src.setData(d))
|
|
promise?.catch((err) => {
|
|
if (onError !== undefined) {
|
|
onError(err)
|
|
} else {
|
|
console.warn("Promise failed:", err)
|
|
}
|
|
})
|
|
return src
|
|
}
|
|
|
|
/**
|
|
* Converts a promise into a UIVentsource, sets the UIEVentSource when the result is calculated.
|
|
* If the promise fails, the value will stay undefined
|
|
* @param promise
|
|
* @constructor
|
|
*/
|
|
public static FromPromiseWithErr<T>(
|
|
promise: Promise<T>
|
|
): UIEventSource<{ success: T } | { error: any }> {
|
|
const src = new UIEventSource<{ success: T } | { error: any }>(undefined)
|
|
promise?.then((d) => src.setData({ success: d }))
|
|
promise?.catch((err) => src.setData({ error: err }))
|
|
return src
|
|
}
|
|
|
|
public static asFloat(source: UIEventSource<string>): UIEventSource<number> {
|
|
return source.sync(
|
|
(str) => {
|
|
let parsed = parseFloat(str)
|
|
return isNaN(parsed) ? undefined : parsed
|
|
},
|
|
[],
|
|
(fl) => {
|
|
if (fl === undefined || isNaN(fl)) {
|
|
return undefined
|
|
}
|
|
return ("" + fl).substr(0, 8)
|
|
}
|
|
)
|
|
}
|
|
|
|
/**
|
|
* Adds a callback
|
|
*
|
|
* If the result of the callback is 'true', the callback is considered finished and will be removed again
|
|
* @param callback
|
|
*/
|
|
public addCallback(callback: (latestData: T) => boolean | void | any): () => void {
|
|
return this._callbacks.addCallback(callback)
|
|
}
|
|
|
|
public addCallbackAndRun(callback: (latestData: T) => boolean | void | any): () => void {
|
|
const doDeleteCallback = callback(this.data)
|
|
if (doDeleteCallback !== true) {
|
|
return this.addCallback(callback)
|
|
} else {
|
|
return UIEventSource.pass
|
|
}
|
|
}
|
|
|
|
public addCallbackAndRunD(callback: (data: T) => void): () => void {
|
|
return this.addCallbackAndRun((data) => {
|
|
if (data !== undefined && data !== null) {
|
|
return callback(data)
|
|
}
|
|
})
|
|
}
|
|
|
|
public addCallbackD(callback: (data: T) => void): () => void {
|
|
return this.addCallback((data) => {
|
|
if (data !== undefined && data !== null) {
|
|
return callback(data)
|
|
}
|
|
})
|
|
}
|
|
|
|
public setData(t: T): UIEventSource<T> {
|
|
if (this.data == t) {
|
|
// MUST COMPARE BY REFERENCE!
|
|
return
|
|
}
|
|
this.data = t
|
|
this._callbacks.ping(t)
|
|
return this
|
|
}
|
|
|
|
public ping(): void {
|
|
this._callbacks.ping(this.data)
|
|
}
|
|
|
|
/**
|
|
* Monoidal map which results in a read-only store
|
|
* Given a function 'f', will construct a new UIEventSource where the contents will always be "f(this.data)'
|
|
* @param f: The transforming function
|
|
* @param extraSources: also trigger the update if one of these sources change
|
|
*
|
|
* const src = new UIEventSource<number>(10)
|
|
* const store = src.map(i => i * 2)
|
|
* store.data // => 20
|
|
* let srcSeen = undefined;
|
|
* src.addCallback(v => {
|
|
* console.log("Triggered")
|
|
* srcSeen = v
|
|
* })
|
|
* let lastSeen = undefined
|
|
* store.addCallback(v => {
|
|
* console.log("Triggered!")
|
|
* lastSeen = v
|
|
* })
|
|
* src.setData(21)
|
|
* srcSeen // => 21
|
|
* lastSeen // => 42
|
|
*/
|
|
public map<J>(f: (t: T) => J, extraSources: Store<any>[] = []): Store<J> {
|
|
return new MappedStore(this, f, extraSources, this._callbacks, f(this.data))
|
|
}
|
|
/**
|
|
* Monoidal map which results in a read-only store. 'undefined' is passed 'as is'
|
|
* Given a function 'f', will construct a new UIEventSource where the contents will always be "f(this.data)'
|
|
*/
|
|
public mapD<J>(f: (t: T) => J, extraSources: Store<any>[] = []): Store<J | undefined> {
|
|
return new MappedStore(
|
|
this,
|
|
(t) => {
|
|
if (t === undefined) {
|
|
return undefined
|
|
}
|
|
return f(t)
|
|
},
|
|
extraSources,
|
|
this._callbacks,
|
|
this.data === undefined ? undefined : f(this.data)
|
|
)
|
|
}
|
|
|
|
/**
|
|
* Two way sync with functions in both directions
|
|
* Given a function 'f', will construct a new UIEventSource where the contents will always be "f(this.data)'
|
|
* @param f: The transforming function
|
|
* @param extraSources: also trigger the update if one of these sources change
|
|
* @param g: a 'backfunction to let the sync run in two directions. (data of the new UIEVEntSource, currentData) => newData
|
|
* @param allowUnregister: if set, the update will be halted if no listeners are registered
|
|
*/
|
|
public sync<J>(
|
|
f: (t: T) => J,
|
|
extraSources: Store<any>[],
|
|
g: (j: J, t: T) => T,
|
|
allowUnregister = false
|
|
): UIEventSource<J> {
|
|
const self = this
|
|
|
|
const stack = new Error().stack.split("\n")
|
|
const callee = stack[1]
|
|
|
|
const newSource = new UIEventSource<J>(f(this.data), "map(" + this.tag + ")@" + callee)
|
|
|
|
const update = function () {
|
|
newSource.setData(f(self.data))
|
|
return allowUnregister && newSource._callbacks.length() === 0
|
|
}
|
|
|
|
this.addCallback(update)
|
|
for (const extraSource of extraSources) {
|
|
extraSource?.addCallback(update)
|
|
}
|
|
|
|
if (g !== undefined) {
|
|
newSource.addCallback((latest) => {
|
|
self.setData(g(latest, self.data))
|
|
})
|
|
}
|
|
|
|
return newSource
|
|
}
|
|
|
|
public syncWith(otherSource: UIEventSource<T>, reverseOverride = false): UIEventSource<T> {
|
|
this.addCallback((latest) => otherSource.setData(latest))
|
|
const self = this
|
|
otherSource.addCallback((latest) => self.setData(latest))
|
|
if (reverseOverride) {
|
|
if (otherSource.data !== undefined) {
|
|
this.setData(otherSource.data)
|
|
}
|
|
} else if (this.data === undefined) {
|
|
this.setData(otherSource.data)
|
|
} else {
|
|
otherSource.setData(this.data)
|
|
}
|
|
return this
|
|
}
|
|
}
|